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Join us on14th August, 2021

11:00 AM

Department

presents

Chemical Society,of

Chemistry, IIT Kanpur

Session I (11.00-12.30)

11.00-12.30 Poster Session

13.55-14.00 Inauguration: Head, Chemistry Department

Session II (14.00-15.05) Chair: Dr. T. G. Gopakumar

14.00-14.20 Dr. Ritika Gautam “Vaccine design to alleviate the activity of hormones, peptides, and synthetic psychostimulants”

14.20-14.35 Ms. Chetna Yadav “Multi-functional Porous Organic Polymers (POPs): Design, Synthesis and Applications”

14.35-14.50 Ms Priyanka Pandey “Concerted or sequential? – a phase space perspective”

14.50-15.05 Mr. Sabyasachi Sarkar “Diheme Enzyme MauG: Our Understanding towards Nature’s Design”

Session III (15.15 – 16.20) Chair: Dr. Anand Singh

15.15-15.35 Dr. Srinivas Dharavath “Synthesis of Green High Energy Density Materials”

15.35-15.50 Ms. Ritu Gupta “Electrochemical Potential Driven Nanoscale Molecular Layers: From Surface Engineering to Molecular Electronics”

15.50-16.05 Ms. Nidhi Gupta “Intermixing in Ge/Si(001) Heteroepitaxial Growth: Kinetic Monte Carlo Study”

16.05-16.20 Ms. Navya Chauhan “Synthetic routes to nonracemic spiropiperidino indolenines, piperazines, and imidazoquinolines via SN2-type ring opening of aziridines”

Session IV (16.30 – 17.35) Chair: Dr. Ashis K. Patra

16.30-16.50 Dr. Mainak Sadukhan “The curious case of Density Functional Theory”

16.50-17.05 Ms. Shiwangi Maurya “Trimethylamine biodegradation by paracoccus sp. strain DMF”

17.05-17.20 Mr. Rakesh Kumar “Shedding light on transient species involved in Ru-based water oxidation catalysis”

17.20-17.35 Ms. Swathi Swaminathan “Simultaneous utilization of hot holes and hot electrons in plasmon mediated amine photooxidation”

17.35-17.40 Closing Remarks: President, Chemical Society

Poster Session (11.00-12.30)

S.No. Name Title

1 Dibyajyoti Panja Tandem Synthesis of Pyrroles from Nitroarenes and Diols Uti-lizing Caffeine Carbon Supported Cobalt Catalyst

2 Habib Ali Enhanced two- photon activity with extended molecular conjugation

3 Nilay Kumar Pal Ni(II)-Catalyzed Oxidative Deamination of Primary Amines by Water

4 Sadhana Singh Synthesis of cyclic palladium formamidinate complex and its reactivity towards the small molecules activation

5 Usha Yadav Sensing of Bacillus Anthracis Biomarker using Tb-probe: A 'Turn-On' sensor

6 Ravi Malik Hydrogen bond dynamics and 2D-IR spectroscopy of aqueous solutions of tertiary butyl alcohol

7 Priyanka Chakraborty High-Valent Cobalt Catalyzed Hydrogen Borrowing Reactions and its Mechanistic Investigations.

8 Anji Babu Kapakayala A novel tool for accurate and efficient prediction of conformations of biomolecules

9 Prabhakar Panday Selectfluor Mediated Difunctionalization of Olefins Towards the Synthesis of Fluoromethylated Morpholines

10 Surender Singh Electronic Structure, Lattice-Dynamics And Superconductivity in Ag-Au Alloys

11 Sadhna Shah Cu-Catalyzed Chemodivergent, Stereoselective Propargylic Dearomatization and Etherification of 2-Naphthols

12 Vimlesh Kumar Ruthenium Catalyzed Stereo- and Chemoselective Cross-Coupling of Vinyl ketones and its Appplication to Total Synthesis of FR-256523

13 Sachchida Nand Pd-Catalyzed Domino Chemo-selective Synthesis of Functionalized 4-(Arylethynyl)Coumarins and their Cu-catalyzed convergent transformation to pyrrolocoumarins and furocoumarins

Oral Presentations

Vaccine design to alleviate the activity of hormones, peptides, and synthetic psychostimulants

Ritika Gautam* Department of Chemistry, IIT Kanpur, Kanpur-208016, India

Email: [email protected] In the last decade, abuse of synthetic psychostimulant drugs (SPD) has become an epidemic. Drugs

consisting of a phenyalkylamine scaffold, and their derivatives are among the earliest and most widely

abused illegal substances in the United States. One such psychostimulant is fenethylline, which is

marketed under the trade name of “Captagon” and is a Schedule I drug. Captagon has an estimated

40% users in the age range of 12-22 in the Middle East. Moreover, the continued abuse of fenethylline

leads to severe adverse events like myocardial infarction, neurotoxicity, and psychosis, yet there is no

FDA-approved medication to treat fenethylline’s abuse or its toxicity. In an effort to develop such

therapeutics we utilized immunopharmacotherapy as a means to limit abuse and potential overdose.

Hereby, I detail the development of first and second generation haptens and identification of a

vaccine that elicits a robust “anti-FEN” immune response in rodents, which in turn dampened

fenethylline’s psychostimulant effect. Importantly, we will also detail a binary mixture study, which

established that the psychostimulant activity of fenethylline originates from the synergistic interaction

between two of its metabolites, amphetamine, and theophylline. An unanticipated finding from this

study was that a binary mixture can have an impact on both the reinforcing potency, and an

effectiveness of the drug.

Figure 1. Simplified representation of drug conjugate immunological pathway and mechanism of action References

1. C. J. Wenthur, R. Gautam, B. Zhou, L.F.Vendruscolo. L. Leggio, K. Janda. Scientific Reports, 2019, 9, 1841-51.

2. P. Miranda, N. Jacob, R. Shirey, R. Gautam, B. Zhou, M.E.Izquierdo, M. Hixon, J. Hart, L. Ueno, P. Vogt, K. Janda.

Bioorganic & Medicinal Chemistry, 2018, 26, 4234-4239. 3. C.J Wenthur, B. Zhou, K. Janda. Nature 2017, 548 (7668), 476-82.

Multi-functional Porus Organic Polymers (POPs): Design, Synthesis and Applications

Chetna Yadav and Jarugu Narasimha Moorthy*

Department of Chemistry, IIT Kanpur, Kanpur-208016, India Email: [email protected]

Development of porous materials that are purely inorganic (zeolites and mesoporous silica),

inorganic-organic hybrid (MOFs) and purely organic (POPs, porous organic polymers) continues to be

an exciting enterprise in view of their myriad of applications such as gas adsorption/storage,

separations, catalysis, sensing, etc. In particular, infinitely extended and hydrothermally stable

porous organic polymers (POPs) formed by covalent polymerization have engendered surge of

interest owing to their high surface areas and exotic properties.[1] POPs permit tunability of pore

size, high porosity, surface area, thermal and physiochemical stability, etc. based on a ‘bottom-up’

synthetic approach, and can be constructed in tailored fashion for various applications as stated

above by a judicious selection of organic building blocks and diligent choice of reaction for covalent

polymerization.

We have been concerned with de novo development of POPs based on organic building blocks with

certain attributes that necessarily lead, upon covalent polymerization, to porosity. POPs thus obtained

can be engineered by simple manipulations for application in gas sorption, catalysis, and dye

separations. I will present the design principles that my research has relied on to access POPs with

predefined properties for application in catalysis.[2] References

1. (a) A. G. Slater, A. I. Cooper, Science 2015, 348, aaa8075. (b) W. Zhang, B. Aguila, S. J. Ma, Mater. Chem.

A 2017, 5, 8795–8824. (c) A. Thomas, Nat. Commun. 2020, 11, 11–13. (d) G. Singh, J. Lee, A. Karakoti, R.

Bahadur, J. Yi, D. Zhao, K. Albahily, A. Vinu, Chem. Soc. Rev. 2020, 49, 4360–4404.

2. (a) C. Yadav, V. K. Maka, S. Payra, J. N. Moorthy, Journal of Catalysis 2020, 348, 61-71. (b) C. Yadav, V. K.

Maka, S. Payra, J. N. Moorthy, ACS Applied Polymer Materials 2020, 2, 3084-3093. (c) C. Yadav, A. K. Saho

o, J. N. Moorthy, 2021, Unpublished results.

Concerted or sequential? – a phase space perspective

Priyanka Pandey1, Shibabrat Naik2 and Srihari Keshavamurthy1,*

1Department of Chemistry, IIT Kanpur, Kanpur-208016, India 2School of Mathematics, University of Bristol, United Kingdom

Email: [email protected]

When reactions involve breaking and forming of multiple bonds, a key issue is to ascertain whether

the reaction proceeds through a concerted or a sequential mechanism. The ongoing debate over

concerted and sequential mechanism is not straightforward to resolve and requires a dynamical

perspective.[1,2] In this talk, I will take a model Hamiltonian for double proton transfer in order to

illustrate the role of dynamics in understanding reaction mechanism.[3] References

1. Z. Smedarchina, W. Siebrand, A. Fernández-Romas, J. Chem. Phys. 2018, 148, 102307.

2. K. Black, P. Liu, L. Xu, C. Doubleday, K. N. Houk, Proc. Natl. Acad. Sci. U.S.A 2012, 109, 12860-12865. 3. P. Pandey, S. Naik, S. Keshavamurthy, Regul. Chaotic Dyn. 2021, 26,165-182.

Diheme Enzyme MauG: Our Understanding towards Nature’s Design

Sabyasachi Sarkar and Shankar Prasad Rath*


MauG is a terminal enzyme involved in the biosynthesis of the catalytic tryptophan

tryptophenylquinone (TTQ) cofactor of methylamine dehydrogenase (MADH). Although two heme

units are physically separated in the enzyme, they share electron efficiently behaving as a single

diheme unit. A tryptophan residue, positioned midway between the heme centers, has been

postulated to act as a bridge for electronic communications. MauG-catalyzed TTQ biosynthesis is

accomplished through radical chemistry and initiated using H2O2 as the oxidant which produces bis-

Fe(IV) redox state (Figure 1). As the two hemes are physically separated by 14.5 Å, a hole-hopping

mechanism has been proposed in which the tryptophan residue reversibly oxidized and reduced

during electronic communication. These attractive features have prompted us to investigate on such

diheme enzyme and the results will be highlighted in the talk.[1-4]

Figure 1. Relative orientation of hemes and the intervening tryptophan residue in MauG (PDB ID code 3L4M), top, and formation of bis-Fe(IV) state of MauG, bottom. References

1. (a) A. Singh, F. Khan, S. P. Rath, Angew. Chem. Int. Ed. 2017, 56, 8849-8854. (b) S. Dey, D. Sil, S. P. Rath

, Angew. Chem. Int. Ed. 2016, 55, 996-1000. (c) D. Sil, S. P. Rath, Chem. Sci., 2016, 7, 1212-1223.

2. (a) A. K. Pandey, M. Usman, S. P. Rath, Chem. Commun. 2019, 55, 7926-7929. (b) A. Kumar, S. P. Rath, C

hem. Commun. 2019, 55, 1588-1591.

3. (a) A. K. Singh, M. Usman, S. Sarkar, S. P. Rath, Chem. Eur. J. 2021, 27, 0000. (b) A. Kumar, M. Usman, S.

P. Rath, Chem. Eur. J. 2021, 27, 0000. (c) A. K. Singh, S. P. Rath, Chem. Eur. J. 2020, 26, 14405-14418. (d) A. Kumar, M. Usman, E. Garribba, S. P. Rath, Chem. Eur. J. 2020, 26, 7869. (e) A. Singh, M. Usman, G.

Sciortino, E. Garribba, S. P. Rath, Chem. Eur. J. 2019, 25, 10098-10110. (f) Y. A. Pandit, S. Sanfui, S. P. Rat

h, Chem. Eur. J. 2017, 23, 13415-13422. (g) T. Guchhait, S. Sarkar, Y. A. Pandit, S. P. Rath, Chem. Eur. J.

2017, 23, 10270-10275.

4. (a) P. Mondal, S. P. Rath, Coord. Chem. Rev. 2020, 405, 213117. (b) F. S. T. Khan, S. Banerjee, D. Kumar,

S. P. Rath, Inorg. Chem. 2018, 57, 11498-11510. (c) T. Guchhait, S. Sasmal, S. P. Rath, Coord. Chem. Rev.

2017, 337, 112-144. (d) A. Dhamija, P. Mondal, B. Saha, S. P. Rath, Dalton Trans. 2020, 49, 10679-10700. (

e) D. Lai, F. S. T. Khan, S. P. Rath, Dalton Trans. 2018, 47, 14388-14401.

Synthesis of Green High Energy Density Materials

Srinivas Dharavath*


The history of high energy density materials is demonstrating the development of green high-performance

explosive material is always a challenging problem for energetic material chemists worldwide. In recent days,

the new family of green energetic materials and their salts were synthesized using five, six-membered strained

and fused rings, which are derived from commercially available starting materials. Taking this into the

consideration, herein, I intent to present the synthesis and uses of some known explosives, those of ammonium

nitrate (AN), pentaerythritol tetranitrate (PETN), trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine

(RDX), etc. This presentation also includes the newly synthesized green high energy density molecules,

energetic properties, and where these molecules will stand with the comparison of high-performance energetic

materials those of TNT, RDX, HMX, and CL-20. References

1. (a) S. Dharavath, J. Zhang, J. M. Shreeve, J. Mater. Chem. A, 2018, 6,15815–15820. (b) J, Zhang, S. Dharava

th, L. A. Mitchell, D. A. Parrish, J. M. Shreeve, J. Mater. Chem. A, 2016, 4, 16961-16967. (c) D. Kumar, G.

H. Imler, D. A. Parrish, J. M. Shreeve, Chem. Eur. J, 2017, 23, 1743-1747. (d) M. Freis, T. M. Klapötke, J. St

ierstorfer, N. Szimhardt, Inorg. Chem. 2017, 14, 7936–7947. (e) T. G. Witkowski, E. Sebastiao, B. Gabidullin,

A. Hu, F. Zhang, M. Murugesu, ACS Appl. Energy Mater. 2018, 589–593. (f) D. Kumar, L. A. Mitchell, D. A.

Parrish, J. M. Shreeve, J. Mater. Chem. A, 2016, 4, 9931-994.

Electrochemical Potential Driven Nanoscale Molecular Layers: From Surface Engineering to Molecular Electronics

Ritu Gupta, Priyajit Jash and Prakash Chandra Mondal*


Molecules have been the fascinating candidates for constructing tunable electrically conducting devices by

assembling either a single or ensemble of molecules between two electrical contacts followed by their current-

voltage (I-V) analysis are often termed ‘molecular electronics’.[1,2] Among the available techniques for surface

engineering, electrodeposition (ED) of diazonium salt on a substrate is prominent as it provides strong, stable,

reliable substrate-molecule interfaces.[3–5] Using this ED technique, we investigated the thickness, surface

roughness, surface coverage, and charge transport properties of oligo-naphthalene thin film on the different

substrates such as indium tin oxide (ITO), gold (Au), doped silicon (Si), and nickel (Ni). The thickness of the film

is varied by varying the number of electrochemical cycles, scan rates, potential window, and the concentration

of respective diazonium salt. The blocking behaviour of aryl-modified electrodes in the presence of ferrocene

and ferric ferrocyanide redox probe was studied using cyclic voltammetry. The results evidently demonstrated

that the blocking behaviour depended highly on diazonium salt and the modification procedure used. Since Ni

being ferromagnetic, we further examined its magnetic study using a Superconducting quantum interference

device (SQUID) before and after modifications.

Figure 1. Schematic illustration of the fabrication of naphthalene thin film on various substrate by electrochemical reduction method. Upon applying a reduction potential (between working and reference electrode), aryl diazonium salts are reduced forming reactive radical, which creates stable substrate-molecule interfaces.

References

1. P. R. Bueno, J. J. Davis, Chem. Soc. Rev. 2020, 49, 7505–7515.

2. P. Sachan, P. C. Mondal, Analyst 2020, 145, 1563–1582.

3. S. Bouden, J. Pinson, C. Vautrin-Ul, Electrochem. commun. 2017, 81, 120–123.

4. D. Hetemi, V. Noël, J. Pinson, Biosensors 2020, 10, 4.

5. D. D. James, A. Bayat, S. R. Smith, J. C. Lacroix, R. L. McCreery, Nanoscale Horizons 2018, 3, 45–52.

Intermixing in Ge/Si(001) Heteroepitaxial Growth: Kinetic Monte Carlo Study

Nidhi Gupta and Madhav Ranganathan*


When a thin Ge film is deposited on the Si(001) surface, it undergoes a series of morphological changes with

increasing deposition. The initially flat film spontaneously forms three dimensional islands called quantum dots.

These islands undergo shape changes and increase in size with increasing film thickness. Additionally, it is

noticed that significant amount of silicon from the substrate enters into the film in the region under the 3D

islands. It is widely believed that intermixing relieves the strain in the film. In this work we have incorporated

intermixing in the existing lattice-based kinetic Monte Carlo simulations of Ge/Si(001) heteroepitaxial growth.

Intermixing is simulated by swaps between Si and Ge, controlled by an effective barrier, that has both a surface

energy term and an elastic energy term. Our results show how the small intermixing observed at 2ML coverage

rapidly increases as we go beyond 3ML. Though intermixing is mainly favored by elastic energy, we see that

surface energy can also favor intermixing. Intermixed islands are rectangular in shape, contrary to non-

intermixed surface where islands are mostly square in shape. Islands are larger[2] in size in the intermixed surface

than non-intermixed surface. As expected intermixing increases with increasing coverage and temperature and

slows down the 3D island formation.[1]

Figure 1. Schematic diagram showing intermixing in Ge/Si system References

1. G. Capellini, M. De Seta, F. Evangelisti, Appl. Phys. Lett. 2001, 78, 303-305.

2. W. Dorsch, H. P. Strunk, H. Wawra, G. Wagner, J. Groenen, R. Carles, Appl. Phys. Lett. 1998, 72, 179-181.

Synthetic routes to nonracemic spiropiperidino indolenines, piperazines, and imidazoquinolines via SN2-type ring opening of aziridines

Navya Chauhan and Manas K. Ghorai*


Highly substituted 3-Spiropiperidino indolenines have been synthesized via Lewis acid-catalyzed SN2-type ring

opening of activated aziridines with 1H-indoles followed by Pd-catalyzed dearomative spirocyclization with

propargyl carbonates in excellent yields (up to 90%).1 The transformation comprises sequential C–C, C–N, and

C–C bond forming steps generating two stereogenic centers including an all-carbon quaternary stereocenter

to furnish the products in diastereomerically pure (dr >99:1) forms with excellent enantiomeric excess (ee up to

>99%). The SN2-type ring-opening of N-activated aziridines by anilines followed by Pd-catalyzed annulation with

propargyl carbonates gives rise to highly substituted piperazine products.2 The simple and efficient one-pot

three component synthetic route delivers piperazines with an exocyclic double bond in high yields (up to 91%)

with excellent stereoselectivity (de, ee >99%).

An efficient single-pot synthetic approach to construct 1,2,3,3a,4,5-hexahydroimidazo[1,2-a]quinolines is

described via Lewis acid-catalyzed SN2-type ring opening of activated aziridines with N-propargylanilines

followed by intramolecular cascade cyclization. The methodology expeditiously delivers the products in high

yields (up to 75% yield) with excellent diastereoselectivity (up to 94:6 dr) and enantiospecificity (up to >99% ee).3

Figure 1. Synthesis of 3-spiropiperidino indolenines, piperazines, and hexahydroimidazo[1,2-a]quinolines.

References 1. S. Pradhan, C. K. Shahi, A. Bhattacharyya, M. K. Ghorai, Chem. Commun. 2018, 54, 8583-8586. 2. N. Chauhan, S. Pradhan, M. K. Ghorai, J. Org. Chem. 2019, 84, 1757-1765. 3. S. Pradhan, N. Chauhan, C. K. Shahi, A. Bhattacharyya, M. K. Ghorai, Org. Lett. 2020, 22, 7903-7908.

The curious case of Density Functional Theory

Mainak Sadhukhan*

Department of Chemistry, IIT Kanpur, Kanpur-208016, India


In this short pedagogical talk, we will try to discuss some of the myths, facts, and challenges in modern density

functional theory for electronic structure calculations. We will discuss some of the unusual roads that this

interesting subject traversed so far. Simultaneously, some of the myths that encapsulates the subject will be

addressed. The talk will conclude with some of the challenges that we are pursuing in our laboratory at present.

Trimethylamine biodegradation by paracoccus sp. strain DMF

Shiwangi Maurya, Chetan Arya and Gurunath Ramanathan*


Paracoccus sp. strain DMF (P. DMF) is a gram-negative heterotroph that degrades dimethylformamide. This

strain was isolated from Kanpur by our group[1] and found to survive high concentrations of the toxic

anthropogenic organic solvent N, N-dimethylformamide (DMF). Previously, the strain was characterized for

growth on DMF as a sole carbon and nitrogen source. The draft of the complete genome for P. DMF on

analysis showed that a trimethylamine monooxygenase (Tmm) gene was also present in the genome.[2] Hence,

the bacteria were grown on trimethylamine as a sole carbon and nitrogen source. The current study further

elaborates the understating of metabolic and regulatory capabilities related to the utilization of unconventional

C1 compounds such as aliphatic amides and prevalent methylated amines. We also determined the biokinetic

parameters of microbial growth. Bacterial growth in trimethylamine resulted in a maximum specific growth

rate (μmax), saturation constant (Ks) and inhibition constant (Ki) as 0.9132 h-1, 229.04 mg/L and 467.29 mg/L,

respectively. The results have shown good agreement, which indicates that Paracoccus sp. strain DMF can

degrade trimethylamine up to a very high concentration. The results presented here suggest that the strain

can effectively treat waste containing trimethylamine, a factor responsible for air and water pollution.

Figure 1. TMA dependent bacterial growth and biokinetic growth parameters of P. DMF. (A) Growth of P. DMF on different initial concentrations of TMA, (--) 200 mg/L, (--) 400 mg/L, (--) 600 mg/L, 10,000 mg/L, (--)20,000 mg/L; Growth (B) Plot of specific growth rate (h-1) v/s initial substrate concentration (mg/L). (C) of P. DMF on TMA (400 mg/L) and TOC (ppm) determination; (D) Degradation of TMA along with the accumulation of DMA and ammonia, increase in the biomass and decrease in TOC with respect to time for 400 mg/L of initial DMF concentration. (-•-) TMA; (-o-) ammonia; (--) DMA; (--) control ;(--) OD555nm.

References

1. S. Swaroop, P. Sughosh, G. Ramanathan, J. Hazard. Mater. 2009. 171, 268–272. 2. A. Chetan (IIT Kanpur),. Ph.D. Thesis, Indian Institute of Technology Kanpur. 2017

Simultaneous utilization of hot holes and hot electrons in plasmon mediated amine photooxidation

Swathi Swaminathan, Vishal Govind Rao, Jitendra K. Bera and Manabendra Chandra*


Plasmon resonances represent a strong form of light-matter interaction, which enables the transfer of energy

from photons to hot charge carriers. These charge carriers are agents that aid the photochemical transformation

of molecules chemisorbed on nanoparticles. The majority of the generated charge carriers rapidly decay within

the nanostructure before they can get transferred to the adsorbed molecule or semiconductor support and thus

reduce the efficiency of charge transfer. In this work, we explore and utilize the charge separation phenomenon

within the excited gold nanoparticles for selective and high throughput catalytic conversion of amine into imine.

Under ambient laboratory conditions, these reactions were soley driven by visible light source without any

additional reagents or support. SERS and NMR techniques were employed to monitor the reaction and product

formation. Detailed mechanistic studies unequivocally show the involvement of both hot electrons and holes in

the photoactivation of adsorbates, which is quite underutilized in plasmonic photocatalysis unlike

semiconductors. The simultaneous involvement of hot electrons and hot holes in gold nanoparticle significantly

increases the reaction yield in comparison to the conventional models. Low temperatures favor highly selective

amine oxidation, thus enhancing conversion by 30-40 times relative to controls. The experimental framework

outlined in this work improves the understanding of the fundamental characteristics of LSPR-mediated

photocatalysis. References

1. S. Swaminathan, V. G. Rao, J. K. Bera, M. Chandra, Angew. Chem. Int. Ed. 2021, 60, 12532–12538.

Shedding light on transient species involved in Ru-based water oxidation catalysis

Apparao Draksharapu* and Rakesh Kumar


The efficient production of environmentally friendly fuels is one of the biggest challenges ever faced by modern

scientists.[1] Photosystem II, which contains the Mn4CaO5 cluster, can oxidize water (2H2O à O2 + 4H+ + 4e-).

The process produces H2 and O2 that are considered ideal fuels with water generation upon combustion as a

by-product.[2] Ru-based complexes are among the most explored water oxidation catalysts (WOCs) due to their

versatile redox properties and stability in water at various pH values.[3] It is proposed that high valent

intermediates are involved during the catalytic cycle (Scheme 1).[4],[5] However, direct spectroscopic evidences

for those intermediates are scarce. Therefore, our study focuses on developing new ruthenium-based WOCs,

and spectroscopic

characterization of such

transient species (i.e.,

(L)RuIV/V=O, (L)RuIII-OOH,

(L)RuIV-OO, and (L)RuIV-OO-

RuIV(L)) in water oxidation

catalysis.[6] In the present work,

four new Ru(II) complexes with

neutral amino

pyridine/benzimidazole based

ligand frameworks were

synthesized and crystallographically characterized. Their reactivities were examined with various oxidants like

ammonium ceric nitrate (CAN), NaOCl, mCPBA, etc. The preliminary results from UV-Vis absorption, resonance

Raman, EPR spectroscopies and mass spectrometry clued towards the formation of high valent intermediates.

This discussion will unveil the mechanistic aspects involved in Ruthenium-based WOCs that undoubtedly will

lead the scientific community to our present degree of understanding.

References

1. L. Hammond, Science, 1972, 177, 1088-1090. 2. L. J. Heidt, A. F. McMillan, Science, 1953, 117, 75-76. 3. R. Mathieu, M. Z. Ertem, C. G. Suriñach, X. Sala, A. Llobet, Chem. Rev., 2019, 119, 3453-3471. 4. Y. Pushkar, D. Moonshiram, V. Purohit, L. Yan, I. Alperovich, J. Am. Chem. Soc., 2014, 136, 11938-11945

. 5. J. J. Concepcion, J. W. Jurss, J. L. Templeton, T. J. Meyer, J. Am. Chem. Soc., 2008, 130, 16462-16463

. 6. D. Lebedev, Y. P. Galvan, Y. Tokimaru, A. Fedorov, N. Kaeffer, C. Copéret, Y. Pushkar, J. Am. Chem. S

oc., 2018, 140, 451-458.

Poster Presentations

Tandem Synthesis of Pyrroles from Nitroarenes and Diols Utilizing Caffeine Carbon Supported Cobalt Catalyst

Sabuj Kundu*,1 Dibyajyoti Panja,1 Anirban Sau,1 Bhuvaneshwari Balasubramaniam,2 Partha

Dhara,1 and Raju K. Gupta 2,3 1Department of Chemistry, 2Department of Chemical Engineering, 3Center for Environmental Science and

Engineering, Indian Institute of Technology Kanpur, Kanpur-208016, India Email: [email protected]

Separation and recyclability of the catalyst is one of the important issues in the sustainable catalysis. [1,2]

Nowadays, the non-precious, bio-compatible, and abundant transition metal catalysts received increasing

interest in the both academia and industry as a replacement of expensive noble metal-based systems. [3,4] In

these greener prospective, a methodology was developed for the synthesis of pyrrole scaffolds directly from

nitroarenes, employing bio-waste caffeine carbon-supported heterogeneous cobalt catalyst. A series of

caffeine carbon-supported cobalt catalysts (CoX2-CC-T) were prepared; among them, Co(OAc)2-CC-800

displayed the highest catalytic activity for this transformation. Preparative scale synthesis of pyrroles and

synthesis of anti-tubercular agent 5-(4-(1H-pyrrol-1-yl)phenyl)-1,3,4-oxadiazole-2-thiol revealed the practical

applicability of this protocol. The retention of the catalytic efficiency even after 6 times reuses showed good

stability of the catalyst, and the plausible mechanism and electronics effect were understood on the basis of

several kinetic experiments and Hammett studies.

Scheme 1. Synthesis of pyrrole from alkenyl diol. References

1. D. Formenti, C. Topf, K. Junge, F. Ragaini, M. Beller, Catal. Sci. Technol. 2016, 6, 4473.

2. C. Descorme, P. Gallezot, C. Geantet, C. George, ChemCatChem, 2012, 4, 1897.

3. C. Descorme, P. Gallezot, C. Geantet, C. George, ChemCatChem 2012, 4, 1897.

4. P. Chirik, R. Morris, Acc. Chem. Res. 2015, 48, 2495.

5. J. E. Zweig, D. E. Kim, T. R. Newhouse, Chem. Rev. 2017, 117, 11680.

Enhanced Two-Photon Activity with Extended Molecular Conjugation

Habib Ali and Debabrata Goswami*

Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, India -208016. Email: [email protected], [email protected]

The absorption of two photons of identical or different frequencies in order to excite a molecule

from its ground to its excited state is two-photon absorption. The measured laser intensity

through a sample during two-photon absorption process follows the relation: I(z,

.[1,2] Here, I0(l) is the incident Gaussian laser beam profile, z is

the propagation length in medium, β(λ) is the two-photon coefficient, which is related to the two- photon

cross-section ( ) as, and is reported in GM units that correspond to 10-

50 cm4s. We use 120 fs laser pulses at 800nm with 600mW average power from a commercial Ti:Sapphire

oscillator (Mira-900F) to excite various azepine samples dissolved in dichloromethane. The samples

were made to flow through a 1 mm closed circulating cuvette to ensure that there were no cumulative

pulse-to-pulse effects. It has been conjectured that extended molecular conjugation is more favored

towards two-photon absorption.[3] In this work we specifically show that two azepine like molecules having

cis- trans conjugated structures (Fig. 1) show a drastic change in their two-photon absorption (TPA)

characteristics. Conformer (a) in Fig. 1 has more extended conjugation as compared to conformer (b) and

find a strong correlation between the TPA signal and the molecular conjugation.

(a) (b)

Figure 1. Cis-Trans isomers of the important segments of the azepine based moieties that show drastic difference in TPA.

References

1. M. Sheik-Bahae, et al. IEEE J. Quantum Electron. 1990, 26, 760.

2. K. Makhal, P. Mathur, S. Maurya, D. Goswami, J. Appl. Phys., 2017, 121, 053103.

3. A. Nag, D. Goswami, J. Photo. Chem. Photo. Bio. A, 2009, 206, 188.

Ni(II)-Catalyzed Oxidative Deamination of Primary Amines by Water

Nilay Kumar Pal, Kuldeep Singh, Moumita Patra, Suman Yadav and Jitendra K. Bera*

Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, India -208016.


The use of water as a formal oxidant has become an emerging trend in recent era. Several challenges have to

be encountered for participating water in chemical reaction such as strong O-H bonds (enthalpy 436 kJ/mol)

that not easily breaks, high heat capacity, strong pressure dependency of the viscosity and high cohesive energy

density. Oxidation by water with the liberation of H2 helps to achieve a high atom economy and high E factor.[1]

During past few years, few catalytic system have been designed to employ water for oxidative transformations

such as conversion of alcohol to acid,[2] aldehyde−water shift reaction,[3] oxidation of olefins to carbonyl,[4] cyclic

amine to lactam,[5] homobenzylic oxygenation[6] etc. We synthesized pyridyl functionalized water soluble Ni(II)-

NHC complex with appended hydrophilic SO3- group. It offers a green and efficient protocol for catalytic

oxidative deamination of primary amines to afford aldehyde which couples with parent amine that ultimately

gives rise to homocoupled imine in aqueous medium. In presence of 2-aminothiophenol, benzothiazole

predominates over imine. Notably, this reaction strategy avoids the use of any sacrificial oxidant, in which water

plays pivotal role as an oxidant with the liberation of H2.

Scheme 1. Oxidative deamination of primary amines

References

1. R. A. Sheldon, Green Chem. 2007, 9, 1273.

2. S. Annen, T. Zweifel, F. Ricatto, H. Grützmacher, ChemCatChem 2010, 2, 1286.

3. A. S. Phearman, J. M. Moore, D. D. Bhagwandin, J. M. Goldberg, D. M. Heinekey, K. I. Goldberg, Green Chem. 2021,

23, 1609.

4. S. Tang, Y. Ben-David, D. Milstein, J. Am. Chem. Soc. 2020, 142, 5980.

5. J. R. Khusnutdinova,Y. Ben-David, D. Milstein, J. Am. Chem. Soc. 2014, 136, 2998.

6. J. B. McManus, J. D. Griffin, A. R. White, D. A. Nicewicz, J. Am. Chem. Soc. 2020, 142, 10325.

Synthesis Of Cyclic Palladium-formamidinate Complex and its Reactivity Towards Small Molecules Activation

Sadhana and Ganapathi Anantharaman* Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, India -208016.

Email: [email protected], [email protected]

The synthesis of chelated palladium formamidinate complex by deprotonation of acyclic formamidine

palladium complex in presence of base. The chelated palladium complex was found to electron rich and act as

a important precursor for preparation of various organic compounds containing hetroatomic ligands. This

complex act as a nucleophile for substrates containing electrophillic carbon atom. This nucleophillicity is due

the presence of lone pair electrons on NCN framework of amidinate unit. So, via chelated palladium complex

the activation of small molecules such as CS2, nitriles and isothiocynates were done, where these molecules

were found to inserted between Pd-N bond of complex resulted in the formation of four- membered and six-

membered palladium complexes through C-N coupling.

References

1. M. N. Kopylovich, A. J. L. Pomberio, Coord. Chem. Rev. 2011, 255, 339.

2. V. Gupta, V. Karthik, G. Ananatharaman, Dalton Trans. 2015, 44, 758.

3. C. E. Rao, S. K. Barik, K. Yuvaraj, K. Bakthavachalam, T. Roisnel, V. Dorcet, J. F. Halet, S. Ghosh, Eur. J. Inorg. Chem.

2016, 4913.

4. Y. Su, Y. Li, R. Ganguly, R. Kinjo, Angew. Chem. Int. Ed. 2018, 57, 7846.

5. Y. Su, R. Kinjio, Chem. Soc. Rev. 2019, 48, 3613.

Sensing Of Bacillis Anthracis Biomarker using Luminecent Terbium(III)-Probe

Usha Yadav and Ashis K. Patra*

Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, India -208016. Email: [email protected], [email protected]

Anthrax Bacillus is a rod shaped, gram positive and spore forming bacterium that can cause Anthrax, further

resulting in a deadly infection against living organism. Accordingly, the bacillus anthracis spore act as potential

biological warfare agent has attracted great attention recently.[1] A rapid and sensitive detection of Bacillus

anthracis is therefore crucial to minimize the probability of anthrax infection and prevent bioterrorism. The

Luminescence from Ln(III) shows intrinsic narrow f-f emission bands, long lifetime and large Stokes’ shift, which

keep off the interference from auto fluorescence from biological medium.[2] Dipicolinic acid (DPA) present in

anthrax spores (10% wt) act as unique biomarker via strong binding affinity to Tb(III) and act as efficient antenna

to populate Tb(III) excited states. This set off intense green luminescence from Tb(III) due to intraconfigurational

f®f emissions from 5D4®7FJ transitions. Herein, we have designed a coordinately unsaturated [Tb(Br-TPY-

(COOH)2(3H2O)](Cl) as a luminescent probe for efficient binding and detection of DPA2-, showing remarkable

enhancement of time-resolved luminescence and present its binding interactions, photo physical aspects and

sensor parameters.[3]

Scheme 1. Schematic design principle and proposed mechanism of the Tb-probe ‘Turn-On’ sensing for the dipicolinate biomarker via blocking the non-radiative vibrational energy transfer (VET).

References

1. K. Luan, R. Meng, C. Shan, J. Cao, J. Jia, W. Liu, Y. Tang, Analytical Chemistry 2018, 90, 3600-3607.

2. K. R. Kupcho, D. K. Stafslien, T. DeRosier, T. M. Hallis, M. S. Ozers, K. W. Vogel, J. Am. Chem. Soc. 2007, 129, 13372-

13373.

3. J. -C. G. Bünzli, C. Piguet, Chem. Soc. Rev. 2005, 34, 1048-1077.

Theoretical Studies of Hydrogen bond Dynamics and Two-Dimensional Infrared Spectroscopy of Binary Water-tert-Butyl Alcohol Mixtures

R. Malik and A. Chandra*

Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, India- 208016


Binary aqueous mixtures of tert-butyl alcohol (TBA) exhibit a large number of structural and thermodynamic

anomalies at low TBA concentration with xTBA = 0.03-0.07.[1] Further, there is a long-standing debate on

whether water molecules around hydrophilic or hydrophobic groups of an amphiphile show slow dynamics as

compared to bulk water.[2,3] In the present study, concentration induced binary aqueous mixtures of TBA are

investigated by means of molecular dynamics simulations. Two-dimensional infrared (2D IR) spectroscopic

techniques are employed to probe the hydrogen bond network fluctuations and their connection to H-bond

dynamics. Non-monotonic decrease in the number of first solvation shell water molecules is observed which is

an indication of TBA self-aggregation. We have separately probed water O-H vibrational frequency fluctuation

around hydrophilic and hydrophobic groups to study the water dynamics. There was no evidence of any unusual

dynamics in the concentration range where structural anomalies exist. On increasing TBA concentration, water

dynamics slows down monotonically. Our spectral calculations show that both the hydrophilic and hydrophobic

groups equally retard the water dynamics.

Figure 1. 2D IR metrics derived at cumulant level. (a) Central line slope for water near hydrophilic group (b) Central line slope for water near hydrophobic groups. References

1. D. Wojtkow, M. A. Czarnecki, J. Phys. Chem. A, 2005, 109, 8218.

2. G. Stirnemann, J.T. Hynes, D. Lagge, J. Phys. Chem. B, 2010, 114, 3052.

3. A. A. Bakulin, M.S. Pshenichnikov, H.J. Bakker, C. Peterson, J. Phys. Chem. A, 2011, 115, 1821.

High-Valent Cobalt Catalyzed Hydrogen Borrowing Reactions and its Mechanistic Investigations

Priyanka Chakraborty and Basker Sundararaju*

Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, India - 208 016 Email: [email protected]

Transition-metal catalyst mediated dehydrogenative reactions have evolved as an atom-economical and

selective methodology for upgrading small molecules into higher order products. In general, the initial

dehydrogenation reaction reveals a more reactive organic synthon that can undergo tandem functionalization

reactivity to construct new C-C and C-N bonds.[1] Alcohols is one of the key feed stocks for the manufacture of

basic chemicals in industries and its reactivity expands enormously on activation. Traditional methods of alcohol

oxidation often require hazardous organic or organometallic coupling partners to drive the reaction forward

which decreases the atom economy by contributing to unwanted waste products.[2] Although significant

advances using noble transition metals have been made in the past few decades, use of cost effective and

environmentally benign base metals guides this methodology towards a new dimension.[3] In this regard, we

have described the use of high valent Cp*Co(III) system in the alkylation of several carbonucleophiles with

secondary alcohols.[4],[5] DFT calculations and experimental investigations to explore the mechanistic pathway

of this redox-active and high valent Cp*Co(III) catalytic system sheds light on the involvement of a new paradigm

in the oxidative activation of alcohols unlike its high-valent noble metal analogues.[6]

Scheme 1. Cp*Co(III)-catalyzed C-C bond formations though borrowing hydrogen catalysis.

References

(1) A. Corma, J. Navas, J. M. Sabater, Chem. Rev. 2018, 118, 1410. (2) C. S. Yeung, V. M. Dong, Chem. Rev. 2011, 111, 1215. (3) (a) W. M. Akhtar, C. B. Cheong, J. R. Frost, K. E. Christensen, N. G. Stevenson, T. J. Donohoe, J. Am. Chem. Soc. 2017,

139, 2577. (b) S. Thiyagarajan, C. Gunanathan, C. J. Am. Chem. Soc. 2019, 141, 3822. (c) B. G. Reed-Berendt, K. Polidano, L. C. Morril, Org. Biomol. Chem. 2019, 17, 1595. (d) B. G. Reed-Berendt, D. E. Latham, M. B. Dambatta, L. C. Morril, ACS Cent. Sci. 2021, 7, 570.

(4) P. Chakraborty, M. K. Gangwar, E. Manoury, R. Poli, B. Sundararaju, ChemSusChem 2019, 12, 3463. (5) P. Chakraborty, N. Garg, E. Manoury, R. Poli, B. Sundararaju, ACS Catal. 2020, 10, 8023. (6) P. Chakraborty, B. Sundararaju, E. Manoury, R. Poli, ACS Catal. 2021, under revision.

A Novel Tool for Accurate and Efficient Prediction of Conformations of Biomolecules

Anji Babu Kapakayala1,2 and Nisanth N. Nair*1

1Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, India - 208 016. 2School of Pharmacy & Biomedical Sciences, Curtin University, Perth, WA, Australia.


Molecular dynamics simulations are widely used in understanding the mechanism of protein folding/unfolding, protein-drug binding/unbinding, and protein aggregation. In these simulations, it is vital to sample all relevant conformational states to accurately estimate free energetics. However, special molecular dynamics techniques like replica exchange are needed for sampling the conformational states efficiently in short simulations. Here we present a new molecular dynamics method in this direction to further improve the efficiency of the existing replica exchange methods for problems such as protein folding and ligand binding. The usefulness of the method is demonstrated by computing the folding landscape of solvated Trp-cage mini protein.

References 1. AB. Kapakayala, N. N. Nair, manuscript submitted.

2. S. Awasthi, V. Kapil, N. N. Nair, J. Comput. Chem. 2016, 37, 1413.

3. L. Wang, R. A. Friesner, B. J. Berne, J. Phys. Chem. B 2011, 115, 9431.

Synthetic Strategies for Fluorination and Trifluoromethylation of Olefins

Prabhakar Pandey and Anand Singh*

Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, India - 208 016. Email: [email protected]

Current interest in fluorine chemistry is essentially a consequence of the fact that the incorporation of fluorine

into organic molecules may profoundly change their chemical, physical, and biological properties with minimal

steric alteration, which leads to a wide range of applications in almost all aspects of the chemical industry

ranging from materials and agrochemicals to pharmaceuticals and radiotracers for positron emission

tomography (PET). A transition metal-free activation & fluorination followed by cyclization of Alkenols has been

developed using Selectfluor® reagent is reported. Here Selectfluor is used as fluorinating reagent as well

powerful oxidant that activates double bond via SET, which generates radical cation; after that, intramolecular

cyclization gives monofluoromethylated Morpholines in good-to-excellent yield (Scheme 1a). Manganese

dioxide catalyzed oxy-trifluoromethylation of styrenyl olefins and enol acetates using Langlois reagent is

achieved under oxygen/air as the oxidant. The use of convenient reagents (Langlois reagent as the “CF3”

source), oxygen as the oxidant, and mild conditions render these transformations efficient (Scheme 1b).

(a)

(b)

Scheme 1. (a) Selectfluor® mediated Oxy-fluorination of Alkenols. (b) MnO2 catalyzed aerial oxy-trifluoromethylation of Olefins

References

1. F. Guittard, E. T. de Givenchy, S. Geribaldi, A. Cambon, J. Fluorine Chem. 1999, 100, 85. (b) F. Babudri, G. M. Farinola, F. Naso, R. Ragni, Chem. Commun. 2007, 1003.

2. (a) P. Jeschke, ChemBioChem 2004, 5, 570; (b) P. Maienfisch, R. G. Hall, Chimia, 2004, 58, 93. 3. J. Zhao, M. Jiang, J.-T. Liu, Adv. Synth. Catal. 2017, 359, 1626. 4. J. Zhao, M. Jiang, J.-T. Liu, Org. Chem. Front. 2018, 5, 1155. 5. P. Panday, P. Garg, A. Singh, Asian J. Org. Chem. 2018, 7, 111.

Electronic Structure, Lattice-Dynamics, and Superconductivity in Ag-Au Alloys

Surender Singh, Subhamoy Char and DLVK Prasad*

Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, India - 208 016. Email: [email protected]

Despite the fact that monovalent noble metals defy superconductivity at atmospheric pressure, it has been

proposed recently evidence for room temperature superconductivity at ambient pressure in nanostructures of

silver particles embedded into a gold matrix.[1],[2] The origin of this emergent phenomenon in these Ag-Au

nanoalloys is unclear. The alloys may have different chemicophysical interactions [3] leading to the formation of

Cooper pair, the bosonic quasiparticle responsible for the superconductivity. To investigate this both in theory

and computations, knowledge of the alloy structure is necessary. Therefore, here we predict crystal structures

of Ag-Au alloys (3D crystals and 2D slabs) using knowledge and first principles-based crystal structure prediction

approaches. For the most thermodynamically stable and metastable structures resulted, the superconducting

transition temperatures (Tc) are estimated by carefully calculating electronic structure and electron-phonon

matrix elements. All the structures investigated are found to be metallic with a common fcc-like cuboctahedron

Ag-Au structure motif, featuring similar electronic densities of states near the Fermi surface.

The Tc are estimated within the Bardeen-Cooper-Schrieffer (BCS) formalism; it turns out that in calculations for

all the Ag-Au structures we have predicted, the transition temperatures resulted in less than one milli Kelvin.[4-6]

The BCS calculations do not indicate any sort of room temperature superconductivity as proposed in references

1 and 2, but rather our results complement the observations of near absence of superconductivity in pulsed

laser deposited Ag-Au modulated nanostructured thin films[7] and ~2 K in Ag implanted in Au thin films.[8]

Probably, as proposed[1-3] the superconductivity may be lurking in the domains of the grain-boundaries, may be

vindicated in the Fermi-surface topology. Detailed methods, calculations, and results of our investigations will

be presented.

References

1. D. K. Thapa and A. Pandey, arXiv:1807.08572, 2018, v1. 2. D. K. Thapa et al., arXiv:1807.08572, 2019, v2 and v3. 3. G. Baskaran, arXiv:1808.02005, 2018. 4. S. Singh, S. Char, and D. L. V. Prasad, arXiv:1812.09308, 2018. 5. S. Singh and D. L. V. K. Prasad, APS March Meeting, 2019, 1236. 6. D. L. V. K. Prasad and S. Singh, APS March Meeting, 2019, 1333. 7. A. Biswas, S. Parmar, A. Jana, R. J. Chaudhary, and S. Ogale, arXiv:1808.10699, 2018. 8. M. Kumar D. B. B. Singh, S. K. Sethy, S. P. Sahoo, S. Bedanta, arXiv:1906.0209, 2019.

Cu-Catalyzed Chemodivergent, Stereoselective Propargylic Dearomatization and Etherification of 2-Naphthols

V.K. Singh,* Braja Gopal Das and Sadhna Shah


Catalytic asymmetric dearomatization (CADA) reactions are acknowledged as useful strategy for constructing an optically active three-dimensional molecular architecture having contiguous stereogenic centers.[1] In this context, naphthol derivatives are anticipated to be valuable substrates because the resulting cyclohexadienone frameworks are present as the basic skeleton in various biologically active natural products and therapeutic reagents.[2] However, the dearomatization reactions of phenols/naphthols are relatively challenging due to the competitive O-alkylation (ether formation) and the Friedel- Crafts (alkylation) reaction pathways.[3]

Until now, different funtionalization of naphthol has been reported for the dearomatization of 2-naphthol are allylic, alkene, aryl, and heteroatom, etc.[4] This presentation will focus on a Cu(OTf)2 and chiral P, N, N-ligand complex catalyzed chemodivergent stereoselective propargylic dearomatization and etherification reaction of 2-naphthol derivatives. The methodology provides both the products in high yield and stereoselectivity with low catalyst loading (2 mol %) and follows a broad range of substrate scope.

Scheme 1. Chemodivergent propargylic dearomatization and etherification of 2-naphthols

References

1. (a) W.-T. Wu, L. Zhang, S.-L. You, Chem. Soc. Rev. 2016, 45, 1570-11580. (b) C. Zheng S.- L. You, Chem 2016, 1, 830-857.

2. (a) C. F. Yang, A. Stassinopoulos, I. H. Goldberg, Biochemistry 1995, 34, 2267- 2275. (b) Z. Xi, G.-S. Hwang, I. H.

Goldberg, J. L. Harris, W. T. Pennington, F. S. Fouad, G. Qabaja, J. M. Wright, G. B. Jones, Chem. Biol. 2002, 9, 925-

931.

3. (a) K. Nakajima, M. Shibata, Y. Nishibayashi, J. Am. Chem. Soc. 2015, 137, 2472-2475. (b) L. Shaoab, X.-P. Hu, Org.

Biomol. Chem. 2017,15, 9837-9844. (c) A. Z. Halimehjani, M. Khoshdoun, J. Org. Chem. 2016, 81, 5699-5704.

4. (a) Pedrazzani R. Pedrazzani, J. An, M. Monari, M. Bandini, Eur. J. Org. Chem. 2021, 1732-1736. (b) J. Hu, S. Pan, S. Zhu,

P. Yu, R. Xu, G. Zhong, X. Zeng, J. Org. Chem. 2020, 85, 7896-7904. (c) C.-J. Wang, J. Sun, W. Zhou, J. Xue, B.-T. Ren,

G.-Y. Zhang, Y.-L. Mei, Q.-H. Deng, Org. Lett. 2019, 21, 7315-7319.

Ruthenium Catalyzed Stereo- and Chemoselective Cross-Coupling reaction of Vinyl ketones and its application to Total Synthesis of

FR256523

Vimlesh Kumar and D. H. Dethe*

FR256523 is a bioactive complex natural product, belongs to family of potent macrocyclic polyene and including other two members FR252921, FR252922 were isolated from the culture broth of pseudomonas fluorescens no. 408813 and act as an immunosuppressive agent, preferably used in the treatment of allograft repulsions and autoimmune- associated diseases. Due to their complexity and architect, FR molecules have sparked great interest in synthetic community. We report here the application of ruthenium catalyzed highly stereo- and chemoselective cross-coupling reaction of vinyl ketones and acrylates for the total synthesis of FR256523. The novel and concise synthesis of triene moiety and its further exploration towards total synthesis of FR256523 natural product.

References 1. Y. Chen, G. Coussanes, C. Souris, P. Aillard, D. Kaldre, K. Runggatscher, S. Kubicek, G. Di Mauro, B. Maryasin, and N.

Maulide. J. Am. Chem. Soc. 2019, 141, 13772–13777.

2. J. Russell Falck, A. He, H. Fukui, H. Tsutsui, A. Radha. Angew. Chemie. Int. ed. 2007, 46, 4527-4529

Pd-Catalyzed Domino Cross-Coupling: Synthesis of Functionalized 4-(Arylethynyl)Coumarins

Sachchida Nand, V. N. Murty and Maddali L. N. Rao*


Coumarin scaffolds are associated with various pharmacological and photophysical properties.[1, 2] The synthesis

of 4-(arylethynyl)coumarin derivatives usually achieved through Sonogashira couplings of 4-bromo, 4-triflate,

and 4-tosyl courmarin derivatives.[3] A few cross-coupling methods using organometallic reagents involving

potassium alkynyltrifluoroborates and zinc pivalates derivatives have also been reported to synthesize the 4-

alkynyl coumarin derivatives.[4] In contrast our present study is focused on developing a domino methodology

for preparing a library of functional 4-(arylethynyl) coumarin scaffolds under Pd-catalyzed cross-coupling using

triaryl bismuth reagents.[5]

Scheme 1. Pd-catalyzed synthesis of functionalized 4-(arylethynyl)coumarins.

References

1. D. Srikrishna, C. Godugu, P. K. Dubey, Mini Rev. Med. Chem. 2018, 18, 113-141.

2. L. Taneja, A. Sharma, R. Singh, J. Lumin. 1995, 63, 203-214.

3. J. Papadopoulos, T. J. Müller, Dyes Pigm. 2019, 166, 357-366.

4. a) G. W. Kabalka, G. Dong, B. Venkataiah, Tetrahedron Lett. 2004, 45, 5139-5141. b) M. S. Hofmayer, F. H. Lutter, L.

Grokenberger, J. M. Hammann, P. Knochel, Org. Lett. 2019, 21, 36-39.

5. M. L. N. Rao, S. Nand, V. N. Murty, Asian J. Org. Chem. 2021, 10, 1822-1827.

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