Tetrahedron Letters Vol. 54, Issue 15, 2013 Contents COMMUNICATIONS Organocatalytic enantioselective transient enolate protonation in conjugate addition of thioacetic acid to a-substituted N-acryloyloxazolidinones pp 1911–1915 Rajshekhar A. Unhale, Nirmal K. Rana, Vinod K. Singh* N H HN N HN S F 3 C CF 3 R 1 N O O O R 1 N O O O AcS AcSH 1h (0.5 mol %) toluene, 0 °C up to 97% ee 1h up to 99% yield Fast thiol–maleamic methyl ester addition for facile covalent cross-linking of oligonucleotides pp 1916–1920 Liqiang Cao, Zhen Xi* Thermally driven asymmetric domino reaction catalyzed by a thermostable esterase and its variants pp 1921–1923 Reina Wada, Takashi Kumon, Robert Kourist, Hiromichi Ohta, Daisuke Uemura, Shosuke Yoshida, Kenji Miyamoto* CH 3 CO 2 Et CO 2 Et Ar CH 3 Ar H CO 2 H CH 3 CO 2 Et CO 2 H Ar CH 3 Ar H CO 2 Et Hydrolysis Thermal Hydrolysis Thermostable Esterase, 70°C, 48 h decarboxylation (S)-profens Domino reaction 1901 Contents lists available at SciVerse ScienceDirect Tetrahedron Letters journal homepage: www.elsevier.com/locate/tetlet
Transcript
Tetrahedron Letters Vol. 54, Issue 15, 2013
Contents
COMMUNICATIONS
Organocatalytic enantioselective transient enolate protonation in conjugate addition of thioacetic acid toa-substituted N-acryloyloxazolidinones
pp 1911–1915
Rajshekhar A. Unhale, Nirmal K. Rana, Vinod K. Singh*
N
HHN
N
HN S
F3C CF3
R1N
O
O
O
R1N
O
O
O
AcSAcSH
1h (0.5 mol %)toluene, 0 °C
up to 97% ee
1h
up to 99% yield
Fast thiol–maleamic methyl ester addition for facile covalent cross-linking of oligonucleotides pp 1916–1920
Liqiang Cao, Zhen Xi*
Thermally driven asymmetric domino reaction catalyzed by a thermostable esterase and its variants pp 1921–1923
A novel approach for the synthesis of hexaazaisowurtzitane derivatives pp 1931–1932
Sergey G. Il’yasov*, Maya V. Chikina
An efficient microwave-assisted enzyme-catalyzed regioselective synthesis of long chain acylated derivativesof flavonoid glycosides
pp 1933–1937
Ziaullah, H. P. Vasantha Rupasinghe*
O
O
O
OH
OH O
OHOH
OH
OH
OHOH
O
O
O
OH
OH O
OHOH
OH
OH
OHOR
+ H2O
OH
O
O
OH
OH
OH
OH
OH
OH
O
OH
O
O
OH
OH
OH
OR
OH
OH
O+ H2O
i, iii, ii
Our present investigation provides a facile, efficient, and economical method of microwave-assisted biocatalytic regioselective synthesis of long chain acylated derivatives ofisoquercitrin and phloridzin. (i) Acetone, 3 Å molecular sieves, Novozyme 435®, 45 �C; (ii) R = Oleic, Stearic, Linoleic, Linolenic, Eicosapentaenoic (EPA), Docosahexaenoic Acids(DHA), or their corresponding esters.
2,5-Bis-(sulfonyl)pyrazines as unprecedented building blocks and their SNAr reactions pp 1938–1942
Jie Jack Li, Wei Meng, Shung Wu, Yong-Jin Wu, Jason Guernon, Martin P. Allen, Michael M. Miller*, Peter T. Cheng,Bang-chi Chen
N
NO2S
SO2
RR
N
N
SO2
R
X
R = Me, tBu, PhMe
X = O, S, NH
Y
N
N
SO2
R
NHN
HNBoc
Boc
N
N
SO2
R
N
N
N
SO2
RCO2Et
NMe
CO2Et
Hookerolides A–D, the first naturally occurring C17-pseudoguaianolides from Inula hookeri pp 1943–1946
Xiang-Rong Cheng, Jie Ren, Chun-Hui Wang, Bin Guan, Jiang-Jiang Qin, Shi-Kai Yan, Hui-Zi Jin*, Wei-Dong Zhang*
+0.078
−0.014
−0.030−0.058
−0.041
−0.068
−0.009
−0.025
−0.034
−0.012
−0.008
−0.043
−0.005 −0.054
−0.071
O O
O
O
H
OMTPA
O
13
16
17
−0.116-10
-5
0
5
10
15
20
200 250 300 350 400
CD [mdeg]
Wavelength [nm]
Hookerolide A
1R
16R
Samarium (II) iodide-induced intermolecular coupling of a,b-unsaturated esters with ketones: reactions of methylpropiolate and ethyl buta-2,3-dienoate with cyclohexanone and its application to synthesis of a terpene carboxylic acid
Cu-catalyzed decarboxylative coupling of propiolic acids with boronic acids pp 1951–1955
Leilei Shi, Wei Jia, Xun Li*, Ning Jiao*
BOH
OH
R1 R2
COOHR2
R1CuCl2.2H2O, BQ, Et3N,Pyridine
DCM, RT+
A mild procedure of Cu-catalyzed decarboxylative cross-coupling of aryl- and alkynyl-boronic acids for construction of unsymmetrical substitutedalkynes has been developed. The usage of inexpensive copper chloride as catalyst, and employing stable alkynl carboxylic acids and boronic acids as thesubstrates under oxidative conditions for sp–sp2 coupling, make this method very easy to operate.
Organocatalytic enantioselective conjugate addition of 2-nitrocyclohexanone to acrylaldehyde: a concisetwo-step synthesis of chiral building block 1-azaspiro[4.5]decan-6-one
pp 1956–1959
Xiao-Hua Ding, Wei-Chen Cui, Xiang Li, Xuan Ju, Dan Liu, Shaozhong Wang, Zhu-Jun Yao*
NO2
O
+
O
H
HN
O(1S)-azaspiro[4.5]decan-6-one89% ee; 84% ee (gram-scale)
2 Steps
A three-component synthesis of benzochromenodiazocines and chromenopyridines pp 1960–1962
A one-pot, pseudo four-component synthesis of novel benzopyrano[2,3-b]pyridines under solvent-free conditions pp 1963–1966
Abolfazl Olyaei*, Mohsen Vaziri, Reza Razeghi
+CHO
Z+
CN
CN2
OHsolvent-free 110 oC
10 examples
YX
Z
W
X, Y, Z, W = H or OH
O N
NH2CN
NH2
ZHO
W
O N
NH2CN
NH2
Z
OHHO
or
Stereoselective synthesis of 1,2,3-triazolyl-functionalized isoxazolidines, via two consecutive 1,3-dipolarcycloadditions, as precursors of unnatural amino acids
A direct route to 2,2,5-trisubstituted pyrrolidines of relevance to kaitocephalin pp 1987–1990
Nandkishkor Chandan, Mark G. Moloney*
Syntheses of p-terphenyls and 11,12-dihydroindeno[2,1-a]fluorene by one-pot benzannulation of Diels–Alderreactions of trans-1,2-dichloroethene and dienes
Large and selective electrochemical response to fluoride by a tetrathiafulvalene-based sensor pp 1998–2000
Jing Xiong, Long Cui, Wei Liu, Jonathon E. Beves, Yu-Yang Li, Jing-Lin Zuo*
A new dual electro-optical fluoride sensor based on tetrathiafulvalene (TTF) generates the largest known electrochemical response to fluoride ions, a DE1/2 ofalmost 400 mV. The sensor is highly selective for fluoride over other anions, and displays ‘naked eye’ optical detection.
A practical one-pot procedure for the synthesis of N–H isoquinolones pp 2001–2005
Shaonan Lu, Yingfu Lin, Hongban Zhong, Kang Zhao, Jianhui Huang*
2. NaH, 120 oC
NH
OOR1
R2R3
N
O
R2R3
Ar Ar
1. Pd(OAc)2 (10 mol%), NaI.2H2ONaOAc, DMF, 120 oC
H
17 examples yields up to 99%
Fast, solvent-free asymmetric alkynylation of prochiral sp3 C–H bonds in a ball mill for the preparation ofoptically active tetrahydroisoquinoline derivatives
*Corresponding authorSupplementary data available via SciVerse ScienceDirect
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