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Total Synthesis of (+)-Corymine 2020.9.12. Literature Seminar B4 Hibiki Asai
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  • Total Synthesis of(+)-Corymine

    2020.9.12. Literature SeminarB4 Hibiki Asai

  • 1. Introduction

    2. Total synthesis of (-)-Vincorine(by MacMillan Group)

    3. Total synthesis of (+)-Corymine(by Li Group)

    Contents

    2

  • Akuammiline Alkaloids

    1) Zi, W.; Xie, W.; Ma, D. J. Am. Chem. Soc. 2012, 134, 4037. 2) Eckermann, R.; Gaich, T. Synthesis 2013, 45, 2813.

    3

    32N

    N21

    16

    OMe

    CO2MeHH

    • migration of C3-N bond to C2-N• strained 7-membered azepanyl ring

    A

    B

    D

    E

    C

    32

    16N

    CO2Me

    NC D

    EB

    A

    akuammilinealkaloids

    HN

    N

    OMe

    CO2MeHH

    Boc Cl(1) TMSOTf, 2,6-lutidine CH2Cl2(2) K2CO3, KI MeCN, 60 °Cconstruction of D-ring

    (3) HCHO, NaBH3CN MeCN, AcOH

    (-)-vincorine

    by Ma Group

  • Vincorine and Corymine

    1) Mokrý,́J.;Dub́ravkova,́L.;Šefcǒvic,̌P.Experientia1962,18, 564. 2) Kiang, A. K.; Smith, G. F. Proc. Chem. Soc. 1962, 298.3) Zhang, M.; Huang, X.; Shen, L.; Qin, Y. J. Am. Chem. Soc. 2009, 131, 6013.4) Zi, W.; Xie, W.; Ma, D. J. Am. Chem. Soc. 2012, 134, 4037.5) Horning, B. D.; MacMillan, D. W. C. J. Am. Chem. Soc. 2013, 135, 6442.6) Zhang, B.; Wang, X.; Cheng, C.; Sun, D.; Li, C. Angew. Chem., Int. Ed. 2017, 56, 74847) Zhang, B.; Wang, X.; Li, C. J. Am. Chem. Soc. 2020, 142, 3269.8) Eckermann, R.; Gaich, T. Synthesis 2013, 45, 2813.

    4

    32N

    N

    O CO2Me

    OH

    16

    H

    32N

    N

    16

    OMe

    CO2MeHH

    (-)-vincorine (+)-corymineVinca minor (1962) 1) Hunteria corymbosa (1962) 2)Isolation:

    Structual features: pentacyclic caged structurestrained 7-membered azepanyl ring

    hexacyclic caged structurestrained 7-membeed azepanyl ringC16 extra carbon

    Total synthesis: Qin (2009 (35 steps, racemic)) 3)Ma (2012 (18 steps, enantioselective)) 4)MacMillan (2013 (9 steps, enantioselective)) 5)

    Li (2017 (21 steps, racemic), 2020 (11 steps, 99% ee)) 6) 7)

    A A

    B B

    D DE E

    C C

  • Introduction of Prof. MacMillan and Li

    1) https://macmillan.princeton.edu2) http://www.fluorinelab.ac.cn/ketizu.jsp?name=李超忠 5

    Prof. David W. C. MacMillan

    1991 B.S. @ University of Glasgow1996 Ph.D @ the University of California, Irvine (Prof. Larry E. Overman)1996- Postdoctral fellow

    @ Harvard University (Prof.David A. Evans) 1998- @ the University of California, Berkeley2000- @ the California Institute of Technology2004- Professor @ the California Institute of Technology2006- Professor @ Princeton University2011- Distinguished professor @ Princeton University

    Research topic: photoredox, organocatalysis, total synthesis

    Prof. Chaozhong Li

    1988 B.S @ University of Science and Technology of China1993 Ph.D @ Shanghai Institute of Organic Chemistry1993- Assistant Researcher @ Shanghai Institute of Organic Chemistry1994- Postdoctral fellow @ Iowa State University1999- Associate professor @ Shanghai Institute of Organic Chemistry2000- Professor @ Shanghai Institute of Organic Chemistry

    Research topic: free radical chemistry, organofluorine chemistry,organometallic chemistry, natural product synthesis

  • Retrosynthetic Analysis

    1) Horning, B. D.; MacMillan, D. W. C. J. Am. Chem. Soc. 2013, 135, 6442.2) Zhang, B.; Wang, X.; Li, C. J. Am. Chem. Soc. 2020, 142, 3269. 6

    3N15

    N 20

    O CO2MeOH

    16

    H

    N15

    N 20

    OMe

    CO2MeH

    N

    OMe

    NH

    BocN

    N

    OMe

    CO2MeHX

    H

    3N

    NO

    CO2Me16CO2Me

    Br

    HN NBr

    CO2MeCO2Me

    O R

    HNN

    R

    Br

    7-memberedcyclization

    ; Hemiacetalization7-memberedcyclization

    asymmetricalkylation

    asymmetricDiels-Aider reaction

    (-)-vincorine

    (+)-corymine

    MeO2C Oby MacMillan

    by Li

    D

    E

    D

    E

    CC

    C

    C

    E

    E

    Y

  • 1. Introduction

    2. Total synthesis of (-)-Vincorine(by MacMillan Group)

    3. Total synthesis of (+)-Corymine(by Li Group)

    Contents

    7

  • Synthesis of Diene

    1) Horning, B. D.; MacMillan, D. W. C. J. Am. Chem. Soc. 2013, 135, 6442.2) Biscoe, M. R.; Fros, B. P.; Buchwald, S. L. J. Am. Chem. Soc. 2008, 130, 6686. 8

    HN

    OMe

    NH

    Boc

    commercially available

    NaH, DMF, 0 °C; MeI

    N

    OMe

    NH

    Boc

    n-BuLi1,2-dimethoxyethane, -40°C

    ; ZnCl2, -78 °C to rt I

    N

    OMe

    NH

    Boc

    PdIINH2

    Cl

    XPhos precatalyst

    Negishi coupling

    ; XPhos precatalyst,N

    OMe

    NH

    BocZnCl

    ortho metalation

    96%

    PCy

    CyAr

    Ar =

    i-Pr

    i-Pr

    i-Pr

    71%

  • Diels-Alder/Cyclization Cascade (I)

    1) Northrup, A. B.; MacMillan, D. W. C. J. Am. Chem. Soc. 2002, 124, 2458.2) Horning, B. D.; MacMillan, D. W. C. J. Am. Chem. Soc. 2013, 135, 6442. 9

    N

    OMe

    NH

    BocMeO2C O

    catalyst (20 mol%)MeCN, -20 °C

    N

    OMeHN

    CO2Me

    CHO

    Boc

    N

    HN

    OMe

    CO2MeHCHO

    H

    Boc

    N

    N

    OMe

    CO2MeHCHO

    H

    Boc

    N

    NHPh

    Me

    Me

    MeO

    catalyst

    Diels-Alderreaction

    +H+

    -H+MeO2C O

    70% yieled, 95% ee

    E

    E

    E

    C

    catalyst HBF4

  • Diels-Alder/Cyclization Cascade (II)

    1) Northrup, A. B.; MacMillan, D. W. C. J. Am. Chem. Soc. 2002, 124, 2458.2) Horning, B. D.; MacMillan, D. W. C. J. Am. Chem. Soc. 2013, 135, 6442.

    10

    N

    NH Me

    MeO

    MeO2C

    N

    N Me

    MeO

    CO2Me

    N

    NH

    H Me

    MeO

    MeO2C OH H

    Diels-Alder

    N

    OMeHN

    CO2Me

    Boc

    NNMe

    O

    Me

    N

    HNBoc

    OMe

    N

    OMeHN

    CO2Me

    CHO

    Boc

    N

    N

    OMe

    CO2MeHCHO

    H

    Boc

    +H2O-H+

    Me Me Me

    Me

    Ph

    EZ

    largeallylic strain

    smallallylic strain

    electrophilic

    nucleophilic

    H

    Ph Ph Ph

  • Enantioselectivity of Diels-Alder

    1) Northrup, A. B.; MacMillan, D. W. C. J. Am. Chem. Soc. 2002, 124, 2458.2) Horning, B. D.; MacMillan, D. W. C. J. Am. Chem. Soc. 2013, 135, 6442.

    11

    N

    HN BocOMe

    CO2Me

    N

    OMe

    HNBoc

    N

    CO2Me

    NMe

    OMeMe

    PhN

    OMe

    HNBoc

    N

    CO2Me

    NMe

    OMeMe

    Ph

    N

    NMe O

    Me

    Ph

    Me

    N

    OMeHN

    CO2Me

    CHO

    Boc

    ‡ ‡

    hydrolysis

  • Synthesis of Radical Cyclization Precursor

    1) Horning, B. D.; MacMillan, D. W. C. J. Am. Chem. Soc. 2013, 135, 6442.12

    N

    N

    OMe

    CO2MeHCHO

    H

    Boc

    N

    N

    OMe

    CO2MeHCO2H

    H

    Boc

    N

    N

    OMe

    CO2MeHCOTePh

    H

    Boc

    N

    N

    OMe

    CO2MeHCOTePh

    H

    NaClO2,THF/t-BuOH/H2O, 0 °C

    Cl O

    O

    N-methylmorpholineTHF, -10 °C;

    (PhTe)2, NaBH4THF/MeOH, -10 °C

    (1) CF3CO2H

    (2)O

    St-Bu

    NaBH(OAc)3CH2Cl2

    acyl telluridation

    N

    N

    OMe

    CO2MeH

    H

    Boc

    O

    O

    O

    O

    96%

    87%

    65% (2 steps)

    St-Bu

  • Radical Cyclization (I)

    1) Horning, B. D.; MacMillan, D. W. C. J. Am. Chem. Soc. 2013, 135, 6442. 2) Chen, C.; Crich, D.; Papadatos, A. J. Am. Chem. Soc. 1992, 114, 8313. 13

    N

    N

    OMe

    CO2MeH

    H N

    N C

    OMe

    CO2MeHH

    X

    O radical cyclization

    X condition solvent yield[%]

    SePh

    TePh

    120 °C, 5 hBu6Sn2, hν (Hg lamp)

    200 °C, 10 h

    St-Bu

    chlorobenzene(5 mM)

    1,2-dichlorobenzene(0.5 mM)

    conversion[%]

    85

    100

    17a

    51b

    a Yield based on 1H NMR analysis. b Isolated yield.

    D

  • Radical Cyclization (II)

    1) Horning, B. D.; MacMillan, D. W. C. J. Am. Chem. Soc. 2013, 135, 6442.2) Chen, C.; Crich, D.; Papadatos, A. J. Am. Chem. Soc. 1992, 114, 8313. 14

    N

    N

    OMe

    CO2MeH

    H

    N

    N C

    OMe

    CO2MeHH

    TePh

    O

    St-Bu

    N

    N

    OMe

    CO2MeH

    H

    O

    St-Bu

    N

    N

    OMe

    CO2MeH

    St-Bu

    -t-BuS

    -CO

    H

    -PhTe

    Δ

    7-exo

  • Total Synthesis of (-)-Vincorine

    1) Horning, B. D.; MacMillan, D. W. C. J. Am. Chem. Soc. 2013, 135, 6442. 15

    N

    N

    N C

    OMe

    CO2MeHH

    Pd/C, H2THF, -15 °C

    N

    N

    OMe

    CO2MeHH

    hydrgenetion fromless hindered face

    80% (-)-vincorine

    H H

    H H

    H H

    H H

    MeO2C

    H

    CN C

    MeO2C

    boat skewed-boat

  • Short Summary

    1) Horning, B. D.; MacMillan, D. W. C. J. Am. Chem. Soc. 2013, 135, 6442.16

    N

    N

    OMe

    CO2MeHH

    (-)-vincorine

    N

    OMe

    NH

    Boc N

    N

    OMe

    CO2MeHCHO

    H

    Boc

    N

    N

    OMe

    CO2MeHCOTePh

    H

    2 steps fromcommercially available

    compound

    asymmetricDiels-Alder reaction

    MeO2C O

    radical cyclization

    St-Bu

    • 9 steps syntesis• asymmetric Diels-Alder reaction• radical cyclization using acyl telluride

    C

    D

    E

  • 1. Introduction

    2. Total synthesis of (-)-Vincorine(by MacMillan Group)

    3. Total synthesis of (+)-Corymine(by Li Group)

    Contents

    17

  • Retrosynthesis

    1) Zhang, B.; Wang, X.; Li, C. J. Am. Chem. Soc. 2020, 142, 3269. 18

    N

    N

    O CO2Me

    OHH

    N

    NO

    CO2MeCO2Me

    N

    NO

    CO2MeCO2Me

    Br

    N NBr

    CO2MeCO2Me

    RHN N

    BrO

    Br

    R

    hemiacetalization 7-menberedcyclization

    constructionof C, E-rings

    chain extension;asymmetric addition

    C

    E

    (+)-corymine

    D

    O OEtEtO

  • Synthesis of 3-bromooxindole

    1) Zhang, B.; Wang, X.; Li, C. J. Am. Chem. Soc. 2020, 142, 3269. 19

    HNNH

    Ns HN NNs

    Br

    BrBr

    NBS, H2Ot-BuOH/THF

    commercially available

    K2CO3DMF

    HN N

    O

    Br

    Ns

    Br95%

    (2 steps)

    HNN

    Ns

    Br

    OH

    Br

  • Cu-Catalyzed Enantioselective Alkylation

    1) Zhang, B.; Wang, X.; Li, C. J. Am. Chem. Soc. 2020, 142, 3269.2) Ma, S.; Han, X.; Krishnan, S.; Virgil, S. C.; Stolz, B. M. Angew. Chem. , Int. Ed. 2009. 48, 8037. 20

    HN NBr

    CO2MeCO2Me

    O NsMeO2C CO2Me

    [Cu], i-Pr2NEt, MS3ACH2Cl2, -20 °C

    CuIIN

    N

    O

    O

    Ph

    Ph

    [Cu]

    asymmetric alkylation

    HN NBrO

    Br

    Ns

    > 99% eerecrystallization, 90%

    2 SbF6

    65% yield, 91% ee

    2

  • Proposed Mechanism ofCu-Catalyzed Alkylation (I)

    1) Zhang, B.; Wang, X.; Li, C. J. Am. Chem. Soc. 2020, 142, 3269.2) Ma, S.; Han, X.; Krishnan, S.; Virgil, S. C.; Stolz, B. M. Angew. Chem. , Int. Ed. 2009. 48, 8037.3) D. M. Barnes, J. Ji, M. G. Fickes, M. A. Fitzgerald, S. A. King, H. E. Morton, F. A. Plagge, M. Preskill, S. H. Wagaw, S. J. Wittenberger, J. Zhang, J.

    Am. Chem. Soc. 2002, 124, 13097 21

    N

    CuII

    N

    OO

    Ph Ph

    N

    CuIIN

    OO

    Ph PhO O

    MeO OMe

    N

    CuIIN

    OO

    Ph PhO O

    MeO OMe

    +H+

    -H+

    N NBrO

    Br

    Ns

    H

    NEt(i-Pr)2

    H

    i-Pr2EtNN R

    O

    Br=R

    NO

    R+H+

    -H+ -Br-

    22

  • Proposed Mechanism ofCu-Catalyzed Alkylation (II)

    1) Zhang, B.; Wang, X.; Li, C. J. Am. Chem. Soc. 2020, 142, 3269.2) Ma, S.; Han, X.; Krishnan, S.; Virgil, S. C.; Stolz, B. M. Angew. Chem. , Int. Ed. 2009. 48, 8037.3) D. M. Barnes, J. Ji, M. G. Fickes, M. A. Fitzgerald, S. A. King, H. E. Morton, F. A. Plagge, M. Preskill, S. H. Wagaw, S. J. Wittenberger, J. Zhang, J.

    Am. Chem. Soc. 2002, 124, 13097 22

    CuII

    O O

    NR OMe

    CO2Me

    NCuIIN

    OO

    Ph Ph

    CuII

    O O

    MeO OMeH

    CuII

    O O

    MeO OMe

    MeO2C CO2Me

    NO

    R

    HNO

    RBr

    -HBr

    -H+

    iPr2EtN H

    HNO

    R

    CO2MeCO2Me

    CuII

    O O

    MeO OMe

    N

    O

    R

    N N N N

    NNNN

    2

    2

  • Proposed Mechanism ofCu-Catalyzed Alkylation (III)

    1) Zhang, B.; Wang, X.; Li, C. J. Am. Chem. Soc. 2020, 142, 3269.2) Ma, S.; Han, X.; Krishnan, S.; Virgil, S. C.; Stolz, B. M. Angew. Chem. , Int. Ed. 2009. 48, 8037.3) D. M. Barnes, J. Ji, M. G. Fickes, M. A. Fitzgerald, S. A. King, H. E. Morton, F. A. Plagge, M. Preskill, S. H. Wagaw, S. J. Wittenberger, J. Zhang, J.

    Am. Chem. Soc. 2002, 124, 13097 23

    HN

    R

    O

    N

    CuIIN

    OO

    Ph PhO O

    MeO OMe

    N

    CuIIN

    OO

    Ph PhO O

    MeO OMe

    stericrepulsion

    HN

    R

    O

    CuII

    O O

    MeO OMe

    N

    O

    R

    CuII

    O O

    NR OMe

    CO2Me

    ‡ ‡

    N N N N

  • Installation of Alkyl Chain

    1) Zhang, B.; Wang, X.; Li, C. J. Am. Chem. Soc. 2020, 142, 3269. 24

    HN NBr

    CO2MeCO2Me

    O Ns alkyllithiumGrignard reagent

    N

    3

    NBr

    OEtEtO

    CO2MeCO2Me

    Ns

    N NBr

    CO2MeCO2Me

    OTf Ns

    Tf2O2,6-lutidine

    CH2Cl2, -78 °C

    EtO

    OEt

    B

    Pd(PPh3)4, (o-tolyl)3Pborane A, K2CO3

    THF, 75 °C

    borane A

    Suzuki coupling

    N3

    NBr

    O OEtEtO

    CO2MeCO2Me

    Ns

    MnO2CH2Cl2

    oxidation of C3

    54%, 2 steps(73% brsm, 2 steps)

    65%

  • Attempted Construction of C,E-Rings

    1) Zhang, B.; Wang, X.; Li, C. J. Am. Chem. Soc. 2020, 142, 3269. 25

    N N

    O OEtEtO

    CO2Me

    CO2Me

    Ns p-thiocresolK2CO3, MeCN

    N

    CO2MeCO2Me

    NBr

    O

    undesired

    N N

    O OEtEtO

    CO2Me

    CO2Me

    N-deprotection

    BrBr

    N N

    OEtO

    CO2Me

    CO2MeBr

    E1cBeliminiation

    8-endo

    -EtOHHN

    NO

    CO2MeCO2Me

    Br

    desired

    C

    OEtOEt

    5-exo

    H

    82%

  • Construction of C,E-Rings (II)

    1) Zhang, B.; Wang, X.; Li, C. J. Am. Chem. Soc. 2020, 142, 3269. 26

    N N

    O OEtEtO

    CO2Me

    CO2Me

    NsN

    O

    CO2MeCO2Me

    OEt

    N

    Br

    Ns

    HN

    NO

    CO2MeCO2Me

    Br

    OEt

    desired

    ; p-thiocresol

    5-exo

    Br

    EtONaTHF N N

    OEtO

    CO2Me

    CO2Me

    Ns

    Br

    E

    NO

    CO2MeCO2Me

    OEt

    N

    Br

    E

    C

    E1cB 6-endo

    66%

  • Formation of 7-membered Ring (I)

    1) Zhang, B.; Wang, X.; Li, C. J. Am. Chem. Soc. 2020, 142, 3269.27

    HN

    NO

    CO2MeCO2Me

    Br

    OEt N

    NO

    CO2MeCO2Me

    Br

    OEt

    N

    NO

    CO2MeCO2Me

    Br

    N

    N

    OCO2Me

    CO2Me

    ; TMSOTf

    Bu3SnH or (TMS)3SiH-mediated,photoredox-catalyzed,

    or cobalt-catalyzedradical cyclization

    Me3O•BF4 CH2Cl2

    D

    72%

  • Formation of 7-membered Ring (II)

    1) Zhang, B.; Wang, X.; Li, C. J. Am. Chem. Soc. 2020, 142, 3269.2) Sole, D.; Cancho, Y.; Llebaria, A.; Moreto, J. M.; Delgado, A. J. Am. Chem. Soc. 1994. 116, 12133.3) Nicolaou, K. C.; Roecker, A. J.; Follmann, M.; Baati, R. Angew. Chem., Int. Ed. 2002, 41, 2107.4) Okamura, H.; Mori, N.; Watanabe, H; Takikawa, H. Tetraherdon Lett. 2018, 59, 4397.

    28

    N

    NO

    CO2MeCO2Me

    Br

    N

    N

    OCO2Me

    CO2Me

    N

    N

    OCO2Me

    CO2Mereductive Heck coupling

    undesired

    desired

    Pd(OAc)2 (20 mol%)K2CO3, Bu4NCl, HCO2Na

    DMF, 80 °C

    Ni(cod)2 (6 eq.)NaI (10 eq.), Mg(OTf)2 (2 eq.)

    DMF, 80 °C

    Ni-mediated cyclyzation

    Ni0

    Ni0(cod)2

    D

    50%

    46%

  • Ni(cod)2-Mediated Cyclization

    1) Zhang, B.; Wang, X.; Li, C. J. Am. Chem. Soc. 2020, 142, 3269.2) Sole, D.; Cancho, Y.; Llebaria, A.; Moreto, J. M.; Delgado, A. J. Am. Chem. Soc. 1994. 116, 12133.3) Nicolaou, K. C.; Roecker, A. J.; Follmann, M.; Baati, R. Angew. Chem., Int. Ed. 2002, 41, 2107.4) Okamura, H.; Mori, N.; Watanabe, H; Takikawa, H. Tetraherdon Lett. 2018, 59, 4397.

    29

    N

    NO

    CO2MeCO2Me

    Br

    N

    N

    OCO2Me

    CO2Me

    N

    NO

    CO2MeCO2Me

    NiIILnX

    oxidativeaddition

    activationof enone

    N

    NO

    CO2MeCO2Me

    NiIILnX

    transferinsertion

    work up

    X = Br or I or OTfNi0Ln MgIIX

    X

    N

    NO

    CO2MeCO2Me

    NiIILnXMgIIX

    MgIIX

    eliminationof NiII

    N

    NO

    CO2MeCO2Me

    MgIIX

    -NiIILnX2

    X

    X

  • Total Synthesis of (+)-Corimine

    1) Zhang, B.; Wang, X.; Li, C. J. Am. Chem. Soc. 2020, 142, 3269. 30

    N

    N

    OCO2Me

    CO2Me

    N

    N

    HO CO2MeCO2Me

    from less hindered face

    lactonization

    ; i-Bu2AlH-78 °C

    from lesshindered face

    (+)-coryimne

    KBH4MeOH

    Cs2CO3toluene, 100 °C

    KBH4 95%

    82%

    N

    N

    O CO2Me

    O

    N

    N

    O CO2Me

    OH2

    H BH3

    N

    N

    O CO2Me

    OHH

  • Extension to Other Family

    1) Zhang, B.; Wang, X.; Li, C. J. Am. Chem. Soc. 2020, 142, 3269.31

    OHN

    NO

    CO2MeCO2Me

    N

    N

    HO CO2MeCO2Me

    N

    N

    HO CO2MeH

    (-)-deformylcorymine

    (1) CS2, NaH, MeI THF, 0 °C to rt(2) (TMS)3SiH, AIBN benzene, 80 °C

    N

    N

    CO2MeH

    (-)-10-demethoxyvincorine

    i-Bu2AlHtoluene, -78 °C

    N

    N

    CO2Me

    OH

    HO

    N

    N

    CO2Me

    OAc

    H

    Ac2O/Py; CF3CO2H

    (-)-3-epi-dihydrocormine-17-acetate

    N

    N

    OCO2Me

    H

    N

    N

    CO2MeH

    (1) SmI2 THF/MeOH(2) BF3•OEt2, Et3SiH CH2Cl2

    (-)-2(S)-cathafoline

    LiCl, DMF, 120 °C

    KBH4MeOH

    LiClDMF, 120 °C

    95%

    71%

    82%70%

    80%

    77%

    62%

  • Short Summary

    1) Zhang, B.; Wang, X.; Li, C. J. Am. Chem. Soc. 2020, 142, 3269. 32

    N

    N

    O CO2Me

    OHH

    N

    NO

    CO2MeCO2Me

    N

    NO

    CO2MeCO2Me

    Br

    N N

    O OEtEtO

    CO2Me

    CO2Me

    NsHN N

    CO2Me

    CO2Me

    O NsHN N

    O

    Br

    Ns

    hemiacetalization Ni-mediatedcyclization

    nucleophiliccyclizatoin

    Suzukicouplingasymmetricaddition

    • 11 steps synthesis• Cu-catalyzed asymmetric addition• construction of C, E-rings on one step• Ni-mediated 7-endo cyclization

    Br Br Br

    2 steps fromcommercially available

    compound

    (+)-corymine

    CD

    E

  • N

    N

    O CO2Me

    OHH

    N

    N

    OMe

    CO2MeHH

    N

    OMe

    NH

    Boc

    N

    N

    OMe

    CO2MeHCOTePh

    H

    StBu

    N

    NO

    CO2MeCO2Me

    Br

    HN N

    CO2Me

    CO2Me

    O Ns

    HNN

    Ns

    Br

    radicalcyclization

    Ni-mediatedcyclization

    ; Hemiacetalization

    asymmetricalkylationasymmetric

    Diels-Aider reaction

    (-)-vincorine (+)-corymine

    achiral indol derivative

    N

    N

    OMe

    CO2MeHCHO

    H

    Boc

    Br

    by MacMillan by Li

    CDE

    CD

    E

    Summary

    1) Horning, B. D.; MacMillan, D. W. C. J. Am. Chem. Soc. 2013, 135, 6442.2) Zhang, B.; Wang, X.; Li, C. J. Am. Chem. Soc. 2020, 142, 3269.

    33


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