Enantioconvergent Synthesis of Functionalized γ-Butyrolactones via (3 + 2)-Annulation
作者:C. Guy Goodman、Morgan M. Walker、Jeffrey S. Johnson
DOI:10.1021/ja511701j
日期:2015.1.14
A dynamic kineticresolution of β-halo α-keto esters in an asymmetric homoenolate reaction is described. A chiral N-hetereocyclic carbene catalyzes the a3 → d3-umpolung addition of α,β-enals to racemic α-keto esters, forming γ-butyrolactones with threecontiguousstereocenters. The addition occurs with high regio-, diastereo-, and enantiocontrol. This methodology constitutes an intermolecular DKR process
Nickel(II)-Catalyzed Diastereo- and Enantioselective [3+2] Cycloaddition of α-Ketoesters with 2-Nitrovinylindoles and 2-Nitrovinylpyrroles
作者:Wu-Lin Yang、Zhong-Tao Sun、Hao Sun、Wei-Ping Deng
DOI:10.1002/cjoc.201800572
日期:2019.3
The catalyticasymmetric [3+2] cycloaddition of α‐ketoesters with 2‐nitrovinylindoles and 2‐nitrovinyl‐ pyrroles has been established. This strategy allowed the construction of structurally diverse pyrrolo[1,2‐a]indoles bearing three contiguous stereocenters in generally high yields and good to excellent stereoselectivities (up to 98% yield, > 98 : 2 dr, 99% ee). The efficient synthesis of tetracyclic
建立了α-酮酸酯与2-硝基乙烯基吲哚和2-硝基乙烯基吡咯的催化不对称[3 + 2]环加成反应。该策略允许构建具有三个连续立体中心的结构多样的吡咯并[1,2- a ]吲哚,且通常具有高产率和良好至优异的立体选择性(产率高达98%,> 98:2 dr,99%ee)。通过环加合物的衍生化有效合成四环精神化合物类似物显示了该策略的巨大合成潜力。