Catalytic asymmetric dipolar cycloadditions of indolyl delocalized metal-allyl species for the enantioselective synthesis of cyclopenta[b]indoles and pyrrolo[1,2-a]indoles

• 作者: Fei Tian Wu-Lin Yang Tao Ni Jian Zhang Wei-Ping Deng
• 来源期刊: 中国科学：化学（英文版）
• 年，卷（期）: 2021,（1）
• 所属期刊栏目: ARTICLES
• 页码范围: 34-40
• 页数: 7页
• 语种: 英文

摘要

The development of novel synthons and efficient methods to synthesize chiral polycyclic indoles has been a hot topic in organic synthesis and medicinal chemistry owing to their broad applications in medicines,pesticides,and other functional molecules.Here,we disclosed novel indolyl substituted metal-allyl zwitterionic intermediates through the decarboxylation of conveniently available vinyl indoloxazolidones,which could be regarded as two types of dipolar species through the anionic delocalization.The palladium-π-allyl species tended to serve as an all-carbon 1,3-dipole in the asymmetric[3+2]cycloaddition with electron-deficient alkenes,which furnished polysubstituted cyclopenta[b]indoles with high regio-and stereoselectivities.Meanwhile,the iridium-π-allyl species was recognized as an aza-1,3-dipole in asymmetric[3+2]cycloaddition with in situ generated Cl ammonium enolates,affording pyrrolo[1,2-a]indoles with high diastereo-and enantioselectivities.In addition,the dipolar cycloadditions could be easily scaled-up and several synthetic transformations of the cycloadducts were demonstrated for the rapid synthesis of diverse chiral polycyclic indoles.