Metal-Free Synthesis of Indolopyrans and 2,3-Dihydrofurans Based on Tandem Oxidative Cycloaddition
作者:Subin Choi、Hyeonji Oh、Jeongwoo Sim、Eunsoo Yu、Seunghoon Shin、Cheol-Min Park
DOI:10.1021/acs.orglett.0c01896
日期:2020.7.17
transfer between coupling partners followed by cage collapse allows highly selective cross-coupling while employing only equimolar amounts of coupling partners. Moreover, the mechanistic manifold was expanded for the functionalization of enamines to give the stereoselective synthesis of 2,3-dihydrofurans. This iodine-mediatedoxidative coupling features mild conditions and fast reaction kinetics.
A novel and efficient palladium-catalyzed intramolecular oxidative cyclization of tertiary enamines for the synthesis of 1,3,4-trisubstituted pyrroles and 1,3-disubstituted indoles has been developed. Trifluoroacetic acid plays an important role in the reaction. A series of pyrroles and indoles with substitution patterns that are not easily accessible by traditional routes were synthesized in good
catalytic system has been established for the synthesis of highly functional indolizines throughoxidative [3 + 2] cycloaddition of enamines and pyridotriazoles. This modular platform is compatible with a broad range of functional groups, including natural and complex skeletons, allowing for late-stage modifications. It features a step-economical, highly regioselective, and easy-handling procedure and has been