A palladium‐catalyzed dehydrogenative coupling between diarylamines and olefins has been discovered for the synthesis of substituted indoles. This intermolecular annulation approach incorporates readily available olefins for the first time and obviates the need of any additional directing group. An ortho palladation, olefin coordination, and β‐migratory insertion sequence has been proposed for the
Transition-Metal-Free Synthesis of 1,2-Disubstituted Indoles
作者:Gleb A. Chesnokov、Alexandra A. Ageshina、Maxim A. Topchiy、Mikhail S. Nechaev、Andrey F. Asachenko
DOI:10.1002/ejoc.201900772
日期:2019.8.15
A new robust transition‐metal‐free method for synthesis of 1,2‐disubstituted indoles from easily available tertiary amides is presented. This approach can be performed in a one‐pot two‐step manner directly from secondary amines. Mechanistic studies showed that acyl transfer might be an important step in the course of the reaction. Viability of the presented approach for benzofurans and benzothiophenes