Divergence in CH alkylation of indoles under Mn catalysis

Abstract

Achieving divergence in CH alkylation of substrates using feedstock chemicals is an attractive paradigm to enable the production of diverse products from the same starting materials. Herein, we report manganese-catalyzed CH alkylation of indole/indolines with alcohols, where product selectivity is achieved through catalyst control. By use of a molecularly defined PNP–Mn(I) complex, tandem double dehydrogenative CH alkylation of indoles is observed. In contrast, an NNN–Mn(II)-based catalyst system provides a diverse range of value-added bis(indolyl)methanes (BIMs) via an interrupted borrowing hydrogen strategy. The present strategy was successfully applied for sustainable, scalable synthesis of several life science molecules (vibrindole A, turbomycin B alkaloid, and antileukemic and anticancer agents) and natural products (gramine, dipterine, etc.).