Rh(III)-Catalyzed, Highly Selectively Direct C–H Alkylation of Indoles with Diazo Compounds

Kang Wan,Zhan Li,Feng Wang,Xing Qu,Liang Wang

doi:10.3390/catal6060089

Abstract

Rh(III)-catalyzed regioselective alkylation of indoles with diazo compounds as a highly efficient and atom-economic protocol for the synthesis of alkyl substituted indoles has been developed. The reaction could proceed under mild conditions and afford a series of desired products in good to excellent yields.

Highlights

A major goal for the advancement of modern organic chemistry is the development of highly efficient and atom economical synthetic strategies that allow the rapid construction of structurally complex and functionally diverse molecular architectures [1,2]
The methods that allow for direct C2–H alkylation of indoles are still rare
As part of an ongoing research program on the C–H functionalization of indoles [32,33,34,35], we describe catalyst [30]

Summary

Introduction

A major goal for the advancement of modern organic chemistry is the development of highly efficient and atom economical synthetic strategies that allow the rapid construction of structurally complex and functionally diverse molecular architectures [1,2]. In 2014, Yi and coworkers disclosed a Rh(III)‐catalyzed C2‐selective carbenoid a facile and mild Rh(III)-catalyzed highly selectively direct C–H alkylation of indoles with diazo functionalization with diazotized Meldrum’s acid, while the catalyst loading of 5 mol % was compounds. GroupThe on in the C–H alkylation reaction to afford the corresponding products in high to excellent the aryl ring wasgood compatible withgroup this catalytic process, the desired alkylated products reaction showed functional compatibility. The ester group on the arylwere ring obtained in an excellent yield Perhaps more importantly, this protocol was compatible with this catalytic process, and the desired alkylated products were obtained in an could alsoyield be 2, Entries 14 products and 15). with 87% and 88% yields, respectively (Table 2, Entries 14 and 15)

Indole

General Information

Representative Procedure for the C–H Alkylation Reaction

Conclusions