Electrooxidative para-selective C\u2013H/N\u2013H cross-coupling with hydrogen evolution to synthesize triarylamine derivatives

Kun Liu,Shan Tang,Shengchun Wang,Minzhu Zou,Ting Wu,Hengjiang Cong,Aiwen Lei

doi:10.1038/s41467-019-08414-8

Abstract

Oxidative C–H/N–H cross-coupling is one of the most atom-economical methods for the construction of C–N bonds. However, traditional oxidative C–H/N–H cross-coupling either required the use of strong oxidants or high reaction temperature, which makes it difficult to tolerate redox active functional groups. Herein we describe an external chemical oxidant-free electrooxidative C–H/N–H cross-coupling between electron-rich arenes and diarylamine derivatives. Under undivided electrolytic conditions, a series of triarylamine derivatives are produced from electron-rich arenes and diarylamine derivatives with high functional group tolerance. Both of the coupling partners are redox active in oxidative C–H/N–H cross-coupling, which enables high regioselectivity in C–N bond formation. Exclusive para-selectivity is observed for the coupling with anilines.

Highlights

Oxidative C–H/N–H cross-coupling is one of the most atom-economical methods for the construction of C–N bonds
Research on oxidative aryl C–N bond formation remains elusive in its early stages when compared with the development of oxidative cross-coupling for C–C bond formation
Diarylamines were tested under the standard conditions

Summary

Introduction

Oxidative C–H/N–H cross-coupling is one of the most atom-economical methods for the construction of C–N bonds. Traditional oxidative C–H/N–H cross-coupling either required the use of strong oxidants or high reaction temperature, which makes it difficult to tolerate redox active functional groups. A series of triarylamine derivatives are produced from electron-rich arenes and diarylamine derivatives with high functional group tolerance Both of the coupling partners are redox active in oxidative C–H/N–H cross-coupling, which enables high regioselectivity in C–N bond formation. Our group have reported an electrooxidative C–H sulfenylation of electron-rich arenes with aromatic thiols[47] Both of the coupling partners were redox active under the utilized electrolytic conditions. We envisioned that oxidative amination between two redox active coupling partners such as aniline derivatives might enable different regioselectivity and broaden the compatibility of functional groups in oxidative C–H amination

Methods

Results

Conclusion