Nickel-catalyzed electrochemical carboxylation of unactivated aryl and alkyl halides with CO2

Guo-Quan Sun,Jin-Gui Wu,Zi-Hao Nie,Wei Zhang,Da-Gang Yu,Zhen Zhang,Li-Li Liao,Li Li

doi:10.1038/s41467-021-27437-8

Abstract

Electrochemical catalytic reductive cross couplings are powerful and sustainable methods to construct C−C bonds by using electron as the clean reductant. However, activated substrates are used in most cases. Herein, we report a general and practical electro-reductive Ni-catalytic system, realizing the electrocatalytic carboxylation of unactivated aryl chlorides and alkyl bromides with CO2. A variety of unactivated aryl bromides, iodides and sulfonates can also undergo such a reaction smoothly. Notably, we also realize the catalytic electrochemical carboxylation of aryl (pseudo)halides with CO2 avoiding the use of sacrificial electrodes. Moreover, this sustainable and economic strategy with electron as the clean reductant features mild conditions, inexpensive catalyst, safe and cheap electrodes, good functional group tolerance and broad substrate scope. Mechanistic investigations indicate that the reaction might proceed via oxidative addition of aryl halides to Ni(0) complex, the reduction of aryl-Ni(II) adduct to the Ni(I) species and following carboxylation with CO2.

Highlights

Electrochemical catalytic reductive cross couplings are powerful and sustainable methods to construct C−C bonds by using electron as the clean reductant
We show a general and practical electrochemical Nicatalytic system, realizing the electrocatalytic carboxylation of challenging aryl chlorides and unactivated alkyl bromides with CO2 (Fig. 1b)
The catalytic electrochemical carboxylation of arylhalides with CO2 avoiding the use of sacrificial electrodes is developed

Summary

Introduction

Electrochemical catalytic reductive cross couplings are powerful and sustainable methods to construct C−C bonds by using electron as the clean reductant. We realize the catalytic electrochemical carboxylation of aryl (pseudo)halides with CO2 avoiding the use of sacrificial electrodes This sustainable and economic strategy with electron as the clean reductant features mild conditions, inexpensive catalyst, safe and cheap electrodes, good functional group tolerance and broad substrate scope. Selective electrocatalytic carboxylation of unactivated aryl chlorides and unactivated alkyl halides with CO2 have rarely been realized[46,47,48,49,50], which are more challenging due to the low reactivity of both unactivated organohalides and CO2 as well as many competing side reactions, such as protonation, β-H elimination, migration, and homodimerization of the generated organometallic reagents and electrochemical decarboxylation of the products[51]. The catalytic electrochemical carboxylation of aryl (pseudo)halides with CO2 avoiding the use of sacrificial electrodes is developed

Methods

Results

Conclusion