Electrochemical Cross‐Electrophile‐Coupling for Transition‐Metal‐Free Allylic Carboxylation with Ambient CO₂

Abstract

The use of CO2 as a C1 building block to access carboxylic acids is one of the key aspects in the context of carbon capture and utilization (CCU). Herein we report on an electrochemical carboxylation of allyl esters with CO2 at atmospheric pressure. This strategy enabled to the synthesis of diverse carboxylic acids without the need for a transition metal catalyst. Furthermore, the mechanism was studied through ICP‐MS analysis and cyclic voltammetry studies for the cross‐electrophile CO2 coupling.

Catalyst- and Additive-Free Electrochemical CO2 Fixation into Morita–Baylis–Hillman Acetates

“…From the data collected in Scheme 2 and following literature precedents on the electrochemical reductive carboxylation of electron-deficient olefins, 7i j the reaction mechanism depicted in Scheme 3a is tentatively proposed. Cathodic reduction of 1 ( 1a : –2.08 V vs SCE, see the Supporting Information) renders intermediate radical anion B that, upon successive reduction and loss of the acetate anion, gives key intermediate A (path A).…”

Electrochemical Late-Stage Functionalization

“…Recently, a metal-free electroreductive carboxylation of aryl halides was devised by Qiu (Scheme 69). 143,359…”

“…Recently, a metal-free electroreductive carboxylation of aryl halides was devised by Qiu (Scheme ). , This electroreducitve protocol functioned by utilizing naphthalene as a catalytic mediator without any sacrificial anode material. The naphthalene mediator under the catalytic conditions formed a strong reductant naphthalene anion radical, which reduced the aryl halide generating aryl radical.…”

Selective Electrochemical Halogenation of Functionalized Quinolone

“…Electrochemical synthesis has received increasing attention from synthetic chemists in the past two decades. – In 2017, Baran surveyed the advances in synthetic organic electrochemistry since 2000 and the challenges ahead. Recently, a series of transition-metal-catalyzed and metal-free electrochemical organic synthesis reactions have been reported successfully by Lei’s, – Mei’s, – Ackermann’s, , and other groups.…”