# Lewis acid/NHC dual catalysis for regioselective vicinal decarboxylative carbonylation–acylation of alkenes

## TL;DR

A new catalytic system enables precise chemical modification of alkenes by adding two carbonyl groups in a controlled way.

## Contribution

A novel Lewis acid–thiazolium NHC catalytic system enables regioselective vicinal decarboxylative carbonylation–acylation of alkenes.

## Key findings

- The reaction proceeds via a concerted single-electron-transfer (SET) process involving a Breslow intermediate and a Lewis acid–activated NHPI ester.
- The method allows efficient CO incorporation even with sterically demanding or conformationally rigid alkyl radicals.
- This strategy provides a new platform for C1 exchange and regioselective recombination of radical intermediates.

## Abstract

Vicinal difunctionalization of alkenes offers a powerful route to complex carbon architectures by installing two distinct groups. Herein, we describe a novel Lewis acid–thiazolium NHC catalytic system that enables precise control of a single-electron-transfer (SET) process to achieve CO-incorporated vicinal decarboxylative carbonylation–acylation of alkenes. The reaction is proposed to proceed via a concerted SET between the enolate form of the Breslow intermediate and a Lewis acid–activated NHPI ester, followed by CO trapping and regioselective recombination of multiple radical intermediates to install two distinct carbonyl groups. This strategy constitutes a new platform for C1 exchange and enables efficient CO incorporation even with sterically demanding or conformationally rigid alkyl radicals.

Herein, we describe a novel Lewis acid–thiazolium NHC catalytic system that enables precise control of a single-electron-transfer (SET) process to achieve CO-incorporated vicinal decarboxylative carbonylation–acylation of alkenes.