Attractive aerobic access to the α,β-unsaturated acyl azolium intermediate: oxidative NHC catalysis via multistep electron transfer

L Ta,H Sundén,A Axelsson

doi:10.1039/c5gc01965f

Abstract

Employing a system of electron transfer mediators (ETMs) enables the use of oxygen as the terminal oxidant for oxidative NHC-catalyzed reactions.

Highlights

Attractive aerobic access to the α,β-unsaturated acyl azolium intermediate: oxidative N-heterocyclic carbene (NHC) catalysis via multistep electron transfer†
To replace high molecular weight oxidants with air (O2) we introduce multistep electron transfer NHC catalysis
As a part of our interest in NHC catalysis,[20] a strategy for oxidative NHC-catalyzed reactions relying on an electron transport chain involving two electron transport mediators (ETMs) that enables efficient aerobic access to the synthetically useful α,β-unsaturated acyl azolium intermediate (Scheme 2c)

Summary

Introduction

Attractive aerobic access to the α,β-unsaturated acyl azolium intermediate: oxidative NHC catalysis via multistep electron transfer†. To replace high molecular weight oxidants with air (O2) we introduce multistep electron transfer NHC catalysis. The method provides a general and selective oxidation of the α,β-unsaturated aldehyde derived homoenolate to the synthetically useful α,β-unsaturated acyl azolium intermediate.

Results

Conclusion