When metal-catalyzed C–H functionalization meets visible-light photocatalysis

Lucas Guillemard,Joanna Wencel-Delord

doi:10.3762/bjoc.16.147

Abstract

While aiming at sustainable organic synthesis, over the last decade particular attention has been focused on two modern fields, C–H bond activation, and visible-light-induced photocatalysis. Couplings through C–H bond activation involve the use of non-prefunctionalized substrates that are directly converted into more complex molecules, without the need of a previous functionalization, thus considerably reduce waste generation and a number of synthetic steps. In parallel, transformations involving photoredox catalysis promote radical reactions in the absence of radical initiators. They are conducted under particularly mild conditions while using the visible light as a cheap and economic energy source. In this way, these strategies follow the requirements of environment-friendly chemistry. Regarding intrinsic advantages as well as the complementary mode of action of the two catalytic transformations previously introduced, their merging in a synergistic dual catalytic system is extremely appealing. In that perspective, the scope of this review aims to present innovative reactions combining C–H activation and visible-light induced photocatalysis.

Highlights

In recent years, the field of synthetic chemistry has witnessed a profound evolution
Due to the growing environmental awareness, organic chemists face nowadays an urgent need of developing much more sustainable and environmentally benign routes to afford molecular complexity from simple precursors, while concomitantly limiting the number of steps and waste generation. Following this general key objective, the landscape of organic synthesis has been clearly changed by the development of ecofriendly methodologies such as metal-catalyzed C–H activations, visible-light-induced photocatalysis, electrosynthesis, enzyme catalysis, and others
Each of these techniques aims at accessing complex molecules while limiting ecological footprint

Summary

Introduction

The field of synthetic chemistry has witnessed a profound evolution. Due to the growing environmental awareness, organic chemists face nowadays an urgent need of developing much more sustainable and environmentally benign routes to afford molecular complexity from simple precursors, while concomitantly limiting the number of steps and waste generation. Following this general key objective, the landscape of organic synthesis has been clearly changed by the development of ecofriendly methodologies such as metal-catalyzed C–H activations, visible-light-induced photocatalysis, electrosynthesis, enzyme catalysis, and others.

Objectives

Conclusion