Light-induced homolysis of copper(ii)-complexes – a perspective for photocatalysis

Abstract

Over the past decade, photocatalysis has developed as a powerful strategy for the selective functionalization of molecules through radical intermediates. Besides the well-established iridium- or ruthenium-based photocatalysts, which ideally fulfill...

Cu(ii) salts as terminal oxidants in visible-light photochemical oxidation reactions

“…The direct irradiation of copper complexes to generate radical intermediates has emerged as an alternate strategy for initiating oxidative photochemical transformations. 24 When an appropriately substituted copper complex is irradiated, it can undergo a ligand-to-metal charge transfer (LMCT) transition in which an electron is formally promoted from a filled orbital centered on the nucleophilic ligand to an empty orbital on copper. This event results in a single-electron reduction of the copper center and generates a radical on the ligand, which can be involved in a variety of transformations (Scheme 13).…”

A new era of LMCT: leveraging ligand-to-metal charge transfer excited states for photochemical reactions

“…Many of these complexes are comprised of rst row transition metals with strong p and s donors and notable examples include cobalamin, cobaloxime, tris(bipyridine)cobalt(III), bis(2,6-diguanidylpyridine)cobalt(III) complexes, copper(II) phenanthroline-based complexes, and a variety of metal halide complexes. 62,[85][86][87][88][89] Several of these complexes, particularly metal halide complexes, have also gained traction as photoredox catalysts to drive a variety of organic transformations. 1,86,[89][90][91][92][93] Like d 5 complexes, these electronic congurations enable a variety of d-d transitions and MLCT excited states, as illustrated in Fig.…”

Recent advances in catalytic decarboxylative transformations of carboxylic acid groups attached to a non-aromatic sp2or sp carbon

“…copper( ii )-complexes, despite having exceptionally short excited-state lifetimes. 121 The viability of this concept is yet to be investigated in more detail for accomplishing decarboxylative transformations. Equally, much room is left for the associated electro- and/or combined electro- and photocatalytic approaches in the future.…”