Electron transfer catalysis mediated by 3d complexes of redox non-innocent ligands possessing an azo function: a perspective

Abstract

It was first reported almost two decades ago that ligands with azo functions are capable of accepting electron(s) upon coordination to produce azo-anion radical complexes, thereby exhibiting redox non-innocence. Over...

Ruthenium complexes of redox non-innocent aryl-azo-oximes for catalytic α-alkylation of ketones and synthesis of 2-substituted quinolines

“…23–29 The chemistry of redox non-innocent ligands containing azo functions has developed over the past two and a half decades 30–43 and at present the catalytic role of their complexes is under intense investigation. 44–62 In the majority of the cases, ligands are of tridentate azo pincer type, where the ligated azo moieties have the ability to behave as electron pockets to store electron/s in the form of an azo anion-radical. In addition, the reserved electron/s may be transferred to suitable centres to bring about catalytic reduction and this concept has been widely employed to synthesize several value-added chemicals of pharmaceutical and industrial importance, in a cost effective and atom efficient manner.…”

A sustainable strategic approach for N-alkylation of amines with activation of alcohols triggered via a hydrogen auto-transfer reaction using a Pd(ii) complex: evidence for metal–ligand cooperativity

“…Aryl-azo scaffolds ([-NvN-] 0/•−/2− ), one type of redox-active ligand, have garnered a lot of attention in the last few years due to their wide range of redox behaviors. 4,6,11,12,39 However, their potential in catalysis has been less explored. There are only a few reports on such complexes being utilised as catalysts for C-N cross-coupling or alcohol dehydrogenation reactions.…”