Toward Greener Oxidative Transformations: Base‐Metal Catalysts and Metal‐Free Reactions

Abstract

In this account, the advances in base-metal-catalyzed oxidative transformations and metal-free oxidation reactions developed in our group are summarized and discussed. Related achievements from other research groups are also discussed.

Metal-Free Dehomologative Oxidation of Arylacetic Acids for the Synthesis of Aryl Carboxylic Acids

“…Inspired by recently developed iodine-mediated oxidative C–H functionalization reactions by using DMSO as a solvent as well as an oxidant, we envisaged that a halide-containing reagent could be used as a promoter for the functionalization of C–H bonds in arylacetic acids. Initially, we studied the influence of different catalysts or promoters, oxidants, and solvents on the oxidative dehomologation reaction of phenylacetic acid ( 1a ).…”

Radical bicyclization of 1,6-enynes with sulfonyl hydrazides by the use of TBAI/TBHP in the aqueous phase

“…1 However, most traditional approaches for these transformations still require transition-metal catalysts to facilitate the desired conversion and restrain the side reactions, inevitably leading to environmentally harmful metal residues in the process of reaction and thus limiting their applications in the chemical industry to some extent. 2 To the best of our knowledge, iodine as a nonmetallic element can serve as an alternative catalyst for transition-metals in some reactions because of its multiple valence states and moderate redox potentials. 3 In the past few years, iodide ion-promoted radical reactions have progressed rapidly, especially the tetrabutylammonium iodide (TBAI)– tert -butyl hydroperoxide (TBHP) combined system, arousing considerable interest from chemists.…”