Biologically inspired nonheme iron complex-catalyzed cis-dihydroxylation of alkenes modeling Rieske dioxygenases

The development of selective catalytic oxidation systems for alkene cis-dihydroxylation under environ-mentally benign conditions is an important goal that has long been pursued in the fields of synthetic and biomimetic chemistry and catalysis. Excellent examples for cis-dihydroxylation of alkenes are natu-rally occurring nonheme iron-dependent Rieske dioxygenases capable of performing aerobic regio-and stereoselective cis-dihydroxylation that is involved in the degradation of aromatics, with both oxygen atoms of O2 incorporated into the cis-dihydrodiol product. Inspired by the structural features of the non-heme iron enzyme center and the reaction mechanisms that underlie their efficacy to catalyze cis- dihydroxylation utilizing O2 and NADH as co-substrates, numerous nonheme iron complexes have been designed as the functional models of Rieske dioxygenases and demonstrated that those nonheme iron models catalyze the cis-dihydroxylation of alkenes with H2O2 as a terminal oxidant, yielding the cis- dihydrodiol products selectively. In this review, we describe recent developments of biologically inspired nonheme iron complexes for cis-dihydroxylation catalysis together with the evolution of the postulated reaction mechanisms to rationalize the experimental observations and the dichotomy between alkene cis-dihydroxylation and epoxidation, with particular emphasis on the structure-reactivity correlation of catalysts. These studies would provide important insights into the fundamental reaction pathways in enzymatic reactions and contribute to the rational design of efficient and selective bioinspired cis- dihydroxylation catalysts. (c) 2022 Published by Elsevier B.V.