The Origin of Catalytic Benzylic C−H Oxidation over a Redox‐Active Metal–Organic Framework

Abstract

Selective oxidation of benzylic CÀH compounds to ketones is important for the production of a wide range of fine chemicals, and is often achieved using toxic or precious metal catalysts. Herein, we report the efficient oxidation of benzylic C À H groups in a broad range of substrates under mild conditions over a robust metal-organic framework material, MFM-170, incorporating redox-active [Cu 2 II (O 2 CR) 4 ] paddlewheel nodes. A comprehensive investigation employing electron paramagnetic resonance (EPR) spectroscopy and synchrotron X-ray diffraction has identified the critical role of the paddlewheel moiety in activating the oxidant t BuOOH (tertbutyl hydroperoxide) via partial reduction to [Cu II Cu I -(O 2 CR) 4 ] species.