The Origin of Catalytic Benzylic C-H Oxidation over a Redox-Active Metal-Organic Framework

Louis Kimberley; Alena M Sheveleva; Jiangnan Li; Joseph H Carter; Xinchen Kang; Gemma L Smith; Xue Han; Sarah J Day; Chiu C Tang; Floriana Tuna; Eric J L McInnes; Sihai Yang; Martin Schröder

doi:10.1002/anie.202102313

The Origin of Catalytic Benzylic C-H Oxidation over a Redox-Active Metal-Organic Framework

Angew Chem Int Ed Engl. 2021 Jul 5;60(28):15243-15247. doi: 10.1002/anie.202102313. Epub 2021 Jun 4.

Authors

Louis Kimberley¹, Alena M Sheveleva¹, Jiangnan Li¹, Joseph H Carter^{1

2}, Xinchen Kang¹, Gemma L Smith¹, Xue Han¹, Sarah J Day², Chiu C Tang², Floriana Tuna^{1

3}, Eric J L McInnes^{1

3}, Sihai Yang¹, Martin Schröder¹

Affiliations

¹ Department of Chemistry, University of Manchester, Manchester, M13 9PL, UK.
² Diamond Light Source, Harwell Science Campus, Oxfordshire, OX11 0DE, UK.
³ Photon Science Institute, University of Manchester, Manchester, M13 9PL, UK.

Abstract

Selective oxidation of benzylic C-H 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-H groups in a broad range of substrates under mild conditions over a robust metal-organic framework material, MFM-170, incorporating redox-active [Cu₂ ^II (O₂ 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 (tert-butyl hydroperoxide) via partial reduction to [Cu^II Cu^I (O₂ CR)₄ ] species.

Keywords: benzylic oxidation; catalysis; copper; electron paramagnetic resonance; metal-organic framework.

Abstract

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