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Oxidative Cleavage of Alkenes by O2 with a Non-Heme Manganese Catalyst

Zhiliang Huang, Renpeng Guan, Muralidharan Shanmugam, Elliot L. Bennett, Craig M. Robertson, Adam Brookfield, Eric J. L. McInnes and Jianliang Xiao*

*Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K., Email: j.xiaoliverpool.ac.uk

Z. Huang, R. Guan, M. Shanmugam, E. L. Bennett, C. M. Robertson, A. Brookfield, E. J. L. MeInnes, J. Xiao, J. Am. Chem. Soc., 2021, 143, 10005-10013.

DOI: 10.1021/jacs.1c05757


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Abstract

A light-driven, Mn-catalyzed protocol for the selective oxidation of alkenes to carbonyls under 1 atm of O2 provides ketones and aldehydes under clean, mild conditions. Aromatic as well as various nonactivated aliphatic alkenes could be oxidized with a first row, biorelevant metal catalyst. Moreover, the protocol shows a very good functional group tolerance.


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proposed mechanism



Standard procedure for aerobic oxidative cleavage of alkenes

To an oven dried Schlenk tube, [Mn(dtbpy)2(OTf)2] (8.9 mg, 2 mol%) was added. Then the reaction tube was vacuumed and purged with oxygen via an oxygen balloon. Methanol (1 mL) and 2,2,2-trifluoroethanol (1 mL) was injected through a syringe. Finally, after the addition of an alkene (0.5 mmol), the reaction tube was allowed to stir at 20C under blue light for 5 - 24 h until the alkene was consumed by TLC analysis. After the crude mixture was concentrated under vacuum, the pure product was obtained by flash chromatography on silica gel with hexane/ethyl acetate.


Key Words

oxidative cleavage of alkenes, oxygen, photochemistry


ID: J48-Y2021