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Oxidation of Alkenes with H 2 O 2 by an in-Situ Prepared Mn(II)/Pyridine-2-carboxylic Acid Catalyst and the Role of Ketones in Activating H 2 O 2

2012; American Chemical Society; Volume: 2; Issue: 6 Linguagem: Inglês

10.1021/cs3002226

2155-5435

Jiajia Dong, Pattama Saisaha, Tim G. Meinds, Paul L. Alsters, Edwin G. Ijpeij, Ruben P. van Summeren, Bin Mao, Martín Fañanás‐Mastral, Johannes W. de Boer, Ronald Hage, Ben L. Feringa, Wesley R. Browne,

Porphyrin and Phthalocyanine Chemistry

A simple, high yielding catalytic method for the multigram scale selective epoxidation of electron-rich alkenes using near-stoichiometric H2O2 under ambient conditions is reported. The system consists of a Mn(II) salt (<0.01 mol %), pyridine-2-carboxylic acid (<0.5 mol %), and substoichiometric butanedione. High TON (up to 300 000) and TOF (up to 40 s–1) can be achieved for a wide range of substrates with good to excellent selectivity, remarkable functional group tolerance, and a wide solvent scope. It is shown that the formation of 3-hydroperoxy-3-hydroxybutan-2-one from butanedione, and H2O2 in situ, is central to the activity observed.