Enhanced selectivity by an ‘open-well effect’ in a metalloporphyrin-catalysed oxygenation reaction

Abstract

A selection of aliphatic alkenes, substituted styrenes, and cis-stilbene has been epoxidised with aqueous NaOCl, employing two different porphyrins, Mn(TPP)OAc and Mn(TMP)Cl, as catalysts. Large increases in reaction rate, product selectivity, and stereoselectivity are found with the bulkier TMP ligand. The results are interpreted in terms of an ‘open-well effect’ around the manganese–oxygen active site.