Abstract It is postulated that the catalytic active centre in Sn-Beta and Sn-MCM-41 zeolites for Baeyer-Villiger oxidations involves not only the framework Sn sites but also an associated" basic" oxygen that stabilises the reaction transition state through hydrogen bonding. The presence of these" basic" sites has been studied by cross-polarization MAS NMR H→ Sn, and by carrying out the condensation of ketones with malononitrile. The ...
