NEW (OLD) HYDROXO COMPLEXES OF PLATINUM(II) AS CATALYSTS FOR THE BAEYER-VILLIGER OXIDATION OF KETONES WITH HYDROGEN-PEROXIDE

Enantioselective Baeyer-Villiger oxidation of cyclic ketones with hydr ogen peroxide can be obtained using (P-P)Pt(2-van) complexes (P-P*, c hiral diphosphine; 2-van, bis-anion of 2-vanillin) as catalyst precurs ors. An analysis of the activation procedure aimed to the identificati on of the reactive species leads to the isolation of complexes of the type [(P-P)Pt(mu-OH)](2)(2+) (P-P, various diphosphines). The synthesi s of some new species is reported together with their characterization with IR and NMR spectroscopy and conductivity data. It is found that these complexes are catalytically active in the (enantioselective) Bae yer-Villiger oxidation of cyclic ketones with hydrogen peroxide. The b asic nature of the OH ligands is exploited in the reaction with a vari ety of acids including hydrogen peroxide.