Enantioselective epoxidation of nonfunctionalized alkenes catalyzed by recyclable new homochiral dimeric Mn(III) salen complexes

摘要: Abstract Two recyclable dimeric Mn III salen complexes with geminal methyl groups on the linking carbon atom at 5,5′ position of units were synthesized. They gave a high epoxide yield (>99%) and enantiomeric excess up to >99% in 2 11 h 2 mol% catalyst loading enantioselective epoxidation nonfunctionalized alkenes using NaOCl as oxidant presence Py NO axial base. The reaction was successful even 0.4 mol%, but took longer. recovered easily recycled five times simple separation process. To understand mechanism catalytic reaction, kinetic investigation carried out different concentrations catalyst, oxidant, substrate styrene representative substrate. first order respect did not depend initial concentration An appropriate is proposed.