ChemInform Abstract: Asymmetric Alkene Epoxidation with Chromium Oxo Salen Complexes. A Systematic Study of Salen Ligand Substituents.

Abstract

diastereoselective syntheses, enantioselective syntheses diastereoselective syntheses, enantioselective syntheses (incl. cis/trans-isomerism) O 0031 -034Asymmetric Alkene Epoxidation with Chromium Oxo Salen Complexes. A Systematic Study of Salen Ligand Substituents.-In the asymmetric epoxidation of E-β-methylstyrene, the title complexes with halogeno-substituents in the 3,3'-and 6,6'-positions, e.g. (I), afford the highest enantioselectivity. Use of triphenylphosphine oxide as donor ligand and of nitrate counter ion is beneficial in most cases. -(O'MAHONY, COLM P.; MCGARRIGLE, EOGHAN M.; RENEHAN, MARIE F.; RYAN, KENNETH M.; KERRIGAN, NESSAN J.; BOUSQUET, CLAUDINE; GILHEANY, DECLAN G.; Org. Lett. 3 (2001) 22, 3435-3438; Dep. Chem., Univ. Coll., Belfield, Dublin 4, Ire.; EN)