Chiral Lewis Acid Catalysed Asymmetric Nucleophilic Ring Opening of Cyclohexene Oxide

Article abstract of DOI:10.1016/0957-4166(95)00263-O

Titanium and zirconium complexes of bispicolinic amides catalyze the ring opening of cyclohexene oxide with trimethylsilyl azide as nucleophile.The product, 1-azido-2-trimethylsilyloxycyclohexane, was obtained in up to 71percent enantioselectivity when a catalyst prepared from (S,S)-N,N'-bis(2-pyridinecarboxamide)-1,2-diphenylethane and zirconium tetra-t-butoxide was employed under optimum conditions, which included the addition of a small amount of diethylamine in the catalyst preparation step.The nature of the catalyst is still unknown, but it seems probable that oligomeric metal species are involved.