A new method for stereoselective homoallylic amine synthesis

Abstract

Nitrile oxide cycloadditions to readily available allylic diphenylphosphine oxides 2 proceeded regioselectively and stereoselectively to give 5-(1′-diphenylphosphinoylalkyl)isoxazolines 4 and 5. These heterocycles were reduced to δ-amino-β-hydroxyalkyldiphenylphosphine oxides 6 and 7 using a combination of sodium borohydride and nickel(II) chloride. Stereospecific elimination of diphenylphosphinic acid from the reduction products using sodium hydride in N,N-dimethylformamide gave homoallylic primary amines 8 and 9 of defined stereochemistry.