Reactions of Unsaturated Organometallic Reagents on Trifluoroacetaldimines

Abstract

Allyl zinc reagents, vinyl magnesium bromide and lithium acetylides could easily react without any activation on trifluoroacetaldimines to afford homoallyl, allyl and propargyl amines in good yields. From chiral imines, these amines were obtained in excellent diastereoselectivity (>98%). After N-allylation, homoallyl amines could give access to piperidine derivatives by ring closing metathesis. The allyl amine allowed the synthesis of the trifluoromethyl epoxide 24, fluorinated analog of a key precursor of aspartyl proteases inhibitors.