Lewis acid promoted regio- and stereoselective hetero nucleophilic addition to a piperidinyl aziridine. Synthesis of trans 3-amino-4-substituted piperidines

A piperidinyl aziridine underwent alcoholic nucleophilic addition with alcohols to result in corresponding trans 3-amino-4-substituted piperidines. The addition reaction was catalyzed by BF3·OEt2 in excellent regio- and stereoselectivity. The application of this method was extended to the addition of thiols, acids and halogens with sustained regio- and stereoselectivity.