Diastereoselective addition to N-acyliminium ions with aryl- and alkenyl boronic acidsvia a Petasis-type reaction

Abstract

A highly diastereoselective synthesis of 2,3-disubstituted piperidines has been accomplished through nucleophilic additions to N-acyliminium ions with aryl- and alkenyl boronic acids. A reversal of stereoselectivity depending on a β-substituent on the piperidine ring was observed in the alkenylation reactions with (E)-styrylboronic acid. Our strategy was applied in the key step for the synthesis of the neurokinin NK1 receptor antagonist (±)-L-733,060.