Diastereoselective Access to Enantiomerically Pure cis-2,3-Disubstituted Pyrrolidines

A straightforward access to enantiomerically pure 2,3-disubstituted pyrrolidines is reported that involves diastereoselective allylation of (R)-phenylglycinol-derived imines and a sequential hydrozirconation-cyclization. A number of pyrrolidine derivatives bearing aryl, heteroaryl, alkyl and alkenyl groups have been prepared in this way. Such compounds are useful building blocks in the synthesis of molecules of biological interest, as illustrated by the syntheses of proline derivatives and the naturally occurring alkaloid (-)-isoretronecanol.