New Stereoselective Syntheses of cis- and trans-2-Methyl-4-arylpiperidines.

A stereoselective approach has been developed for the synthesis of cis- and trans-2-methyl-4-arylpiperidines from a common intermediate. The Ni-catalyzed hydrogenolysis of N-Boc-2-methyl-4-aryl-4-piperidinols, obtained by addition of organometallic reagents on N- Boc-2-methyl-4-piperidone, afforded the trans derivatives with Lip to 95% selectivity whereas the corresponding cis isomers were obtained in the presence of palladium catalysts. (C) 2003 Elsevier Science Ltd. All rights reserved.