A Two-Step Synthesis of 3,4-Disubstituted Piperidines from Acyclic Precursors through Tetrahydropyridine Intermediates
作者:José Aurrecoechea、José Gorgojo、Carlos Saornil
DOI:10.1055/s-0029-1218599
日期:2010.2
Cyclocondensation between acyclic 5-aminopent-2-enoate esters and aliphatic aldehydes containing an unsubstituted α-methylene unit affords 1,2,3,4-tetrahydropyridine derivatives in good yields. The reaction has been applied to a range of aldehydes, showing good functional group tolerance. Chemoselective hydride reduction of the enamine double bond provides 3,4-disubstituted tertiary piperidine derivatives with acceptable to good diastereoselectivities, whereas catalytic hydrogenation of N-benzyl derivatives leads directly to the corresponding secondary piperidines.