STEREOCHEMISTRY OF AMINE-CATALYZED KNOEVENAGEL REACTIONS
作者:Rikuhei Tanikaga、Naoto Konya、Aritsune Kaji
DOI:10.1246/cl.1985.1583
日期:1985.10.5
The amine-catalyzed Knoevenagel reactions of aldehydes and active methylene compounds containing two activating groups were found to involve many reversible steps, and the diastereomeric intermediary condensation compounds yielded thermodynamically stable products via carbanionic intermediates stabilized and sterically affected by two activating groups.
Simple treatment of aldehydes with the carbonylcompounds (1)[R2COCH2S(O)nAr; n= 0,1,2] and piperidine stereoselectively produces the condensation products (7), the stereochemistry of which is controlled by the steric requirements of two functional groups COR2 and S(O)nAr in a sulphur-stabilized carbanion intermediate.