Enantioselective reduction of ketophosphonates using adducts of chiral natural acids with sodium borohydride
作者:E.V. Gryshkun、V. Nesterov、O. I. Kolodyazhnyi
DOI:10.3998/ark.5550190.0013.409
日期:——
asymmetric reduction of αand β ketophosphonates using chiral complexes prepared from sodiumborohydride and natural aminoacids or tartaric acids was developed. Reduction of α or β ketophosphonates by these reagents led to formation of chiral (S)or (R)hydroxyphosphonates. Reduction of chiral di-(1R,2S,5R)-menthylketophosphonates by the chiral complexes NaBH4/(R,R)-proline or NaBH4/(R,R)-tartaric acid due to
作者:A. O. Kolodyazhnaya、V. P. Kukhar、O. I. Kolodyazhnyi
DOI:10.1134/s1070363208110091
日期:2008.11
Phospha-aldol reaction of dialkylphosphites with carbonyl compounds is catalyzed by cinchonine alkaloids and thier modified derivatives to give optically active hydroxyphosphonates. The use of diastereomeric pairs of alkaloids allowed obtaining both optical antipodes of hydroxyphosphonates. Cinchonine alkaloids show the highest enantioselectivity as organic catalysts. It was found that ordinary crystallization of some enantiomerically enriched hydroxyphosphonates leads to isolation of the enantiomerically pure stereoisomers. Hydroxyphosphonic acids were obtained by hydrolysis of phosphonates. Fluoroalkylphosphonates were obtained by reaction with diethylaminotrifluorosulfurane (DAST).