Asymmetric synthesis of α-substituted alkylphosphonates based on symmetrical dialkyl phosphites
作者:O. I. Kolodiazhnyi、E. V. Grishkun、S. Sheiko、O. Demchuk、H. Thoennessen、P. Jones、R. Schmutzler
DOI:10.1007/bf02496414
日期:1999.8
Chiral C2-symmetrical dialkylphosphites and C3-symmetrical trialkyl phosphites, derived from (−)-borneol, (−)-menthol, and 1,2∶5,6-di-O-isopropylidene-α-d-glucofuranose, were studied as the starting reagents for the preparation of chiral organophosphorus compounds. The reactions of C2-symmetrical dialkylphosphites and C3-symmetrical trialkyl phosphites with aldehydes and amines or aldehydes are accompanied
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
Chiral symmetric phosphoric acid esters as sources of optically active organophosphorus compounds
作者:Oleg I Kolodiazhnyi、Evgen V Grishkun、Serge Sheiko、Oleg Demchuk、Holger Thoennessen、Peter G Jones、Reinhard Schmutzler
DOI:10.1016/s0957-4166(98)00166-9
日期:1998.5
Chiral symmetric di- and trialkylphosphites, derivatives of (-)-borneol, (-)-menthol and (-)-1,2:5,6-di-O-isopropylidene-alpha-D-glucofuranose, were studied as starting reagents for the preparation of chiral organophosphorus compounds. The reaction occurs by asymmetric induction at the alpha-carbon atom of substituted alpha-alkylphosphonates. The stereoselectivity of the reaction depends on the structure of the starting compounds and the reaction conditions. The configuration of the alkylphosphonates was established by NMR spectroscopy, by transformation into alpha-hydroxyalkylphosphonic acids and by X-ray crystal structure analysis. (C) 1998 Elsevier Science Ltd. All rights reserved.
Organic catalysis of phospha-aldol condensation
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).