Double and triple asymmetric induction in phosphaaldol reactions
摘要:
A multiple asymmetric induction synthesis was applied to increase the stereoselectivity of the phosphaaldol reaction. The double stereoselectivity was achieved in the reaction of chiral di(1R,2S,5R)-menthyl phosphite 3 with chiral 2,3-D-isopropyliden-(R)-aldehyde 2. The reaction of aldehyde 2 with phosphite 1 in the presence of chiral (R)-ALB catalyst proceeding under stereochemical control of three chiral auxiliaries was the most stereoselective to support the conception of multiplicativity of facial selectivities of chiral reactants involved into the reaction. The stereochemistry of the phosphaaldol reaction was in agreement with Cram's rule. The absolute configuration of the new chiral compounds was established on the basis of NMR and X-ray analysis. (C) 2004 Elsevier Ltd. All rights reserved.
Double and triple asymmetric induction in phosphaaldol reactions
摘要:
A multiple asymmetric induction synthesis was applied to increase the stereoselectivity of the phosphaaldol reaction. The double stereoselectivity was achieved in the reaction of chiral di(1R,2S,5R)-menthyl phosphite 3 with chiral 2,3-D-isopropyliden-(R)-aldehyde 2. The reaction of aldehyde 2 with phosphite 1 in the presence of chiral (R)-ALB catalyst proceeding under stereochemical control of three chiral auxiliaries was the most stereoselective to support the conception of multiplicativity of facial selectivities of chiral reactants involved into the reaction. The stereochemistry of the phosphaaldol reaction was in agreement with Cram's rule. The absolute configuration of the new chiral compounds was established on the basis of NMR and X-ray analysis. (C) 2004 Elsevier Ltd. All rights reserved.
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).
Asymmetric synthesis of phosphathreoninic acid
作者:A. O. Kolodyazhnaya、V. P. Kukhar’、O. I. Kolodyazhnyi
DOI:10.1007/s11176-005-0123-3
日期:2004.12
Double and triple asymmetric induction in phosphaaldol reactions
作者:Anastasia O. Kolodiazhna、Valery P. Kukhar、Alexander N. Chernega、Oleg I. Kolodiazhnyi
DOI:10.1016/j.tetasy.2004.05.022
日期:2004.7
A multiple asymmetric induction synthesis was applied to increase the stereoselectivity of the phosphaaldol reaction. The double stereoselectivity was achieved in the reaction of chiral di(1R,2S,5R)-menthyl phosphite 3 with chiral 2,3-D-isopropyliden-(R)-aldehyde 2. The reaction of aldehyde 2 with phosphite 1 in the presence of chiral (R)-ALB catalyst proceeding under stereochemical control of three chiral auxiliaries was the most stereoselective to support the conception of multiplicativity of facial selectivities of chiral reactants involved into the reaction. The stereochemistry of the phosphaaldol reaction was in agreement with Cram's rule. The absolute configuration of the new chiral compounds was established on the basis of NMR and X-ray analysis. (C) 2004 Elsevier Ltd. All rights reserved.