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
New method for the asymmetric hydroboration of ketophosphonates and the synthesis of phospho-carnitine
作者:Vitaly V. Nesterov、Oleg I. Kolodiazhnyi
DOI:10.1016/j.tetasy.2006.03.025
日期:2006.4
The reduction of alpha- or beta-ketophosphonates with a chiral reactant 1, prepared from sodium borohydride and (R)- or (S)-tartaric acids, led to the formation of both (S)- and (R)-alpha- or beta-hydroxyphosphonates in high yields. The stereoselectivity of the reaction depended on the absolute configurations of 1 and the ketophosphonates. The reduction of di(1R,2S,5R)-menthyl ketophosphonates with (R)-1 proceeded with matched double asymmetric induction to give high diastereomeric excesses of hydroxyphosphonates (up to 96% de). This methodology was used for the preparation of enantiomerically pure phosphonate modified carnitine on a multigram scale. (c) 2006 Elsevier Ltd. All rights reserved.
New Method for the Asymmetric Reduction of Ketophosphonates
作者:Vitaly V. Nesterov、Oleg I. Kolodiazhnyi
DOI:10.1080/10426500701807251
日期:2008.1.14
Chiral reducing reactants were prepared from lithium, sodium, or tetrabutylammonium borohydrides and (S)- or (R)-tartaric acids.