Dimethylmalonyltrialkylphosphoranes: New General Reagents for Esterification Reactions Allowing Controlled Inversion or Retention of Configuration on Chiral Alcohols
作者:James McNulty、Alfredo Capretta、Vladimir Laritchev、Jeff Dyck、Al J. Robertson
DOI:10.1021/jo026639y
日期:2003.2.1
through reaction of a trialkylphosphine with 2-chlorodimethylmalonate in the presence of triethylamine. These new reagents promote the condensation reaction of carboxylic acids with alcohols to provide esters along with trialkylphosphine oxide and dimethylmalonate. The condensation reaction of chiral secondary alcohols can be controlled to give either high levels of inversion or retention through a
[EN] PHOSPHORANES AS COUPLING AGENTS AND THEIR PREPARATION<br/>[FR] PHOSPHORANES UTILISES EN TANT QU'AGENTS COUPLEURS ET LEUR PREPARATION
申请人:CYTEC CANADA INC
公开号:WO2004000778A1
公开(公告)日:2003-12-31
Provided is a use as a coupling agent for condensation reactions of a compound of formula (I): wherein each of R1, R2, and R3 is independently H, hydrocarbyl, or hydrocarbyloxy, provided that not more than one of R1, R2, and R3 is H ; and at least one of Y1 and Y2 is an electron-withdrawing group and the other, if not an electron-withdrawing group, is H or a group that has no electron-donating properties, with the proviso that when one of Y1 and Y2 is H, the other is not -CN. Some of the compounds of formula (I) are novel, and methods of their preparation are also provided.
Dimethylmalonyltrialkylphosphoranes: probing the steric effect on phosphorus and its stereochemical consequence in esterification reactions of chiral secondary alcohols
High chemical yields and high levels of stereochemical inversion are demonstrated in the phosphorane-mediated esterification reaction of chiral alcohols with non-hindered carboxylic acids through the incorporation of sterically non-hindered alkyl groups of phosphorus.