Method for the in situ preparation of chiral compounds derived from oxazaborolidine-borane complexes which are used in asymmetric reduction reactions
申请人:Burgos Alain
公开号:US20070055068A1
公开(公告)日:2007-03-08
A process for the in situ preparation of chiral compounds derived from oxazaborolidine-borane complexes, wherein a metal borohydride, a Lewis base and an inorganic acid ester are brought together and an optically active amino alcohol and optionally a halide are then added. The compound obtained is a complex that is useful as a catalyst in asymmetric reduction reactions. The reaction is performed by adding the substance to be reduced, particularly prochiral ketones or ether oximes, in order to synthesize chiral alcohols or chiral amines.
The present invention relates to a process for producing optically active halomethyl phenyl carbinols of the formula (1), comprising reducing halomethyl phenyl ketones of the formula (2) using an asymmetric reducing agent obtained from boranes and optically active α-phenyl-substituted-β-amino alcohols of the formula (3) or optically active α-non-substituted-β-amino alcohols of the formula (4).
The present invention further relates to a process for producing optically active carbinols, comprising reacting with an unsymmetric ketone, an asymmetric reducing agent obtained from optically active β-amino alcohols of the formula (5), a metal boron hydride and Lewis acid or lower dialkyl sulfuric acid.
Processes for preparing optically active alcohols and optically active amines
申请人:SUMITOMO CHEMICAL COMPANY, LIMITED
公开号:EP0736509A2
公开(公告)日:1996-10-09
A process for preparing an optically active alcohol by reacting a prochiral ketone corresponding to the optically active alcohol and an acid with a mixture of (1) a boron-containing compound selected from the group consisting of i) a borane compound which is obtained from an optically active β-aminoalcohol and a boron hydride; or obtained from the optically active β-aminoalcohol, a metal borohydride and an acid and ii) an optically active oxazaborolidine and (2) a metal borohydride; and a process for preparing an optically active amine by reacting an oxime derivative and an acid with a mixture of (1) a boron-containing compound selected from the group consisting of i) a borane compound which is obtained from an optically active β-aminoalcohol and a boron hydride, or obtained from said optically active β-aminoalcohol, a metal borohydride and an acid and ii) an optically active oxazaborolidine, and (2) a metal borohydride.