Efficient process to induce enantioselectivity in procarbonyl compounds

摘要

The present invention provides an efficient method to induce the enantioselectivity in procarbonyl compounds using chiral organometallic complexes. The present invention also provides a method for producing chiral organometallic complexes using a chiral additive, achiral additive, a base and a metal salt.

主权项

1. A process for the preparation of an amino alcohol of formulacomprising the steps of
a) treating (1R,2S)—N-pyrrolidinyl norephedrine of formulaand trifluoroethanol (F3CCH2OH) with sodium hydride to obtain a sodium salt of (1R,2S)—N-pyrrolidinyl norephedrine and trifluoroethanol,
b) adding a zinc salt to the resultant sodium salts of (1R,2S)—N-pyrrolidinyl norephedrine and trifluoroethanol to obtain chiral (1R,2S)—N-pyrrolidinyl norephedrine and trifluoroethanol zincate complex of formula, c) reacting a terminal alkyne compound of formula with sodium hydride and MgCl2 to give a cyclopropylacetylide complex of formula d) mixing the chiral (1R,2S)—N-pyrrolidinyl norephedrine and trifluoroethanol zincate complex with the cyclopropylacetylide complex of formulato obtain chiral organozinc complex of formula e) mixing the chiral organozinc complex with a ketone of formula to obtain the amino alcohol.