Studies On Chiral Ni-Catalyzed Asymmetric Decarboxylative Aldol Reaction Of ?(?)ketoacids With ?,?-Unsaturated ?-Ketoesters

Chiral tertiary alcohol compounds are important synthetic motifs in many natural products and pharmaceutical intermediates. Therefore, how to efficiently construct these compounds is one of the key fields for chemists.Thereinto, the asymmetric Aldol reaction of aldehydes or ketones with ?-keto esters in the presence of chiral catalysts represents a versatile strategy to construct chiral tertiary alcohol framework.?-ketoacids are regarded as attractive surrogates of ketones. The asymmetric decarboxylative Aldol reaction of ?-ketoacids with ?,?-unsaturated ?- ketoesters provides a facile access to chiral tertiary alcohol compounds bearing a chiral quaternary carbon center which contains several functional groups(carbon-carbon double bond, ester, and carbonyl) that can be transformed to useful compounds easily.In this thesis, an enantioselective Aldol reaction of ?-ketoacids with ?,?- unsaturated ?-ketoesters in the presence of a chiral Ni(II) complex has been developed. A series of chiral tertiary alcohol compounds were obtained with good to excellent yields(70-99%) and enantioselectives(65-99%). In addition, the products can be further transformed to optically pure isoxazoline derivatives and ?-hydroxy-?-butyrolactone derivatives. What's more, 13 C NMR experiments have also been proceeded to elucidate the mechanism of this Aldol reaction.