Chemoselective phosphine-catalyzed cyanoacylation of α-dicarbonyl compounds: a general method for the synthesis of cyanohydrin esters with one quaternary stereocenter

A chemoselective phosphine-catalyzed cyanoacylation of alpha-dicarbonyl compounds is reported. Under the catalysis of P(NMe2)(3), the cyanoacylation of alpha-dicarbonyl compounds such as isatins, alpha-keto esters, and alpha-diketones with acyl cyanides exclusively proceeds under very mild conditions, affording a wide range of cyanohydrin esters bearing one quaternary stereocenter in moderate to excellent yields. It represents the first phosphine-catalyzed cyanoacylation of alpha-dicarbonyl compounds and also provides a general method to prepare fully substituted cyanohydrin esters.