Enantioenriched cyanohydrin O-phosphates: Synthesis and applications as chiral building blocks
Aluminum complexes of the chiral (R)- or (S)-3,3'-bis(diethylaminomethyl)-1,1'-bi-2,2'-naphthol (BINOLAM) ligand behave as efficient catalysts for the enantioselective cyanation-O-functionalization of aldehydes, thereby leading to enantiomerically enriched O-silyl, O-methoxycarbonyl, or O-phosphate derivatives of cyanohydrins. The enantioenriched cyanohydrin-O-phosphates are useful for the synthesis of several enantioenriched compounds such as α-hydroxy esters, β-amino alcohols, and γ-substituted α,β-unsaturated nitriles. Natural products such as (-)-aegeline and (-)-tembamide have been prepared in this manner.