The use of new chiral phosphite and amidophosphite ligands in the Rh-catalyzed hydrogenation of dehydro-β-amino acid derivatives

Abstract

New chiral phosphite-type ligands were synthesized. The tests of these ligands in the asymmetric Rh-catalyzed hydrogenation of N-acetyl derivatives of dehydro-β-amino acid esters showed their high enantioselectivity (up to 75% ee). The reaction of nucleophilic addition of phthalimide to disubstituted alkynes offering access to esters of N-phthaloyldehydro-β-amino acids was discovered. Higher conversion and enantioselectivity in the hydrogenation of N-acetyl and N-phtaloyl derivatives of dehydro-β-amino acids were observed in fluorinated alcohols as compared to common organic solvents.