Aminophosphonite-phosphite and aminophosphonite-phosphinite ligands with mixed chirality: preparation and catalytic applications in asymmetric hydrogenation and hydroformylation

Aminophosphonite-phosphite and aminophosphonite-phosphinite chiral ligands with mixed stereogenic elements have been prepared in good yields from chiral α-aminoalcohols such as 2-(hydroxymethyl)pyrrolidine and 2-N-ethylammino-1-butanol. These new ligands have been fully characterized; the Rh(I) complexes have been tested in catalytic hydrogenation and hydroformylation reactions. Enantioselectivities up to 70% have been obtained in asymmetric hydrogenation of α-acetamidocinnamic acid, methyl ester; enantioselectivities higher than 30% and regioselectivities higher than 98% have been obtained in asymmetric hydroformylation of vinyl acetate.