Enantioselective conjugate reduction of a wide range of α,β-unsaturated carboxylic esters was achieved using chiral Ir N,P complexes as hydrogenation catalysts. Depending on the substitution pattern of the substrate, different ligands perform best. α,β-Unsaturated carboxylic esters substituted at the α position are less problematic substrates than originally anticipated and in some cases α-substituted substrates actually reacted with higher enantioselectivity than their β-substituted analogues. The resulting saturated esters with a stereogenic center in the α or β position were obtained in high enantiomeric purity.
Enantioselective conjugate reduction of a wide range of α,β-unsaturated carboxylic n class="Chemical">esters was achieved usinpan>g chiral Ir N,P complexes as hydrogenpan>ation catalysts. Depenpan>dinpan>g on the substitution pattern of the substrate, differenpan>t ligands perform best. α,β-Unsaturated carboxylic n class="Chemical">esters substituted at the α position are less problematic substrates than originally anticipated and in some cases α-substituted substrates actually reacted with higher enantioselectivity than their β-substituted analogues. The resulting saturated esters with a stereogenic center in the α or β position were obtained in high enantiomeric purity.