Design and synthesis of new chiral phosphorus–olefin bidentate ligands and their use in the rhodium-catalyzed asymmetric addition of organoboroxines to N-sulfonyl imines
Novel chiral phosphorus-olefin bidentate ligands have been synthesized in a few steps from a readily available enantiopure compound. These ligands have been applied to a rhodium-catalyzed asymmetric addition of organoboroxines to N-sulfonyl aldimines, achieving high yield and enantioselectivity.
all cases; the rhodium complexes coordinated with these ligands have been employed as catalysts for the asymmetric1,4-addition of arylboronicacids to α,β-unsaturated ketones, to give 1,4-adducts with high enantioselectivities for cyclic enones and moderate enantioselectivities for acyclic enones.