Journal of the American Chemical Society, Vol.133, No.45, 18066-18069, 2011
Chiral Allene-Containing Phosphines in Asymmetric Catalysis
We demonstrate that allenes, chiral 1,2-dienes, appended with basic functionality can serve as ligands for transition metals. We describe an allene-containing bisphosphine that, when coordinated to Rh(I), promotes the asymmetric addition of arylboronic acids to alpha-keto esters with high enantioselectivity. Solution and solid-state structural analysis reveals that one olefin of the allene can coordinate to transition metals, generating bi- and tridentate ligands.