Chiral Monodentate Trialkylphosphines Based on the Phospholane Architecture
The development of efficient chiral monodentate phosphine ligands lags behind that of the bidentate congeners. This holds especially true for highly electron rich chiral phosphine analogues able to replace the ubiquitous tricyclohexylphosphine and tri-tert-butylphosphine in catalytic asymmetric transformations. We present a convenient and modular synthesis of a set of chiral monodentate ligands with different steric demands based on the popular phospholane scaffold. Their steric and electronic properties were determined by their corresponding nickel and palladium complexes. They represent good mimics of the popular tricyclohexylphosphine and tri-tert-butylphosphine ligands. Their potential was subsequently evaluated in palladium-catalyzed asymmetric C(sp(3))-H functionalization leading to indolines.