Modular Synthesis of Novel Chiral Phosphorous Triamides Based on (S)-N-(Pyrrolidin-2-ylmethyl)aniline and Their Application in Asymmetric Catalysis

A set of new P-chiral phosphorous triamides (PTAs) based on the (S)-N-(pyrrolidin-2-ylmethyl)aniline backbone was prepared by modular synthetic procedures. The chirality at phosphorus can be controlled to a large extent by the synthetic route, and high diastereomeric purities were achieved for most of the reported ligands. This ligand family was evaluated in the copper-catalysed Michael addition of diethylzinc to cyclohex-2-enone, and moderate enantioselectivities were achieved. In the asymmetric nickel-catalysed hydrovinylation of styrene, good conversions and chemoselectivities, together with promising enantioselectivities of up to 60%, were obtained with the new PTA ligands even at relatively high reaction temperatures. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)