Phosphoramidite quinaphos‐Type Ligands for Highly Selective Ni‐Catalysed Asymmetric C–C Bond Forming Reactions

Monodentate quinaphos phosphoramidites bearing different substituents in the 2‐position of the 1,2‐dihydroquinoline backbone were synthesised and characterised. Computational, NMR spectroscopic and X‐ray crystallographic methods were used for the elucidation of the structure in solution and in the solid state. Diastereomerically pure ligands were used in the nickel‐catalysed asymmetric hydrovinylation of styrene as well as in the cycloisomerisation of diethyl diallylmalonate. Enantiomeric excesses up to 91 % for the hydrovinylation reaction and up to 46 % for the cycloisomerisation reaction were obtained, accompanied with unprecedented high activities and regioselectivities. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)