Phosphine Based Gold Catalysts for the Asymmetric Hydroamination of Alkenes: Effects of Silver, Anion and Solvent

Nowadays, achieving highly enantioselective gold catalysed hydroamination of alkenes remain challenging1 and we would like to report herein our last results. Following our works on activated alkenes2a and allenes,2b the... [ view full abstract ]

Nowadays, achieving highly enantioselective gold catalysed hydroamination of alkenes remain challenging¹ and we would like to report herein our last results. Following our works on activated alkenes^2a and allenes,^2b the intramolecular gold(I) catalysed asymmetric hydroamination of alkenes was studied screening a wide range of phosphine ligands (Figure 1). First, high yields and average enantioselectivities were obtained using phosphoramidite ligands and mild reaction conditions.^2c Second, various binuclear gold(I) catalysts based on diphosphine ligands were studied. A specific gold(I) species proved to perform efficiently the intramolecular hydroamination of alkenes at mild temperatures with high yields and enantioselectivities (Figure 1).^2d-f Combined studies by X-ray diffraction analyses, diffusion ¹H NMR, mass spectrometry and DFT calculations showed the reaction mechanism was driven by effects of solvents, silver salts and anions.^2d-f 

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