Asymmetric transfer hydrogenation of 1-phenyl dihydroisoquinolines using Ru(II) diamine catalysts

•A new Ru catalyst for the asymmetric transfer hydrogenation of imines was isolated.•The catalyst applies an N-alkylsulfonyl ligand instead of the common N-arylsulfonyl.•The catalyst is able to reduce both 1-phenyl and 1-alkyl dihydroisoquinolines.•A crystal of the new catalyst was grown and characterized.

A new [Ru(II)(η6-p-cymene)(1R,2R)-N-((1S,2S)-borneol-10-sulfonyl)-1,2-diphenylethylenediamine] catalyst for the asymmetric transfer hydrogenation of both 1-alkyl and 1-aryl dihydroisoquinolines has been isolated. For the first time in this type of reaction, the catalyst employs an N-alkylsulfonyl group instead of N-arylsulfonyl.

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