abstract |
A novel phosphine compound having excellent properties (chemical selectivity, enantioselectivity, catalytic activity) as a catalyst for asymmetric syntheses, especially asymmetric hydrogenation. A phosphine-phosphorane compound represented by the following general formula: <CHEM> (wherein R<1> represents hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, R<2>, R<3>, R<4>, and R<5> are the same or different, and each represents hydrogen atom, or an alkyl group having 1 to 6 carbon atoms, etc., and each of R<2> and R<3>, R<3> and R<4>, and R<4> and R<5> may be together combined to form a ring which may contain one or more (preferably 1 to 2) oxygen atoms, and R<6> and R<7> are the same or different, and each represents a linear or branched alkyl group having 1 to 6 carbon atoms, etc.). |