[Rh(O2CCHCHMe)(PPh3)(Ph2PO2CCHCHMe)] in high yield. Hydrogenation of hexa-2,4-dienoic acid gives hex-4-enoic acid and hexanoic acid and evidence is presented that these two products are obtained from hydrogenation of the mixed anhydride (hex-4-enoic acid as product) or of the directly bonded anion (hexanoic acid as product). Attempts to promote high enantioselectivity in the hydrogenation of PhCHCMeCO2H by using [
[RhCl(PPh 3)n(Ph 2 PO 2 CCR CR'R'')](n = 1或2)或[Rh(PPh 3)2(Ph 2 PO 2 CCR CR'R'')形式的络合物PF 6(R,R',R''= H,烷基或芳基)已显示在添加碱(KOH或NEt 3)存在下比[RhCl(PPh 3)更有效地催化
丙烯酸的氢化。)3 ]。机理研究表明,活性物质为[Rh(O 2 CCR CR'R″)(PPh 3)(Ph 2 PO 2 CCRCR'R'')],其中混合酸酐既通过
磷原子又通过双键结合。在混合酸酐的双键氢化后,通过碱催化的酯交换反应在混合酸酐的
磷原子处引入新的底物。这以[RhCl(PPh 3)2(Ph 2 PO 2 CCH 2 CH 2 Me)]的反应为模型,该反应以两种异构形式存在,一种形式的混合酸酐仅通过P结合,而另一种形式的混合酸酐仅通过P结合。通过P和O或[Rh(PPh 3)2(Ph 2 PO