Several enantiopure diphosphanes 21 were synthesized in three steps from a common precursor 19. The cationic rhodium complexes 22 were screened as catalysts for asymmetric hydrogenation of various alkenes. Enantioselectivities up to 95−98% have been observed in some cases. Enantioselectivities are modest in allylic substitution catalyzed by the corresponding palladium complexes.
几个对映体纯
二膦 21 是由一个共同的前体 19 在三个步骤中合成的。阳离子
铑配合物 22 被筛选为各种烯烃不对称氢化的催化剂。在某些情况下,已经观察到高达 95-98% 的对映选择性。在由相应
钯配合物催化的烯丙基取代中,对映选择性适中。