| Popis: |
α-Phosphinosulphoxides are readily accessible by the reaction of α-lithioalkylsulphoxides with Ph2PCl, and are stable towards internal oxygen transfer when pure. The compound Ph2PCH2S(O)Ph thus prepared was shown to form a cationic rhodium bicyclo[2,2,1]hepta-2,5-diene complex in which the phosphine and sulphoxide form a chelating entity; the structure was confirmed by an X-ray diffraction study. Crystals of the phosphinosulphoxide complex (thf adduct) C27H25F3O4S2PRh; C4H8O are monoclinic, P21/c, a = 10.462, b = 16.500, c = 18.690 A, β = 104.50°, Z = 4, Dc = 1.47 g cm−3, R = 0.041, Rω 0.046 for 4809 unique observed reflections (I > 3 σ(I)). An optically active analogue was prepared from (R)-p-tolyl methyl sulphoxide, and the rhodium complexes were evaluated for catalytic effectiveness in homogeneous hydrogenation. It was demonstrated that 2 1 ligand/rhodium complexes are present under turnover conditions. |
