| Popis: |
The use of catalytic systems based on Cu(I) and Co(II) complexes for addition of tetrachloromethane to alkenes was reported previously [1, 2]; CCl4, as a rule, was taken in a 5 10-fold molar excess. In this work we discovered that platinum(II) phosphine complexes also exhibit a catalytic activity in this reaction, and with these complexes the reaction can be performed with only a slight excess of CCl4 : CCl4 : 1-hexene = 1.3 : 1.0. For example, when a 1 : 1 : 1 (by volume, at 25 C) mixture of CCl4, 1-hexene, and acetonitrile is heated to 67 140 C in the presence of Pt(II) complexes (10 3 10 2 M), an addition product, 1,1,1,3-tetrachloroheptane, is formed in a yield of up to 35% (all the experiments were performed in sealed degassed evacuated ampules). As catalysts we used dichlorobis(triphenylphosphine)platinum(II), dichlorobis[tri(m-tolyl)phosphine] platinum(II), dimethylbis(triphenylphosphine)platinum(II), diiodobis(triphenylphosphine)platinum(II), and other compounds. The reaction can also be performed with other alkenes (1-heptene, cyclohexene). The results of these experiments will be reported in the subsequent papers. |
