Catalytic Activity of Pt(II) Complexes in Addition of Tetrachloromethane to Alkenes

摘要

The use of catalytic systems based on Cu(I) and Co(II) complexes for addition of tetrachloromethane to alkenes was reported previously;CC1_4,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 CC1_4:CC1_4:1-hexene=1.3:1.0.For example,when a 1:1:1 (by volume,at 25degC) mixture of CC1_4,1-hexene,and acetonitrile is heated to 67-140degC 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),dichloro-bis[tri(m-tolyl)phosphine] platinum(II),dimethylbis-(triphenylphosphine)platinum(II),diiodobis(triphenyl-phosphine)platinum(II),and other compounds.