Addition of CCl4 to unsaturated compounds catalyzed by M3(CO)12 (M=Fe, Ru, Os)

The addition of CCl4 to hex-1-ene and to the methyl ester ofN-(trans-cinnamoyl)-l-proline (2) catalyzed by M3(CO)12 or by the M3(CO)12+DMF system (M=Fe, Ru, Os) was studied. The use of ruthenium and osmium dodecacarbonyls in combination with DMF increases the yields of adducts CCl3CH2CHClC4H9 (4) and PhCHClCH(CCl3)C(O)R′ (3) over those obtained in reactions catalyzed by the same carbonyls without DMF. In addition to adduct3, salts [M(CO3)Cl3]−[Me2NH2]+ were isolated from the products of the reaction between CCl4 and1 in the presence of M3(CO)12+DMF (M=Ru, Os). These salts do not catalyze this reaction and apparently result from chain termination. Experimental results in favor of a coordination mechanism of the addition of CCl4 to olefins in the presence of Ru3(CO)12 and Os3(CO)12 were obtained.