NUCLEOPHILIC-SUBSTITUTION IN 1-SUBSTITUTED 3-IODOBICYCLO[1.1.1]PENTANES - A NEW SYNTHETIC ROUTE TO FUNCTIONALIZED BICYCLO[1.1.1]PENTANE DERIVATIVES

Nucleophilic substitution of the iodine in 1-substituted 3-iodobicyclo[1.1.1]pentanes [R = I (1), CF3 (2)] was investigated. The results of the reaction are strongly dependent on the nature of the nucleophile and the substituent. Whereas the trifluoromethyl derivative 2 is found to be inert in the reactions and gave substitution products only with organolithium reagents, the 1,3-diiodide 1 is much more reactive and affords normal substitution products with nitrogen bases and MeONa but gives [1.1.1]propellane with Grignard and organolithium reagents and with triaryl(alkyl)phosphines. Other synthesized 3-iodobicyclo[1.1.1]pentanes did not give substitution products. A general scheme for the transformations of 1 is also proposed.