Polyhalogenoheterocyclic compounds. Part 36. Additions of diazomethane to perfluoropolyalkylethenes. A frontier orbital rationalisation of reactions of fluorinated alkenes with 1,3-dipoles and nucleophiles

Abstract

Additions of diazomethane to fluorinated alkenes have established the reactivity order (R_F)₂CC(R_F)₂ > (R_F)₂CCFRF (R_F)₂CCF₂, R_FCFCFR_F(R_F= perfluoroalkyl). Highly regioselective addition occurs with the carbon of the dipole becoming attached preferentially to the site in the alkene most susceptible to nucleophilic attack. An approach based on considering frontier orbitals (F.O.) leads to a model for reactivity towards diazomethane in these systems. Also, consideration of F.O. is suggested as an alternative approach to accounting for reactions involving nucleophilic attack on fluorinated alkenes.