679-69-6Relevant articles and documents
Rearrangement of 3-membered 1,1,2-trifluorobromonium and iodonium ions and comparison of trifluorochloronium to fluorocarbenium ions
Shellhamer, Dale F.,Davenport, Kevyn J.,Forberg, Heidi K.,Herrick, Matthew P.,Jones, Rachel N.,Rodriguez, Sean J.,Sanabria, Sunamita,Trager, Nicole N.,Weiss, Ryan J.,Heasley, Victor L.,Boatz, Jerry A.
, p. 4532 - 4538 (2008/09/20)
(Chemical Equation Presented) Reactions of chlorine (Cl2) with 4-halo-1,1,2-trifluorobut-1-enes (1, 2, or 3) give open-ion intermediates A and E that are in equilibrium. The open-chloronium ions (E) rearrange to a five-membered-ring halonium ion during ionic chlorination of 3 when the number-4 halo-substituent is iodine. Three-membered-ring bromonium and iodonium ions from alkenes 1, 2, or 3 are rather symmetrical and similar in structure. Quantum chemical calculations show that five-membered-ring halonium ion intermediates are 11 to 27 kcal/mol more stable than the three-membered-ring halonium ions or the open-ions A and E. The five-membered-ring intermediates lead to rearranged products. Rearranged products increase as the number-4 halogen (Z) becomes more nucleophilic (Z: Cl Br I). Open chloronium ions from ionic chlorination of terminal fluorovinyl alkenes are compared to the open ions generated by protons to similar alkenes.