First formation of 1,1-dihalo-1,3-butadienes from reactions of dichloro- and dibromocarbenes with cyclopropenes via new addition-rearrangements

Article abstract of DOI:10.1016/S0040-4039(00)61306-0

New dichloro- and dibromocarbene addition-rearrangements are reported. In the reactions of 1,2-diarylcyclopropenes with difluoro-, dichloro-, dibromo-, and bromofluorocarbene, 2,3-diaryl-1,1-dihalo-1,3-butadienes are formed. In addition, 1,3-diaryl-2,3-dihalocyclo-1-butenes are formed. For the formation of the 1,1-dihalobutadienes, new addition-rearrangement mechanisms are proposed. Furthermore, some reactions of cyclobutenes with dihalocarbenes are described.