Fluorines on vinylic and allylic positions are highly versatile substituents. Among the compounds bearing those fluorines, 1,1-difluoro-1-alkenes and 2-trifluoromethyl-1-alkenes exhibit electrophilic character because of electronegative fluorine atoms. 1,1-Difluoro-1-alkenes undergo nucleophilic substitution at the vinylic carbon (CF2) to afford substituted monofluoroalkenes (SNV reaction). 2-Trifluoromethyl-1-alkenes also undergo nucleophilic substitution at the carbon ? to the fluorines to produce the corresponding 1,1-difluoro-1-alkenes (SN2'-type reaction). On the basis of these facts, we have succeeded in constructing furan-, pyrrole-, and pyrazole-related frameworks bearing a fluorine substituent or a difluoromethylene group on their rings. In these processes, the normally disfavored nucleophilic 5-endo-trig cyclizations were accomplished with heteroatom nucleophiles. The ring-fluorinated and -difluoromethylenated heterocycles thus obtained have been attracting a great deal of attention as physiologically active substances and functional materials. This presentation discloses conceptually new approaches to these heterocyclic compounds, whose reports to date were limited in spite of their utility and potential.

Construction of fluorinated heterocycles: Intramolecular substitution of vinylic and allylic fluorines

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.