168558-18-7Relevant academic research and scientific papers
Domino Friedel-crafts-type cyclizations of difluoroalkenes promoted by the α-cation-stabilizing effect of fluorine: An efficient method for synthesizing angular PAHs
Fuchibe, Kohei,Jyono, Hideharu,Fujiwara, Masaki,Kudo, Takao,Yokota, Misaki,Ichikawa, Junji
scheme or table, p. 12175 - 12185 (2011/12/01)
In order to synthesize polycyclic aromatic hydrocarbons with nonlinear arrangements (angular PAHs), acid-promoted domino cyclizations of 1,1-difluoroalk-1-enes and 1,1-difluoroalka-1,3-dienes were studied. 1,1-Difluoroalkenes, each bearing two aryl substituents, were regioselectively protonated with FSO3H·SbF5 to generate fluorine-stabilized carbocations, which readily underwent domino Friedel-Crafts-type cyclizations to give carbocycles based on 6/n/m/6 ring systems (n,m=5-7) in good to high yields. Protonation of 1,1-difluoroalka-1,3- dienes took place at their electron-rich methylene (CH2) carbon atoms in the presence of milder acids such as camphorsulfonic acid and trifluoromethanesulfonic acid. Domino cyclizations of the resulting fluorine-stabilized allylic carbocations afford carbocycles based on 6/6/6/6 or 6/6/5/6 ring systems in high yields.
Synthesis of 1,1-difluoroalkenes via α,α-difluoro-β-lactones
Ocampo, Rogelio,Dolbier, William R.,Paredes, Rodrigo
, p. 41 - 50 (2007/10/03)
A new method for the general synthesis of 1,1-difluoroalkenes from ketones is presented.The procedure involves initial condensation of a ketone with the difluoro Reformatsky reagent, hydrolysis to form the α,α-difluoro-β-hydroxy acids, followed by cycliza
