Preparation of .beta.,.beta.-difluoro-.alpha.-(trifluoromethyl)styrenes by palladium-catalyzed coupling of aryl iodides with pentafluoropropen-2-ylzinc reagent
摘要:
Substituted aromatic iodides are functionalized by pentafluoropropen-2-ylzinc, CF3C(ZnX)=CF2 (X = Br, I, or CF2=CCF3-), in the presence of Pd(PPh3)4 to give the corresponding arenes in good yields. This is particularly attractive for preparation of title styrenes substituted with groups such as -NO2 or CO2R, which are incompatible with organomagnesium reagents. The best yields of the title styrenes with electron-donating substituents were obtained in DMF. For electron-withdrawing substituents, the best results were achieved in triglyme. A correlation was observed between Hammett sigma constants and F-19 NMR chemical shifts (R = 0.93-0.99, n = 8) and 2J(F-F) coupling constants (R = 0.94, n = 8).
Reaction of crystalline fluoro olefins with bromine vapor
作者:Douglas G. Naae
DOI:10.1021/jo00430a023
日期:1977.5
Efficient One Step Procedure for the Synthesis of α-Trifluoromethylated Arylacetates
作者:In Howa Jeong、Tae Won Park、Bum Tae Kim
DOI:10.1080/00397919808007172
日期:1998.6
The reaction of beta,beta-difluoro-alpha-trifluoromethylstyrene derivatives 1 with 3 equiv. of sodium methoxide in acetonitrile at 25 degrees C afforded alpha-trifluoromethylated arylacetates 3 in good yields.