Alpha-bromo-alpha,alpha-difluoroallyl derivatives as synthetic intermediate: nucleophilic substitution of alpha-bromo-alpha,alpha-difluoroallyl derivatives in the presence of palladium catalysts.
The palladium catalyzed nucleophilic substitution of alpha-bromo-alpha,alpha-difluoroallyl derivatives turned out to be an efficient method for the preparation of several fluorinated organic molecules. Several soft carbon nucleophiles regioselectively reacted with 3-bromo-3,3-difluoropropene (BDFP) to give the 3-substituted 1,1-difluoroalkenes. Phenylzinc chloride and tributylphenyltin afforded 1-fluoro-1,3-diphenylpropene. The radical bromination of 3-substituted 1,1-difluoroalkenes provided 1-substituted BDFPs, and a 1-substituted BDFP reacted with carbon nucleophiles to give 1,3-disubstituted 3,3-difluoroalkenes. For the reaction of nitrogen nucleophiles with BDFP, an amine and the sodium salts of the carbamates reacted with BDFP at the gamma-position. However, the sodium salts of the sulfoneamide predominantly attacked at the alpha-position.
Kirihara
M
M
Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, Sugitani, Japan. kirihara@ms.toyama-mpu.ac.jp
Takuwa
T
T
Okumura
M
M
Wakikawa
T
T
Takahata
H
H
Momose
T
T
Takeuchi
Y
Y
Nemoto
H
H
D002384:Catalysis; D017611:Fluorine Compounds / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010165:Palladium / Q000737:chemistry*
D017611:Fluorine Compounds; D010165:Palladium