35386-39-1Relevant academic research and scientific papers
Synthetic and mechanistic aspects of the reactions between bromodifluoromethyltriphenylphosphonium bromide and dibromofluoromethyltriphenylphosphonium bromide and trialkylphosphites
Flynn, Richard M.,Burton, Donald J.,Wiemers, Denise M.
, p. 583 - 589 (2008/12/22)
Bromofluoromethyltriphenylphosphonium bromides react with trialkylphosphites in two distinct ways. Bromodifluoromethyltriphenylphosphonium bromide undergoes a rapid exchange reaction with trialkylphosphites to give the corresponding bromodifluoromethylphosphonates in good to excellent yields. A similar exchange reaction also occurred with an analogous diethoxyphenylphosphonite to give the corresponding ethoxyphenylphosphinate. Mechanistically, the exchange process involves the formation of difluorocarbene via dissociation of the intermediate difluoromethylene ylide, capture of the difluorocarbene by the trialkylphosphite to give [ (RO)3 over(P, +) C over(F2, -) ], which captures bromine followed by dealkylation to the product, bromodifluoromethylphosphonate. The equilibria involved in the multi-step mechanism are all shifted to the phosphonate product by the final dealkylation step. In contrast, the dibromofluoromethyltriphenylphosphonium bromide does not under exchange reactions with trialkylphosphite. The phosphite serves as a halophilic reagent to abstract Br from the dibromofluoromethylphosphonium salt to generate the bromofluoromethylene ylide, which can easily be trapped in situ with aldehydes or ketones to give good yields of the E/Z-bromofluoroalkenes. No dissociation of the bromofluoromethylene ylide was observed.
PREPARATION AND SYNTHETIC UTILITY OF FLUORINATED PHOSPHONIUM SALTS, BISPHOSPHONIUM SALTS AND PHOSPHORANIUM SALTS
Burton, Donald J.
, p. 339 - 358 (2007/10/02)
The reaction of tertiary phosphines with fluorohalomethanes provides a rapid and high yield synthesis of various types of fluorinated phosphonium salts, bis-phosphonium salts and phosphoranium salts.These salts are useful precursors to fluorine-containing
