823-25-6Relevant articles and documents
O-Difluoromethylation of 1,3-diones with S-difluoromethyl sulfonium salt
Yue, Chun-Bo,Lin, Jin-Hong,Cai, Ji,Zhang, Cheng-Pan,Zhao, Gang,Xiao, Ji-Chang,Li, HengFeng
, p. 35705 - 35708 (2016/05/19)
The O-difluoromethylation of 1,3-diones with S-difluoromethyl sulfonium salt is described. The sulfonium salt was previously believed to be a direct difluoromethylation reagent, but our mechanistic investigation reveals that the O-difluoromethylation reaction proceeds not only via the direct transfer of the CF2H group, but also via a difluorocarbene process. This work represents the first protocol for mild O-difluoromethylation of acyclic 1,3-diones.
Ylide-Carbene Chemistry. Synthesis of 1,1-Difluoro-1-alkenes
Wheaton, Gregory A.,Burton, Donald J.
, p. 917 - 927 (2007/10/02)
The reaction between nonstabilized alkylidenetriphenylphosphoranes and chlorodifluoromethane has been found to be a useful alternative to the Wittig reaction for the synthesis of many difluoromethylene olefins.Both primary and secondary ylides which do not contain strongly electron-withdrawing substituents within the alkylidene portion of the ylide react with chlorodifluoromethane to give the corresponding difluoromethylene olefins in yields which are significantly better than those obtained by the Wittig reaction.The formation of triphenylphosphine oxide is avoided, and all phosphorus-containing moieties can be recovered and recycled.The reaction proceeds by initial dehydrochlorination of chlorodifluoromethane by the ylide to generate difluorocarbene.The intermediate difluorocarbene is then trapped by a second equivalent of the nucleophilic ylide.Mechanistic evidence indicates that either a zwitterionic intermediate or a three-membered cyclic phosphorane can account for the 1,1-difluoro-1-alkene products.The isolation of several 1-hydro-1-fluoro-1-alkene products such as FCH=CHPh, FHC=CPh2, and FHC=CHCH=CHPh after steam distillation of the reaction mixtures, however, can only be accounted for via a three-membered cyclic phosphorane.
Bis(trifluoromethyl)cadmium*glyme (glyme = dimethoxyethane), a New, Powerful Fluoroalkylating Agent and Low-temperature Source of Difluorocarbene
Krause, Larry J.,Morrison, John A.
, p. 671 - 672 (2007/10/02)
The newly isolated reagent (CF3)2Cd*glyme readily exchanges ligands with, e.g., GeI4, SnI4, or PI3 to form the fully substituted compounds (CF3)4Ge, (CF3)4Sn, or (CF3)3P, within minutes at ambient temperature; reactions with acyl halides, like MeC(O)Br, form the acyl fluorides, like MeC(O)F, in excellent yields, 95percent, at -25 deg C and extrusion of CF2 at -25 deg C in this reaction is indicated by the formation of the expected difluorocyclopopane from tetramethylethylene in 53percent yield.
