Generation from chlorodifluoroacetates

Preparation.—It has been shown that the stability of the ylide solution formed from the reaction of dihalogenodifluoromethanes with tertiary phosphines is due to a dynamic equilibrium which lies on the side of phosphine and phosphonium salt (Scheme 1). Ylide solutions generated from chlorodifluoroacetate are unstable since no such equilibrium is possible.1... 

Precursor of difluorocarbene [before references]. In a study of the behavior of cholesterol to dihalocarbenes, a Syntex group6 found that dichlorocarbene does not add to the somewhat unreactive double bond of cholesterol but that the less bulky difluorocarbene, generated from sodium chlorodifluoroacetate, does add to give a difluorocyclopropane which was assigned the 5/3,6/3-orientation mainly on the basis... 

The generation of difluorocarbene has been the subject of intense investigation. Difluorocarbene has been successfully formed from a wide range of fluorinated precursors, including metal salts of chlorodifluoroacetic acid, methyl chlorodifluoroacetate, ethyl chlorodi-fluoroacetate, difluorodiiodomethane, " chlorodifluoromethane." " difiuorotris(trifluoro-methyl)-A -phosphane hexafluoropropylene oxide,tetrafluoroethylene... 

Slagel12 reports that the lithium salt of chlorodifluoroacetic acid is superior to the sodium salt for generation of difluorocarbene and difluoromethylenetriphenylphos-phorane. Thus the yield of 4,5-dicarbethoxy-l,l-difluoronorcarane from the lithium salt was 50.6% and from the sodium salt was 25.7%. 

Metal, Metalloidal, and Non-metal Fluoroacetates.— Fluorine Magnetic Resonance Studies.I.para-Substituted P-DifluorostyTeae [thepP-difluorostyrenesp-XC,H(-CH CFs (X — NMe OMe, Me, H, F, Cl, or CN) were obtained via the CF,Cl-CO,Na-Ph,P-aldehyde route]. Reaction of Difluorocarbene with 2-Benzylidenecyclohexanones to afford Phenylfluorofurans (CF2 generated via thermal decomposition of CF CI-COjNa). Cyclodecapentaene Derivatives (reaction of CF, from CFjCI-COjNa with 1,4,5,8-tetrahydronaphthalenes). Action of Sodimn and Lithium Chlorodifluoroacetates on... 

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