1.1- difluoroethylene derivatives

The same authors developed an original method of the synthesis of 1-(1,2,2,2-tetrafluoroethyl)-l,2,4-triazole 85 by treatment of N-(2-chloro-l,l,2-trifluoro)-1,2,4-triazole with tetramethylammonium fluoride [83]. The assumed reaction mechanism consist of several steps. In the first stage elimination of HF and the formation of 2-chloro-l,2-difluoroethylene derivative takes place. Further chlorine atom is replaced by fluorine with the formation of 1,2,2-trifluoroethylene-l,2.4-triazole. Finally addition of HF gave the final product 85. 

Cyclobutanes from the addition of 1-chloro-l-fluoroethylene to chlorotrifluoro- or tetrafluoro-ethylene, of 2-fluoropropene to tetrafluoroethylene, and of 1-chloro-2,2-difluoroethylene to vinyl fluoride or propene have been claimed to be anaesthetics. Diels-Alder addition of cyclopentadiene to acids of the type, trans-RpCHiCH COaH (Rf = CHaF, CHFa, CFs, C2F5, or n-CsFv) and a number of related esters and other derivatives, at 25 °C, results in predominant formation of adduct witii an endo fluoroalkyl group. The addition of cyclopentadiene to the 1,1-difluoroethylenes, CFalCFa, CFa CF CFs, CFa CCla, CFa C(CF3)2, CFaiCCl-CFaCl, and CFa.CFH has been recorded and the fiee-radical bromina-tion of the resulting norbomenes studied. Buta-1,3-diene and trifluorovinyl-sulphur pentafluoride yield essentially a mbcture of cis- and rmns-cyclobutanes (116), with little or no cyclohexene formation the olefin resembles perfluoropropene which yields ca. 5% of cyclohexene, in this respect. Perfluoroindene, which adds... 

The repeating unit is —CH2CF2— and the polymer is written -(-CH2CF2-)-n.The repeat unit is derived from 1,1-difluoroeth-ylene and the polymer is named poly(1,1-difluoroethylene).This polymer is used in microphone diaphragms. 

This reaction occurs readily under pressure at room temperature and has been successfully accomplished for tetrafluoroethylene, chlorotrifluoro-ethylene, and l,l-dichloro-2,2-difluoroethylene. HCF2CF2Mn(CO)s has also been synthesized by the decarbonylation of the acyl derivative HCF2 CF2COMn(CO)s 15J) Reaction of HMn(CO)5 with hexafluorobutyne-2 gives CF3CH=C(CF3)Mn(CO)s. 

Okuhara, K. Introduction and Extension of Ethynyl Group using l,l-dichloro-2,2-Difluoroethylene. A Convenient Route to Lithium Acetylides and Derived Acetylenic Compounds. J. Org. Chem. 41, 1487 (1976). 

Miscellaneous Fluoroalkenyl Derivatives Table IX). Seyferth and Wada 333) studied a number of di(substituent)difluoroethylene compounds prepared by reaction of (C2Hs)3SiCF CF2 with a variety of nucleophilic reagents. Although the authors did not attempt to assign the two F ... 

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