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Lithium bis((trifluoromethyl)sulfonyl)amide (1) reacts with S2O6F2 to form FS020N(S02CF3)2 (2). Reaction of 2 with KF results in the cleavage of the S-N bond with the concomitant formation of CF3S02F. The ease of electrophilic addition reactions of HN(S02CF3)2 (3) with CH2=CHF, CH2=CF2, and CHF=CF2 depends upon the hydrogen content of the olefin. Addition occurs in a unidirectional fashion according to Markovnikov's rule to form CH3CHFN(S02CF3)2 (4), CH3CF2N(S02CF3)2 (5), and CH2FCF2N(S02CF3)2 (6), respectively. Cleavage of the CF3-N bond in 5 by reaction with CsF leads to the formation of CH3CF3 in about 12% yield. The major product formed is CF3S02F. The reactivity of fluorine atoms of the difluoromethylene group of 5 is shown by its reaction with (CH3)3SiN(CH3)2 in the presence of CsF under mild conditions where CF3S02F, (CH3)3SiF, and CH3C [N(CH3)2]=NS02CF3 (7) are formed. AgN(S02CF3)2 is formed by the reaction of Ag2C03 with an aqueous solution of 3 and undergoes metathetical reactions readily with compounds containing active halogen atoms to introduce the N(SC>2CF3)2 group. Strong Lewis acids such as ZN(S02CF3)2 [Z = R3Sn, R = CH3 (8), H-C4H9 (9), and CeHs (10); Z = (CH3)3Si ( 11)] can thus be conveniently prepared. The vinyltin(IV) compound (CH3)3-SnCF=CF2 ( 12) is synthesized by the reaction between (CH3)3SnCl and CF2=CFBr in hexaethylphosphorus triamide and benzonitrile. Multinuclear NMR studies of the trialkylstannyl/silyl derivatives suggest a quasitetrahedral structure around the central silicon or tin atom as reflected by their very low 29Si (55.9 ppm) and u9Sn (~250 ppm) NMR chemical shifts and V(119Sn-13C) and 2/(119Sn-'H) coupling constants. Compounds 8,9, and 11 can also be isolated by reaction of C1N(S02CF3)2 ( 13) with the respective alkylmetal chlorides in a noncoordinating solvent. However, 13 fails to add across the perfluorovinyl group in CF2=CFSn(CH3)3 ( 12) and forms CF2=CFC1 1and 8 instead. Reactions of 13 with a variety of per/polyfluoroolefins, such as CF2=CFX

At elevated temperatures, IV-chlorodifluoromethanimine (CF2=NC1) adds to perhaloalkenes of the type CF2=CFX, forming CF2=NCF2CFXC1 (X = F, Cl, Br) in good yields. Reaction of these butenes with trifluoromethyl hydroperoxide (CF3OOH) gives CF3OOCF2NHCF2CFXCl, and subsequent treatment with KHF2 forms the corresponding oxaziridine, 0CF2NCF2CFXC1, in excellent yield. Eight new compounds, along with the previously reported CF2=NCF2CF2C1, were characterized by their IR, NMR, and mass spectra and physical properties.The synthesis of l,l-difluoro-2-azaperhalo-l-alkenes or IV-(perhaloalkyl)difluoromethanimines of the type CF2= NRX is very difficult, and only a few such compounds are known. Examples have, in general, been prepared by pyrolysis of perfluoro tertiary amines and by the pyrolysis of perfluoro-2-alkyl-l,2-oxazetidines or the corresponding copolymer formed from RfNO and CF2=CF23 (eq 1-3). In 750 °C (C2F5)3N-* C2F5N=CF2 + fluorocarbons (1) C2F5N -0 550 °C cf2-cf2 c2f5n = cf2 + cof2 (2) c2f5 -(-N-0-CF2CF2 450 C2F5N=CF2 t C0F2 (3) the case of perfluoro-2-azapropene, more practical methods of synthesis have been developed by utilizing (CF3)2NC-(O)F, available from electrochemical fluorination of (C-H3)2NC(0)F,4 or C13CN=CC12 from high-temperature chlorination of (CH3)2NC(0)C15 (eq 4-7). (CF3)2NC(0)F 575 °C> CF3N=CF2 + COF2 (4) (CH3)2NC(0)C1 CI2, hv CI2, carbon C1,CN=CC12 120°C 200

Some reactions of jV-chlorodifluoromethanimine, CF2=NC1, have been studied and are compared to related reactions of perfluoromethanimine, CF2=NF. Fluoride promoted reactions of CF2=NC1 result in evidence for the CF3NCT anion, which is thermally less stable and less reactive than CF3NF". Oxidation of CF3NCT, formed in situ by reaction of CF2=NC1 with KF or CsF, with Cl2 forms CF3NC12. With Br2, CF3NBrCl is formed along with CF3NBr2. The latter arises from a novel fluoride-catalyzed conversion of CF3NBrCl to CF3NBr2 by Br2, and the same products can be obtained starting with CF3NC12, Br2, and MF. Extension of this reaction to C2F5NC12 and C3F7NC12 is also discussed. Addition of XOS02F (X = Cl, Br) to CF2=NC1 forms the novel diazene FS020CF2N=NCF20S02F, presumably via the intermediate FS020CF2NC1X addition products. Competitive reaction of CF2=NF and CF2=NC1 with fluoride ion results in the preferential formation of CF3NF". Nucleophilic attack of the latter on CF2=NC1 forms the novel diaziridine CF3NCF2NC1, which can be reduced by Hg in trifluoroacetic acid to CF3NCF2NH. The mechanism for the formation of the diaziridines is discussed.

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