126 Notizen

I(E)-l,2-Difluoro-2-(pentafluoro- Discussion A6-sulfanyl)ethenyl|phosphonates We have found that organic phosphites (la and Holger Wessolowskia, Gerd-Volker lb) will react with l,2,2-trifluoro-l-(pentafluoro- >„6-sulfanyl)ethylene (2) [5] to give the first F5S Röschenthaler*-3, Rolf Winterb, and group containing alkenylphosphonates, 4 a, b, Gary L. G ard*b [1] which are moisture-sensitive colorless liquids a Institut für Anorganische und Physikalische (Scheme 1). The (E) isomers exclusively were found, Chemie der Universität Bremen, Leobener Straße, D-2800 Bremen 33, F.R.G. derived from the intermediates 3 a, b in which there b Department of Chemistry, Portland State is maximum repulsion between the phosphonium University, Portland, Oregon 97207, U.S.A. and sulfanyl groupings [4], The 70 eV El mass spec­ Z. Naturforsch. 46b, 126-128(1991); tra show no parent molecular ion, but for 4 a the ion received June 15, 1990 [M + 1]+ was found; this has been observed in a few cases, for similar compounds [ 6]. For 4b the 1,2,2-T rifluoro-1 -(pentafluoro-A6-sulfanyl)- ethylene, Silylated Phosphites, Phosphonates [M -CH 3]+ fragment was obtained in keeping with results reported for O-trimethylsilylated phos­ For the first time SF5 containing organic phos­ 3)2 phonates, SF5CF = CFP(0)(0R')2 have been phonates, e.g. for CF3CF = CFP(0)(0SiMe [7], prepared from trimethylsilylphosphites, In the IR spectra, substitution of one fluorine (R'0)2P0SiMe, (R1 = Et, R1 = SiMe,) and atom in 2 by the phosphonate groupings decreases trifluorovinylsulfur pentafluoride, SF5CF = CF2 considerably (as expected) the C=C stretching fre­ in an Arbuzov type reaction. quency [ 8]; v = 1782 (2) versus 1666 (4 a) and 1665 cm-1 (4b). The same trend [4] was found for CF3C F= C F 2 and C F 3CF=CFP(0)(0R')2; v = Introduction 1797 versus 1672 (R 1 = Et) and 1673 cm “ 1 (R 1 = Trialkylphosphites (R '0)3P react with perfluori- SiMe3). However, stretching and deformation nated alkenes, e.g. C F 3C(R2) = CF 2 furnishing the modes of the F5S moiety remain uneffected. The phosphonates CF 3C(R2) = C F P (0 )(0 R 1)2 (R 1 = presence of (E) isomers is proven by the trans F - F Et, /Pr; R: = F, CF3) and alkylfluorides R'F via an coupling [J = 136.6 Hz (4a), 138.6 Hz (4b) Arbuzov type reaction [2]. The use of trimethyl­ (see Table I)] obtained from the l 9F-NMR spectra. silylphosphites (R '0) 2P0SiM e3 (la: R 1 = Et, lb: By comparison, the respective values for R 1 = SiMe3) is advantageous because of its greater (Z)-CF3CF = CFP(0)(0R 1)2 are 147.0 and nucleophilicity and easy formation of fluorotri- 144.0 Hz [4]. The introduction of the (R '0) 2P(0) methylsilane [3]. It was of interest to determine group in SF5CF = CF 2 causes a large high field shift whether an olefin containing the SF 5 group would (ca. 50 ppm) for the F 4 nucleus whereas a 25 ppm undergo reaction with organic phosphites. There downfield shift is observed for F 3 [9], The same are no reports in the literature of organo- trend can be found with CF3CF = CF 2 and phosphorus compounds containing an SF 5 group. CF3CF=CFP(0)(0R ')2 [4, 10]. Additional fine

FcS F.. I ^ F ^ S = ( /OR' M Y o ,

3 a,b A a.b

Scheme 1 R 1

a Et * Reprint requests to Prof. Dr. G.-V. Röschenthaler and to Prof. Dr. G. L. Gard b SiMe3 Verlag der Zeitschrift für Naturforschung. D-7400 Tübingen 0932-0776/91/0100-0126/SO 1.00/0 Notizen 127

Table I. 'H, 19F and 31P NMR data for 4 a

structure (quintuplet) is induced in the resonances temp, within 6 h and then stirred magnetically for of F 4 and phosphorus by the coupling with four 4 d at 60 °C. After distillation at 38 °C/0.04Torr c/s-F2 nuclei of the F5S group. The multiplet sig­ 2.2 g (79%) of a colorless liquid was obtained. nals of F 1 and F 2 experience a small highfield shift MS: m /z (%) = 327 (<1) [M + + H], 325 (<1) with respect to F5SCF = CF 2 [9]. [M + -H ], 283 (14) [M + + H -O C ,H 4], 271 (64) It is interesting to note that the F5S and F3C [M + + H -2 C ,H 4], 199 (4) [M + -S F 5], 171 (44) groups obviously have a similar influence on phos­ [M + -C ,H 4- S F 5], 143 (37) [M + -2 C ,H 4- S F 5], 127 phorus in the phosphonates XCF = CFP(0)(0R1)-, (14) [SF5+], 121 (48) [P(OC,H 5)V], 93 (56) (R 1 = Et, X = SF5: öp = -1.7, R 1 = Et, X = CF3: [P(OH)OC2H 5+], 65 (97) [P(ÖH)2+], 45 (37) 0P = 3.0; R 1 - SiMe3, X = SF5: 0P = -22.1, R 1 = [OC-,H5+], 29 (100) [C->H5+] and other fragments. SiMe3, X = CF3: 3p = -20.7). IR: v = 2995 cm “ 1 s‘(CH), 1666 w(C = C), 1300 vs (CF), 1258 s (CF, P=0), 1026 vs (P-O -C ), 871 vs (SF), 604 s (SF) and other absorptions. Experimental C6H l0F 7O3PS (326.17) The appropriate precautions in handling mois­ Calcd C 22.09 H 3.09 F 40.8 P 9.50, ture and oxygen-sensitive compounds were ob­ Found C 22.26 H3.16 F 40.4 P 9.68. served throughout this work. The reactions were carried out in a 100 ml heavy-wall glass tube, fitted Bis (trimethylsilyl) [ ( E)-l ,2-difluoro-2- (penta- with a TEFLON® stopcock. At —196 C com­ fluoro-X6-sulfanyl) ethenyl]phosphonate (4 b) pound 2 was condensed to 1 by using a vacuum The mixture of 2.9 g (9.6 mmol) of lb and 2.0 g line. After completion of the reaction the tube was (9.6 mmol) of 2 was allowed to warm up within 6 h opened in vacuo at -196 °C, and fluorotrimethyl- and stirred magnetically for 16 h at 5 °C. After dis­ silane and excess of 2 were removed at 0 C by tillation at 72 °C/0.1 Torr 3.2 g (81%) of a color­ pumping. The crude products were distilled. less liquid was obtained. Elemental analyses: Mikroanalytisches Labora­ MS: m /z (%) = 399 (89) [M+- C H 3], 287 (19) torium Beller, Göttingen. - MS: MAT 8222 spec­ (M + -S F 5], 229 (11) [FC = CFP(0)(0M e)0SiM e3+], trometer (EI-ionization, electron energy 70 eV; 151 (12) [P(OMe)(OSiMe3)+], 135 (11) GC/MS inlet system, inlet temperature 270 C). [P(OMe)OSi(CH,)Me+], 121 (9) [HP(OSiMe3)+], IR: Nicolet 5 DX FT spectrometer, spectra were 89 (11) [OSiMe3+], 77 (45) [P (0)0C H 2+] and other recorded of liquid films between sodium chloride fragments. plates (intensity: vs = very strong, s = strong, m = IR: v = 2966 cm -1 s (CH), 1665 m, broad medium, w = weak). (C = C), 1264 vs (CF, P = 0 ), 1201 vs (CF), 955 s NMR: AC 80 Bruker spectrometer, operating at (P-O-Si), 871 vs, broad (SF), 604 m (SF) and 80.13 MHz ('H, internal standard TMS), other absorptions. 75.39 MHz (l 9F, internal standard CC13F), and 32.44 MHz (31P, external standard 85% H 3P 0 4). C8H 18F 70 3PSSi2 (414.43) Compounds 1 and 2 were synthesized by literature Calcd C 23.18 H 4.38 F32.1 P 7.48, procedures [3, 5]. Found C 23.23 H 4.52 F31.9 P 7.56. The authors are grateful to the Fonds der Chemischen Diethyl [ ( E )-l ,2-difluoro-2- (pent afluoro- Industrie for financial support. G. L. G. and R. W. ex­ X6-sulfanyl)ethenylJphosphonate (4 a) press their appreciation to the U.S. Department of Ener­ gy (DE-FG 21-88 MC 25142) for support of this work. The mixture of 1.8 g (8.7 mmol) of la and 2.0 g G. L. G. wishes to thank the Fulbright Commission for (9.6 mmol) of 2 was allowed to warm to room a Senior Fulbright Scholarship. 128 Notizen

[1] Senior Fulbright Fellow 1989/90 at the University of Spectrometry of Inorganic and Organometallic Bremen. Compounds, p. 408, Elsevier, Amsterdam - Lon­ [2] A. A. Kadyrov and E. M. Rokhlin, Usp. Khim. 57, don - New York (1973). 1488(1988). [7] U. von Allwörden and G.-V. Röschenthaler, [3] L. Wozniak and J. Chojnowski, Tetrahedron 45, Chem.-Ztg. 109,81 (1985). 2465(1989). [8] L. H. Cross. G. Cushing, and H. L. Roberts, Spec- [4] U. von Allwörden and G.-V. Röschenthaler, trochim. Acta 17, 344 (1961). Chem.-Ztg. 112, 69(1988). [9] N. Boden, J. Feeney, and L. H. Sutcliffe, Spectro- [5] J. Steward. L. Kegley, H. F. White, and G. L. Gard. chim. Acta 21, 627 (1965). J. Org. Chem. 34/760 (1969). [10] T. D. Coyle, S. L. Stafford, and F. G. A. Stone, [6] T. R. Spalding, in Litzow-Spalding (ed.): Mass Spectrochim. Acta 17, 1244 (1961).