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Organometallics 2010, 29, 5274–5282 DOI: 10.1021/om100376d
AlCl3-Catalyzed Hydrosilylation of Alkynes with Hydropolysilanes† Nobu Kato, Yusuke Tamura, Taigo Kashiwabara, Takanobu Sanji, and Masato Tanaka* Chemical Resources Laboratory, Tokyo Institute of Technology, Nagatsuta, Midori-ku,Yokohama 226-8503, Japan Received April 30, 2010
AlCl3 catalyzes addition reactions of hydrooligosilanes (H(SiMe2)nR; n = 2-4, R = H, Me, Ph) with 1-decyne and other alkynes under mild conditions. In most reactions the Si-Si bonds remain intact to form anticipated products in fair to excellent yields, although Si-Ph bonds appear to be cleaved partially under the conditions. Arylethynes tend to form abnormal products due to Si-Si bond scission, but at a low temperature, the addition reaction proceeds normally. The reaction of 1,2-dihydrotetramethyldisilane with 1-decyne furnishes 1,2-didecenyldisilane, 1,3-didecenyltrisilane, and other byproducts at 0 °C, while the reaction run at a lower temperature proceeds cleanly. 1,3-Dihydrohexamethyltrisilane reacts more cleanly even at 0 °C. The reaction of pentamethyldisilane with 1,6-heptadiyne proceeds in a different direction, leading to cyclization. 1,7-Octadiyne reacts with 1,3-dihydrohexamethyltrisilane to give a polymeric material. The reaction of 1,2,3-trihydropentamethyltrisilane or poly(phenylsilylene) with 1-dectyne proceeds cleanly without perceptible Si-Si bond cleavage.
Introduction Hydrosilylation is a long-known reaction and is an indispensable tool to create a silicon-to-carbon bond.1 The majority of precedents deal with reactions with hydromonosilanes such as trichlorosilane, phenyldimethylsilane, trimethoxysilane, and diphenylsilane. As far as transition metal-catalyzed hydrosilylation is concerned, the reaction with a hydrooligosilane, † Part of the Dietmar Seyferth Festschrift. *To whom correspondence should be addressed. E-mail: m.tanaka@ res.titech.ac.jp. (1) Reviews: (a) Comprehensive Handbook on Hydrosilylation; Marciniec, B., Ed.; Pergamon Press: Oxford, 1992. (b) Ojima, I.; Li, Z.; Zhu, J. In The Chemistry of Organic Silicon Compounds; Rappoport, Z., Apeloig, Y., Eds.; John Wiley & Sons: New York, 1998; Vol. 2, Pt. 2, pp 1687-1792. (c) Hydrosilylation; Marciniec, B., Ed.; Advances in Silicon Science 1; Springer: Berlin, 2009. (2) (a) Sharma, H. K.; Pannell, K. H. Chem. Rev. 1995, 95, 1351. (b) Radical hydrosilylation of alkynes with hydrodisilanes was reported to proceed without deterioration of the Si-Si chain. See: Miura, K.; Oshima, K.; Utimoto, K. Bull. Chem. Soc. Jpn. 1993, 66, 2356. (3) (a) Yamamoto, K.; Kumada, M.; Nakajima, I.; Maeda, K.; Imaki, N. J. Organomet. Chem. 1968, 13, 329. (b) Tamao, K.; Asahara, M.; Kawachi, A. J. Organomet. Chem. 1996, 521, 325. (4) Urenovitch, J. V.; West, R. J. Organomet. Chem. 1965, 3, 138. (5) (a) Review: Jung, I. N.; Yoo, B. R. Adv. Organomet. Chem. 2005, 53, 41. (b) Finke, U.; Moretto, H. (to Bayer A.-G.) DE 1979-2804204A1; Chem. Abstr. 1979, 91, 193413x. (c) Oertle, K.; Wetter, H. Tetrahedron Lett. 1985, 26, 5511. (d) Anwar, S.; Davis, A. P. Tetrahedron 1988, 44, 3761. (e) Yamamoto, K.; Takemae, M. Synlett 1990, 259. (f) Sudo, T.; Asao, N.; Gevorgyan, V.; Yamamoto, Y. J. Org. Chem. 1999, 64, 2494. (g) Rubin, M.; Schwier, T.; Gevorgyan, V. J. Org. Chem. 2002, 67, 1936. (h) Song, Y.-S.; Yoo, B. R.; Lee, G.-H.; Jung., I. N. Organometallics 1999, 18, 3109. (i) Asao, N.; Yamamoto, Y. Bull. Chem. Soc. Jpn. 2000, 73, 1071. (j) Parks, D. J.; Blackwell, J. M.; Piers, W. E. J. Org. Chem. 2000, 65, 3090. (k) Dias, E. L.; Brookhart, M.; White, P. S. Chem. Commun. 2001, 423. (l) Asao, N.; Ohishi, T.; Sato, K.; Yamamoto, Y. Tetrahedron 2002, 58, 8195. (m) Roesler, R.; Har, B. J. N.; Piers, W. E. Organometallics 2002, 21, 4300. (n) Liu, Y.; Yamazaki, S.; Yamabe, S. J. Org. Chem. 2005, 70, 556. (o) Zipoli, F.; Bernasconi, M.; Laio, A. ChemPhysChem 2005, 6, 1772. See also: (p) Cyclization: Sudo, T.; Asao, N.; Yamamoto, Y. J. Org. Chem. 2000, 65, 8919. (q) Hydrogermylation: Schwier, T.; Gevorgyan, V. Org. Lett. 2005, 7, 5191.
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H(SiMe2)nR, has been believed to be a rather tough and intricate task due to the Si-Si bond cleavage,2 although very few successful examples have been encountered incidentally.3 For instance, Urenovitch and West reported long ago that attempted platinum-catalyzed reaction of 1-octene with pentamethyldisilane gave trimethylsilane and a trace of octyltrimethylsilane.4 Besides transition metal complexes, Lewis acids are also known to catalyze the hydrosilylation with hydromonosilanes.5 Rosenberg and co-workers have reported Lewis acid-catalyzed reactions of thiobenzophenone, thiols, phenols, thiophenols, aldehydes, and R-diketones with hydrodisilanes.6 However, Lewis acid-catalyzed reactions of hydrooligo- and hydropolysilanes with unsaturated carbon linkages have not been documented.7 This article discloses that AlCl3 is a capable catalyst to promote the addition of hydrooligosilanes and hydropolysilanes to alkynes without deterioration of the silicon chain under carefully tuned conditions. A possible side reaction, which we have to keep in mind beforehand, is skeletal rearrangement of Si-Si chains.8 In the present study, such a (6) (a) Harrison, D. J.; McDonald, R.; Rosenberg, L. Organometallics 2005, 24, 1398. (b) Harrison, D. J.; Edwards, D. R.; McDonald, R.; Rosenberg, L. Dalton Trans. 2008, 3401. (c) Skjel, M. K.; Houghton, A. Y.; Kirby, A. E.; Harrison, D. J.; McDonald, R.; Rosenberg, L. Org. Lett. 2010, 12, 376. (7) Lewis acid-mediated functionalization of surface Si-H bonds of porous silicon and related materials with alkenes or alkynes has been documented. The integrity of the local structure where the reaction took place is uncertain. (a) Buriak, J. M.; Allen, M. J. J. Am. Chem. Soc. 1998, 120, 1339. (b) Holland, J. M.; Stewart, M. P.; Allen, M. J.; Buriak, J. M. J. Solid State Chem. 1999, 147, 251. (c) Nelles, J.; Sendor, D.; Ebbers, A.; Petrat, F. M.; Wiggers, H.; Schulz, C.; Simon, U. Colloid Polym. Sci. 2007, 285, 729. (8) (a) Ishikawa, M.; Kumada, M. J. Chem. Soc. D, Chem. Commun. 1970, 157. (b) Ishikawa, M.; Iyoda, J.; Ikeda, H.; Kotake, K.; Hashimoto, T.; Kumada, M. J. Am. Chem. Soc. 1981, 103, 4845. (c) Ishikawa, M.; Watanabe, M.; Iyoda, J.; Ikeda, H.; Kumada, M. Organometallics 1982, 1, 317. (d) Blinka, T. A.; West, R. Organometallics 1986, 5, 128. (e) Fischer, J.; Baumgartner, J.; Marschner, C. Science 2005, 310, 825. (f) Wagner, H.; Wallner, A.; Fischer, J.; Flock, M.; Baumgartner, J.; Marschner, C. Organometallics 2007, 26, 6704. See also: (g) Wagner, H.; Baumgartner, J.; M€uller, T.; Marschner, C. J. Am. Chem. Soc. 2009, 131, 5022. r 2010 American Chemical Society
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Organometallics, Vol. 29, No. 21, 2010
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Table 1. Reactions of Alkynes with Pentamethyldisilane 1aa conversionb entry
R1CtCR2 2 R1 =, R2 =
1 2 3-1 3-2c 4-1 4-2 4-3 4-4d 4-5e 5 6
2A, n-Bu, n-Bu 2B, Ph, Ph 2C, n-Oct, H 2C 2D, Ph, H 2D 2D 2D 2D 2E, Cl(CH2)3, H 2F, p-An, H
temp (°C), time (h) 0, 1 0, 1 0, 1 0, 1 0, 1 -14, 1 -42, 2 -42, 5 -42, 2 0, 1 0, 24
1
2
product; % GC yieldb (isolated yield)
100 100 100 91 100 100 94 100 91 100 69
100 85 100 99 100 100 100 90 99 100 49
(Z)-3aA; 94 (80), (E)-3aA; 5 (Z)-3aB; 80 (62) (Z)-3aC; 71 (44), r-3aC; 2 (Z)-3aC; 77 (Z)-3aD; 36 (29), 4; 13 (Z)-3aD 46, 4; 26 (Z)-3aD; 68, 4; 10 (Z)-3aD; 28, 4; 37 (31) (Z)-3aD; 70 (54), 4; 7 (Z)-3aE; 48f (43), r-3aE; 3f (Z)-3aF; 8, (E)-3aF; 7
a Reaction conditions: 1a (1.0 mmol), 2 (1.0 mmol), AlCl3 (10 mol %), CH2Cl2 1 mL, in a 25 mL reactor. b Determined by GC using n-dodecane as an internal standard. The figures in parentheses are isolated yields. c Run in toluene. d Run in 10 mL of CH2Cl2. e Run in 0.5 mL of CH2Cl2. f Determined by GC using n-octane as an internal standard.
Scheme 1
side reaction did proceed depending on the substrate, but could be readily minimized by tuning the conditions.
Results and Discussion Before commencement of the present study, we briefly examined the reaction of 1-decyne with triethylsilane according to the reported procedure.5f The results were not always consistent, which appeared to be associated with the purification procedure of AlCl3. After various attempts, we have come to a best method, which furnishes reproducible results not only in the foregoing reaction with triethylsilane but also in the reactions with hydrooligosilanes. We strongly advise to strictly adhere to the procedure given in the Experimental Section, somewhat detailed in Figure S1 in the Supporting Information. Reaction of Pentamethyldisilane with Alkynes. A trial reaction of pentamethyldisilane 1a with 5-decyne 2A was run under the standard conditions using AlCl3 (10 mol %) in dichloromethane at 0 °C for 1 h. The resulting mixture was analyzed by GC to reveal (Z)-5-pentamethyldisilanyl-5decene, (Z)-3aA, being formed in 94% yield. GC and GC-MS analyses suggested that an isomer, presumably (E)-3aA, was also formed in 5% yield. Evaporation afforded a nearly pure sample, which was further purified by column chromatography to furnish (Z)-3aA as a colorless oil in 80% yield. Similar reactions of other acetylenes are summarized in Table 1. Diphenylacetylene 2B also reacted fairly well to form (Z)-3aB in 80% GC (62% isolated) yield. Unlike the reaction of 5-decyne, the E-isomer was not detected in the reaction mixture. The reactions of terminal acetylenes, on the other hand, were somewhat complex. Thus, 1-decyne 2C formed (Z)-1-pentamethyldisilanyl-1-decene, (Z)-3aC, in 71% GC yield. GC analysis
Scheme 2
of the mixture showed two other products were also formed. One of these, formed in 2% yield, was a branched one, 2-pentamethyldisilanyl-1-decene, r-3aC, the structure of which was confirmed by comparison with an authentic sample prepared via a separate route. The other, which was formed in 98%, indicating unsatisfactory material balance. GC analysis showed traces of many unidentified byproducts being formed. We presume that these byproducts, at least in part, have come from the aryl-Si bond cleavage, which has been known to take place incidentally in AlCl3-catalyzed hydrosilylation.5f,h,13 Longer chained hydrooligosilanes react more neatly than shorter ones. Thus, similar reactions of 1-hydroheptamethyltrisilane (1c) and 1-hydrononamethyltetrasilane (1d) with 1-decyne (2C) afforded (Z)-1-heptamethyltrisilanyl-1-decene, (Z)3cC, and (Z)-1-nonamethyltetrasilanyl-1-decene, (Z)-3dC, in 88% (64% isolated) and 86% (75% isolated) GC yields, respectively. The reactions were clean, and only traces of byproducts were observed. In the former reaction, one of the byproducts
was (Z)-3dC, suggesting that rearrangement involving Si-Si bond scission had taken place to a minute extent. Reaction of r,ω-Dihydrooligosilanes. Unlike 1-hydrooligosilanes, R,ω-dihydrooligosilanes are tricky reagents to control the reactivity. When 1,2-dihydrotetramethyldisilane (1e) was allowed to react with 1-decyne (2C) (2.0 equiv) at 0 °C using AlCl3 (10 mol % relative to Si-H bond), the reaction proceeded somewhat slowly as compared with that with pentamethyldisilane. GC analysis after 4 h revealed 1,2-di[(Z)-1-decen-1-yl]tetramethyldisilane, (Z,Z)-8eC, being formed in only 11% GC yield (Scheme 6). Quite surprisingly, however, 1,3-di[(Z)-1-decen-1-yl]hexamethyltrisilane, (Z,Z)8fC, was also found to be formed in 12% GC yield. Besides these, GC and GC-MS analyses suggested the formation of other isomers of (Z,Z)-8eC and (Z,Z)-8fC, which were not isolated and thus were not fully characterized. However, we presume, in view of the formation of r-3aC in the reaction of 2C with 1a, that a major byproduct that displayed a peak (∼7% yield) just before (Z,Z)-8eC in the gas chromatogram would be the (Z),R-isomer of (Z,Z)-8eC (Chart 2). Other support for this isomer came from 1H NMR analysis of the crude mixture. Thus, the crude mixture obtained after routine workup, displayed, besides the main signals due to (Z,Z)-8eC, weak signals at 5.34-5.37 (m) and 5.75-5.78 (m), which agreed fairly well with the values for an authentic sample of r-3aC.14 GC-MS analysis also supported the structure (m/z 394 corresponding to [M]þ).15 As was the case for 1-hydrooligosilanes, 1e reacted more cleanly at a lower temperature (-42 °C) to give (Z,Z)-8eC in 82% GC (71% isolated) yield, and (Z,Z)-8fC was not formed in an appreciable quantity at this temperature, although traces of (Z),R- and R,R-isomers appeared to be formed. The reaction of 1,3-dihydrohexamethyltrisilane (1f) with 2C was somewhat slow (0 °C, 8 h) as compared with that of 1e and also formed both (Z,Z)-8eC and (Z,Z)-8fC in 3% and 70% GC yields (Scheme 7). GC analysis showed that isomers of (Z,Z)-8fC were also formed (approximately 20%), indicating that the reaction resembles the foregoing reaction of
(13) See also for well-established electrophile-induced desilylation at the aryl-Si bond, often catalyzed by AlCl3: (a) Bassindale, A. R.; Taylor, P. G. In The Chemistry of Organic Silicon Compounds; Patai, S., Rappoport, Z., Eds.; Wiley: Chichester, U.K., 1989; Part 2, pp 909-919. (b) Colvin, E. W. Arylsilanes. Silicon in Organic Synthesis; Butterworths: London, 1981; pp 125-133.
(14) The SiEt3 analogue of r-3aC displays corresponding 1H NMR signals at 5.28 (m) and 5.63 ppm. See: Takeuchi, R.; Tanouchi, N. J. Chem. Soc., Perkin Trans. 1 1994, 2909. (15) (Z),R- and R,R-isomers corresponding to (Z,Z)-8fC could have also been formed as byproduct, although we did not try to search for these.
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Organometallics, Vol. 29, No. 21, 2010 Scheme 7
Scheme 8
Scheme 9
1e, although the redistribution reaction resulting in the change in the number of silicon atoms in the product to form (Z,Z)-8eC was much less extensive.16 The reaction of p-di(1,1,2,2-tetramethyldisilanyl)benzene (1g) with 1-hexyne (2G) (0 °C) was slow and resulted in a complex mixture (Scheme 8). We were unable to conclude that the expected product was formed, although we found byproducts, which appeared, on the basis of GC-MS analysis, to be 1b, 1bG, and 1bG-(SiMe2)2H, in appreciable yields. As compared with the reaction starting with 1,1,2,2tetramethyl-2-phenyldisilane (1b), aryl-Si bond cleavage (vide supra) took place more extensively and caused the complexity of the reaction with 1g. The presence of two disilanyl groups in 1g, which makes the aromatic ring more
(16) We have encountered similar observations in transition metalcatalyzed reactions of R,ω-dihydrooligosilanes. Among R,ω-dihydrooligosilanes, 1,2-dihydrodisilanes undergo more extensive redistribution than longer chained congeners. Details will be reported separately. (17) Colvin, E. W. Silicon in Organic Synthesis; Butterworths: London, UK, 1981; Chapter 10. (18) Attempted cyclization of 1,5-hexadiyne (2I) with 1a (1 equiv relative to 2I) failed (0 °C, 24 h, in CH2Cl2, 10 mol % AlCl3). GC and GC-MS analyses suggested that only the adduct coming from simple addition at the two triple bonds appeared to be formed rather selectively. However, attempted purification of the crude mixture by distillation or column chromatography after routine workup afforded unidentified compounds, which hampered further characterization of the major product. Another reaction using 2 equiv of 1a also formed the same compound as the major product.
Kato et al. Scheme 10
electron-rich, may have induced higher reactivity of the aryl-Si bond toward protiodesilylation.17 Cyclization Reaction. Cyclization of 1,6-heptadiyne (2H) with 1a (4 equiv) proceeded at -10 °C to give product 9 in 76% GC (65% isolated) yield (Scheme 9). In another reaction run at 0 °C using 1 equiv of 1a, the yield decreased to 36% GC yield.18 An NOE experiment with product 9, which displayed a 6% enhancement of the alkenyl proton at 6.09 ppm upon irradiation of the terminal methylene proton at 5.27 ppm, confirmed the stereochemistry. The structure is basically the same as the product obtained from 2H and hydromonosilanes.5f,j Nicatalyzed reactions of 1,7-octadiyne with hydromonosilanes are known to afford cyclized products, albeit in a different direction. However, the catalyst system is unable to cyclize 1,6-heptadiyne with hydrosilanes.19 Extension to Polymer Synthesis. The foregoing procedures can be successfully extended to polymer synthesis. When 1,7octadiyne (2J) was treated with 1,3-dihydrohexamethyltrisilane (1f) (0.5 equiv) in the presence of AlCl3 (10 mol % relative to 2J) in CH2Cl2 at 0 °C for 65 h, cyclization did not appear to have proceeded, but a mixture of oligomeric and polymeric materials (poly-10fJ) was formed in a nearly quantitative yield (Scheme 10). GC analyses showed traces of two oligomeric products, one comprising 1f and 2J in a 1:1 ratio (GC-MS m/z 282) and the other in a 2:1 ratio (GC-MS m/z 458). Routine workup followed by reprecipitation by addition of methanol to a dichloromethane solution afforded oil (0.20 g) and solid (0.08 g) fractions, which were separated by centrifugation. GPC analysis of the solid revealed Mn=3.3 103 and Mw=2.1 104 (Mw/Mn=6.3). The 1H NMR spectrum of the solid fraction displayed two olefinic protons, at 5.47 (d) and 6.32 (dt), and CH2 protons ranging from 1.26 to 2.07 in addition to SiMe signals, supporting the structure of poly-10fJ.20 Besides these, a septet at 3.7 was seen while no singlet signal was observed evidently around 1.8 ppm, indicating that the structure of termini was Si-H, but not CtCH. UV analysis displayed λmax at 236 nm, reasonable for the σ,π-conjugated Si3 structure.21 The liquid fraction appeared to be a mixture of oligomeric and polymeric materials, but was too complex to characterize. (19) (a) Tamao, K.; Kobayashi, K.; Ito, Y. J. Am. Chem. Soc. 1989, 111, 6478. (b) Tamao, K.; Kobayashi, K.; Ito, Y. Synlett 1992, 539. (20) The intensity ratio of the olefinic and SiMe protons was approximately 3.6:18, indicating a deficiency of the olefinic proton for the structure of poly-10fJ. This may suggest that the material has a structural defect, which may have come from side reactions of an intermediary Si-CHdCH unit with Si-H, which could lead to crosslinking. However the 1H NMR spectrum does not permit us to propose detailed structures. (21) The λmax values for CH2dCH(SiMe2)3Me and Ph(SiMe2)3Ph reported are 237 and 243 nm, respectively, while those for H(SiMe2)3H and Me(SiMe2)3Me are 218 and 215 nm, respectively. See: Kumada, M.; Tamao, K. Adv. Organomet. Chem. 1968, 6, 19.
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Organometallics, Vol. 29, No. 21, 2010 Scheme 11a
a Determined by GC using n-octane as an internal standard. bThe figures in parentheses are isolated yields. cBased on 1h. d Isolated by GPC. eDetermined by GC using sym-tetrachroloethane as an internal standard.
Chart 3. Possible Structures of 11-IV
The reaction of poly(hydrosilylene)s is another approach to polymer synthesis. A trial reaction to look into the possibility was run using 1,2,3-trihydropentamethyltrisilane (1h) and 1-decyne (2C) (3 equiv) at 0 °C in the presence of AlCl3 (10 mol % relative to the trisilane). The reaction proceeded slowly. Analysis after 48 h by GC using n-octane as an internal standard revealed both starting materials remaining and formation of 11-I-11-III in a total of 68% (Scheme 11). On the basis of 1H NMR spectroscopy, material 11-II isolated appears to be an approximately 1:1 mixture of 11-II-a and 11-II-b. When the quantity of the catalyst was increased to 30 mol % (i.e., 10 mol % relative to each Si-H), the reaction proceeded faster and was complete in 3 h to give 11-III in 48% GC yield. Byproducts of shorter retention times were not observed. However, GPC analysis suggested formation of a higher molecular weight material, which was isolated by preparative GPC to give 93.2 mg of the higher molecular weight material 11-IV. Its 1H NMR spectrum displayed signals arising from SiMe (0.000.30 ppm) and olefinic CH (5.5 and 6.3 ppm) approximately in a 18.3:2.2 ratio, indicating that each trisilane linkage has approximately one decenyl group, which matches the structures exemplified in Chart 3. Thus, olefinic bonds generated in hydrosilylation of decyne 2C with 1h reacted further with remaining Si-H bonds in intermediates 11-I and 11-II. However, a more detailed structure of the polymer is uncertain at this stage.22 (22) The ratio of signal intensity of the methyl region of the octyl groups (0.86-0.9 ppm) and the olefinic C-H signals was 12.9:2.2, which did not match the structure illustrated in Chart 3. This may be due partly to overlapping of other signals arising from linkages such as RCHSi and RCH2Si. However we are unable to exclude the possibility that the material was contaminated with other octyl-rich polymeric materials.
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Scheme 12
Finally we ran a reaction of poly(phenylsilylene) (1i) (Mw= 2.70 103, Mw/Mn = 1.63 as analyzed by GPC with polystyrene standards) with 1-decyne (2C) (1 equiv relative to a SiHPh repeat unit in the polymer) at 0 °C in CH2Cl2 using AlCl3 (10 mol % relative to 1-decyne) for 26 h (Scheme 12). Routine workup gave product polymer 12 as a pale yellow oil. GPC analysis revealed Mw =4.26 103, Mw/Mn =1.74, suggesting that the polymer chain was modified by the reaction with 1-decyne. Although molecular weight estimation by GPC using polystyrene standards is not very reliable, the GCP analysis supports that chain scission has not taken place extensively. The degree of modification was analyzed by 1H NMR spectroscopy23 only for higher molecular weight fraction 120 (sticky oil, Mw =4.57 103, Mw/Mn =1.51), isolated by preparative GPC. Although the signals were all broad, estimation was made by comparison of signal intensities for Ph (6.0-8.1 ppm) and octyl chain (0.2-2.9 ppm) regions, which suggested that the degree of modification was 89%.
Conclusion This report demonstrates clearly that AlCl3 is a capable catalyst to promote hydrosilylation of alkynes, both terminal and internal, with hydrooligosilanes H(SiMe2)nR (n=2-4, R=H, Me, Ph) under mild conditions. Side reactions such as Si-Si bond cleavage and rearrangement proceed occasionally, but can be suppressed by tuning the reaction conditions. The reaction of H(SiMe2)2H with 1-decyne (at 0 °C) gave not only the Z,Z-adduct coming from the reaction at both termini of H(SiMe2)2H but also the corresponding trisilane adduct, but the latter is able to be minimized at -42 °C. H(SiMe2)3H reacts more cleanly even at 0 °C. Cyclization of 1,6-heptadiyne with H(SiMe2)2Me also proceeds cleanly to form a cyclohexene derivative. These hydrosilylation reactions are applicable to polymerization and modification of polysilanes such as H(SiMe2)SiMeH(SiMe2)2H and -(SiHPh)n-. We believe these results have furnished a somewhat detailed sketch of the landscape in the AlCl3catalyzed hydrosilylation to start with in future applications.
Experimental Section Purification of AlCl3. In order to secure the reproducibility of the AlCl3-catalyzed hydrosilylation, purification of AlCl3 should (23) Since silicon-containing polymers occasionally fail to give satisfactory elemental analysis due to difficulty of combustion, an estimate of the degree of modification by elemental analysis may be less reliable than that by 1H NMR spectroscopy.
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adhere strictly to the following procedure. Under a dry nitrogen atmosphere, AlCl3 was placed into a sublimation apparatus (glass tube or flask fitted with a coldfinger), and the apparatus was dipped into a hot oil bath set beforehand at 200 °C. After 1 h, the apparatus was transferred to a glovebox, and the white sublimate that condensed onto the coldfinger was collected and transferred to a Schlenk tube, which was stored in the glovebox. In each reaction, AlCl3 was weighed in the glovebox and placed into a reaction vessel (Schlenk tube). Somewhat detailed information of the apparatus is given as Figure S1 in the Supporting Information. Typical Procedure for AlCl3-Catalyzed Reactions of Alkynes with Hydropolysilanes: Reaction of 5-Decyne with Pentamethyldisilane, Forming (Z)-5-Pentamethyldisilanyl-5-decene. To AlCl3 (0.100 mmol) and dichloromethane (0.5 mL) placed in a Schlenk tube kept at 0 °C were added pentamethyldisilane (1a) (1.00 mmol) and a dichloromethane (0.5 mL) solution of 5-decyne (2A) (1.00 mmol). The mixture was stirred at that temperature for 1 h and was quenched with triethylamine (0.2 mL) and saturated aqueous NaHCO3 (1.0 mL). The organic phase was analyzed by GC after addition of n-dodecane as internal standard. After GC and GC-MS analyses, the mixture was separated, the aqueous phase was extracted with hexane (2 mL 4 times), and the combined organic phase was washed with brine (5 mL) and dried over sodium sulfate. The filtrate of the dried solution was evaporated to leave a nearly pure sample, which was further purified by column chromatography (silica gel, hexane) to give (Z)-3aA as a colorless oil in 80% yield. (Z)-5-Pentamethyldisilanyl-5-decene, (Z)-3aA. Colorless oil. 1 H NMR (CDCl3): δ 0.06 (s, 9H, SiMe3), 0.17 (s, 6H, SiMe2), 0.89 (t, 3JHCCH = 6.8 Hz, 3H, CH3), 0.90 (t, 3JHCCH = 6.8 Hz, 3H, CH3), 1.25-1.34 (m, 8H (CH2)2CH2C(Si)dCHCH2(CH2)2), 2.01 (t, 3JHCCH = 6.0 Hz, 2H, CH2CHdC(Si)CH2), 2.03 (d, 3JHCCH = 7.1 Hz, 2H, CH2CHdC(Si)CH2), 5.94 (t, 3JHCCH = 7.1 Hz, 1H, CH). 13C{1H} NMR (CDCl3): δ -2.46, -1.57, 14.04, 14.13, 22.50, 22.59, 32.54, 32.74, 33.33, 38.21, 138.09, 142.46. 29Si NMR (CDCl3) δ -26.09, -18.68. IR (neat, cm-1): 2954, 1610, 1457, 835, 800. GC-MS m/z (% relative intensity): 270 ([M]þ, 24), 197 ([M - SiMe3]þ, 100), 141 (30), 127 (46), 113 (32), 99 (31), 87 (12), 73 (45), 59 (11). Anal. Calcd for C15H34Si2: C, 66.58; H, 12.66. Found: C, 66.44; H, 12.50. (Z)-1-(Pentamethyldisilanyl)stilbene, (Z)-3aB. Colorless oil. 1 H NMR (CDCl3): δ -0.04 (s, 6H, SiMe2), 0.01 (s, 9H, SiMe3), 7.18-7.39 (m, 10H, 2Ph), 7.33 (s, 1H, CH). 13C{1H} NMR (CDCl3): δ -1.54, -1.46, 125.71, 127.16, 127.25, 127.92, 127.98, 128.62, 139.78, 144.84, 146.37, 147.62. 29Si NMR (CDCl3): δ -23.78, -17.88. IR (neat, cm-1): 3064, 2954, 1589, 1490, 833, 802. GC-MS m/z (% relative intensity): 310 ([M]þ, 4), 237 ([M SiMe3]þ, 100), 221 (15), 207 (3), 159 (22), 135 (34), 121 (7), 73 (4), 59 (7). Anal. Calcd for C19H26Si2: C, 73.48; H, 8.44. Found: C, 73.76; H, 8.57. (Z)-1-Pentamethyldisilanyl-1-decene, (Z)-3aC. Colorless oil. 1 H NMR (CDCl3): δ 0.06 (s, 9H, SiMe3), 0.16 (s, 6H, SiMe2), 0.88 (t, 3JHCCH = 6.4 Hz, 3H, CH3CH2), 1.28-1.36 (m, 12H, (CH2)6), 2.07 (dt, 3JHCCH =6.9 Hz, 3JHCCH =7.0 Hz, 2H, CH3(CH2)6CH2), 5.46 (d, 3JHCCH = 13.7 Hz, 1H, CH2CHdCHSiMe2), 6.32 (dt, 3JHCCH=13.7 Hz, 3JHCCH=7.0 Hz, 1H, (Si)CHd CHCH2). 13C{1H} NMR (CDCl3): δ -2.51, -2.06, 14.11, 22.68, 29.27, 29.47, 29.58, 29.90, 31.88, 34.24, 127.37, 149.10. 29Si NMR (CDCl3): δ -29.28, -18.30. IR (neat, cm-1): 2952, 2857, 1602, 1457, 725, 690. GC-MS m/z (% relative intensity): 270 ([M]þ, 7), 255 ([M - Me]þ, 7), 196 ([M - SiMe3 - 1]þ, 100), 181 ([M SiMe3 - Me - 1]þ, 20), 168 (18), 139 (15), 131 (9), 125 (16), 99 (33), 81 (14), 73 (61), 59 (26). HRMS (EI): calcd for C15H34Si2 m/z 270.2199, found 270.2200. Anal. Calcd for C15H34Si2: C, 66.58; H, 12.66. Found: C, 66.42; H, 12.68. (Z)-β-(Pentamethyldisilanyl)styrene, (Z)-3aD. This compound was isolated from entry 4-5 (Table 1). Colorless oil. 1H NMR (CDCl3): δ 0.03 (s, 9H, SiMe3), 0.11 (s, 6H, SiMe2), 5.85 (d, 3JHCCH =14.7 Hz, 1H, CHSiCH2), 7.23-7.34 (m, 5H, Ph), 7.37 (d, 3JHCCH=14.7 Hz, 1H, CHPh). 13C{1H} NMR (CDCl3):
Kato et al. δ -2.15, -1.83, 127.28, 127.93, 128.09, 131.74, 140.03, 146.17. 29 Si NMR (CDCl3): δ -27.89, -18.40. IR (neat, cm-1): 2952, 1594, 731, 694. GC-MS m/z (% relative intensity): 234 ([M]þ, 24), 161 ([M - SiMe3]þ, 100), 145 ([M - SiMe3 - Me - 1]þ, 74), 135 (26), 73 (25), 59 (5). HRMS (EI): calcd for C13H22Si2 m/z 234.1260, found 234.1256. 1-Phenyl-1-pentamethyldisilanyl-2-trimethylsilyl-2-dimethylsilylethane, 4. This compound was isolated from entry 4-4 (Table 1). Colorless oil, bp 60-75 °C/0.44 mmHg (Kugelrohr). 1H NMR (benzene-d6, 300 MHz): δ -0.01 (d, 3JHSiCH = 3.8 Hz, 3H, SiMeH), 0.01 (s, 9H, SiSiMe3), 0.02 (s, 9H, CSiMe3), 0.16 (d, 3 JHSiCH = 3.8 Hz, 3H, SiMeH), 0.26 (s, 3H, SiMeSiMe3), 0.29 (s, 3H, SiMeSiMe3), 0.60 (d, 3JHCCH = 1.5 Hz, 1H, CHSi2), 2.77 (d, 3JHCCH = 1.5 Hz, 1H, PhCH), 4.74 (sept, 3JHSiCH = 3.8 Hz, 1H, SiH), 6.99 (t, 3JHCCH = 7.4 Hz, 1H, p-Ph), 7.09 (m, 2H, mPh), 7.33 (d, 3JHCCH = 7.4 Hz, 2H, o-Ph). 13C{1H} NMR (benzene-d6, 75 MHz): δ -3.1, -2.6, -1.5 (3), -1.5 (9), -0.5, 1.1 (SiMe 6), 17.4 (PhCHC), 34.2 (PhC), 125.8, 128.4, 130.5, 144.8. 29Si NMR (CDCl3, 60 MHz): δ -18.8, -12.9, -10.8, 5.1. GC-MS (20 eV): m/z (% relative intensity) 366 ([M]þ, 6), 293 ([M - Me]þ, 100), 234 (61), 220 (20), 205 (14), 193 (19), 161 (95), 146 (16), 135 (22), 131 ([SiMe2SiMe3]þ, 71), 73 (18). HRMS (EI): calcd for C18H38Si4 m/z 366.2051, found 366.2057. (Z)-1-Pentamethyldisilanyl-5-chloro-1-pentene, (Z)-3aE. Colorless oil, bp 37-46 °C/0.38 mmHg (Kugelrohr). 1H NMR (CDCl3, 300 MHz): δ 0.07 (s, 9H, SiMe3), 0.18 (s, 6H, SiMe2), 1.86 (quint, 3JHCCH = 7.1 Hz, 2H, CH2CH2CH2), 2.23 (ddt, 3 JHCCH=7.1 Hz, 3JHCCH=7.1 Hz, 4JHCCCH=1.2 Hz, 2H, CH2CHd CH), 3.54 (t, 3JHCCH = 7.1 Hz, 2H, ClCH2), 5.55 (dt, 3JHCCH = 13.7 Hz, 4JHCCCH = 1.2 Hz, 1H, CHdCHSi), 6.28 (dt, 3JHCCH = 13.7 Hz, 3JHCCH = 7.1 Hz, 1H, CH2CHdCH). 13C{1H} NMR (CDCl3, 75 MHz): δ -2.6, -2.0, 31.3, 32.7, 44.5, 129.4, 146.4. 29Si NMR (CDCl3, 60 MHz): δ -28.9, -18.8. IR (neat, cm-1): 2993, 2952, 2895, 2844, 1604, 1444, 1398, 1246, 833, 802, 768, 725, 690. GCMS (20 eV): m/z (% relative intensity) 219 ([M - Me]þ, 2), 161 ([M - TMS]þ, 1), 126 (4), 111 (63), 98 (93), 93 (42), 83 (7), 73 ([TMS]þ, 100), 66 (5), 59 (10). HRMS (EI): calcd for C9H20ClSi2 (value for [M - Me]þ) m/z 219.0792, found 219.0790. (Z)-β-Pentamethyldisilanyl-p-methoxystyrene, (Z)-3aF. Colorless oil, bp 37.0-41.3 °C/0.053-0.068 mmHg (Kugelrohr). 1H NMR (C6D6, 300 MHz): δ 0.13 (s, 9H, SiMe3), 0.24 (s, 6H, SiMe2), 3.27 (s, CH3O), 5.83 (d, 3JHCCH=14.8 Hz, 1H, CdCHSi), 6.78 (d, 3 JHCCH = 8.48 Hz, 2H, phenylene o-protons with respect to methoxy), 7.27 (d, 3JHCCH=8.48 Hz, 2H, phenylene m-protons with respect to methoxy), 7.39 (d, 3JHCCH = 14.8 Hz, 1H, SiCd CH). 13C{1H} NMR (C6D6, 75 MHz): δ -1.7, -1.5, 54.8, 113.8, 129.2, 129.9, 133.1, 146.6, 159.8. 29Si NMR (C6D6, 60 MHz): δ -18.7, -28.2. IR (neat, cm-1): 3031, 3001, 2952, 2895, 2835, 1608, 1508 1464, 1442, 1417, 1302, 1253, 1173, 1111, 1038, 833, 802, 727, 690, 617, 586, 521. GC-MS m/z (% relative intensity): 264 ([M]þ, 33), 249 ([M - Me]þ, 68), 234 ([M - 2Me]þ, 11), 191 ([M TMS]þ, 100), 175 (79), 165 (76), 145 (32), 135 (16), 131 (Me3SiMe2Siþ, 10), 89 (13), 73 (72), 59 (56). HRMS (EI): calcd for C14H24OSi2 m/z 264.1366, found 264.1366. 1-tert-Butylphenyl-1-pentamethyldisilanyl-2-trimethylsilyl-2dimethylsilylethane, 40 . The reaction of p-tert-butylphenylacetylene (1.0 mmol) with 2 equiv of 1a was run using the typical procedure. Column chromatography (silica gel, gradient mixture of hexane with increasing portion of dichloromethane) afforded this product (166 mg, 40%). White prism, mp 48.9-50.2 °C. 1H NMR (benzene-d6, 300 MHz): δ 0.01-0.03 (m, 12H, SiMeH þ SiSiMe3), 0.06 (s, 9H, CSiMe3), 0.19 (d, 3JHSiCH = 3.7 Hz, 3H, SiMeH), 0.24 (s, 3H, SiMeSiMe3), 0.31 (s, 3H, SiMeSiMe3), 0.62 (br s, 1H, CHSi2), 2.80 (br s, 1H, PhCH), 4.80 (sept, 3JHSiCH = 3.7 Hz, 1H, SiH), 7.21 (d, 3JHCCH = 8.1 Hz, 2H, phenylene m-protons with respect to tBu), 7.34 (d, 3JHCCH = 8.1 Hz, 2H, phenylene o-protons with respect to tBu). 13C{1H} NMR (benzene-d6, 75 MHz): δ -3.1, -2.6, -1.6, -1.5, -0.5, 1.1 (SiMe 6), 17.2 (PhCHC), 31.5 (CMe3), 33.4 (PhC), 34.3 (CMe3) 125.2, 130.2, 141.6, 148.6. 29Si NMR (benzene-d6, 60 MHz): δ -18.9, -12.7, -10.8, 5.0. GC-MS
Article (20 eV): m/z (% relative intensity) 422 ([M]þ, 2), 349 ([M - TMS]þ, 100), 291 ([M - SiMe2SiMe3]þ, 57), 249 (24), 233 (84), 217 (41), 191 (52), 161 (17), 145 (34), 131 ([SiMe2SiMe3]þ, 20), 73 (34), 57 ([SiMe2H]þ, 77). HRMS (FAB, 2-nitrobenzyl alcohol): calcd for C22H45Si4 (value for [M - H]þ) m/z 421.2598, found 421.2593. (Z)-1-(2-Phenyl-1,1,2,2-tetramethydisilanyl)-1-decene, (Z)-3bC. Colorless oil, bp 92-105 °C/0.61 mmHg (Kugelrohr). 1H NMR (CDCl3, 300 MHz): δ 0.16 (s, 6H, SiMe2SiMe2Ph), 0.35 (s, 6H, SiMe2Ph), 0.89 (t, 3JHCCH = 6.6 Hz, 3H, CH3CH2), 1.22-1.41 (m, 12H, 6CH2), 1.95 (dt, 3JHCCH=7.1 Hz, 3JHCCH=7.1 Hz, 2H, CH2CHdCH), 5.44 (d, 3JHCCH=13.7 Hz, 1H, CHdCHSi), 6.31 (dt, 3JHCCH = 13.7 Hz, 3JHCCH =7.1 Hz, 1H, CH2CH=CH), 7.30-7.32 (m, 3H, o- and p-H), 7.44-7.47 (m, 2H, m-H). 13C{1H} NMR (CDCl3, 75 MHz): δ -3.7 -2.3, 14.1, 22.7, 29.3, 29.4, 29.5, 29.8, 31.9, 34.2, 126.7, 127.6, 128.3, 133.9, 139.6, 149.7. 29Si NMR (CDCl3, 60 MHz): δ -29.0, -21.2. IR (neat, cm-1): 3068, 3051, 2956, 2925, 2854, 1603, 1466, 1427, 1244, 1105, 831, 822, 795, 771, 731, 698, 648. GC-MS m/z (% relative intensity): 332 ([M]þ, 8), 317 ([M - Me]þ, 5), 259 (45), 197 (25), 135 (100), 121 (35), 99 (13), 73 (16), 59 (40). HRMS (FAB, 2-nitrobenzyl alcohol): calcd for C20H36Si2 m/z 332.2356, found 332.2355. (Z)-1-Heptamethyltrisilanyl-1-decene, (Z)-3cC. Colorless oil. 1 H NMR (CDCl3): δ 0.08 (s, 9H, SiMe3), 0.09 (s, 6H, SiMe2SiMe3), 0.20 (s, 6H, CdCHSiMe2), 0.88 (t, 3JHCCH = 6.7 Hz, 3H, CCH3), 1.35-1.53 (m, 12H, (CH2)6), 2.08 (dt, 3JHCCH = 7.0 Hz, 3JHCCH = 6.8 Hz, 2H, SiCHdCHCH2), 5.47 (d, 3JHCCH = 13.7 Hz, 1H, SiCHdCHCH2), 6.31 (dt, 3JHCCH = 7.0 Hz, 3 JHCCH = 13.7 Hz, 1H, SiCHdCHCH2). 13C{1H} NMR (CDCl3): δ -6.63, -1.49, -1.45, 14.12, 22.68, 29.28, 29.47, 29.58, 29.94, 31.88, 34.12, 127.73, 148.91. 29Si NMR (CDCl3): δ -47.67, -25.78, -15.58. IR (neat, cm-1): 2950, 1602, 1460, 725, 688. GC-MS m/z (% relative intensity): 328 ([M]þ, 10), 313 ([M - Me]þ, 3), 269 (5), 255 (10), 239 (4), 197(6), 181 (11), 155 (7), 141 (8), 131 ([SiMe2SiMe3]þ, 32), 116 ([SiMe2SiMe2]þ, 100), 99 (6), 73 (15), 59 (4). Anal. Calcd for C17H40Si3: C, 62.11; H, 12.26. Found: C, 61.92; H, 12.28. (Z)-1-Nonamethyltetrasilanyl-1-decene, (Z)-3dC. Colorless oil, bp 84-130 °C/0.56 mmHg (Kuhgelrohr). 1H NMR (CDCl3, 300 MHz): δ 0.08 (s, 9H, SiMe3), 0.11 (s, 6H, SiMe2), 0.13 (s, 6H, SiMe2), 0.21 (s, 6H, CHSiMe2), 0.88 (t, 3JHCCH = 6.4 Hz, 3H, CH3CH2), 1.22-1.41 (m, 12H, (CH2)6), 2.08 (dt, 3 JHCCH = 7.0 Hz, 3JHCCH = 7.0 Hz, 2H, CH2CHdCH), 5.47 (d, 3JHCCH = 13.7 Hz, 1H, CHdCHSi), 6.31 (dt, 3JHCCH = 13.7 Hz, 3JHCCH = 7.0 Hz, 1H, CH2CHdCH). 13C{1H} NMR (CDCl3, 75 MHz): δ -5.9, -5.4, -1.3, 14.1, 22.7, 29.3, 29.5, 29.6, 29.7, 29.9, 31.9, 34.1, 127.8, 149.0. 29Si NMR (CDCl3, 60 MHz): δ -44.4, -43.1, -24.9, -15.0. GC-MS m/z (% relative intensity): 386 ([M]þ, 15), 313 ([M - TMS]þ, 11), 238 (11), 189 ([M - SiMe2SiMe2SiMe3]þ, 30), 174 ([SiMe2SiMe2SiMe2]þ, 100), 159 (13), 141 (13), 131 ([SiMe2SiMe3]þ, 39), 129 (25), 117 (18), 99 (10), 73 ([TMS]þ, 76), 59 (34). Anal. Calcd for C19H42Si4: C, 58.98; H, 11.98. Found: C, 59.12; H, 12.00. 1,2-Di[(Z)-1-decen-1-yl]tetramethyldisilane, (Z,Z)-8eC. Colorless oil, bp 101-118 °C/0.11 mmHg (Kugelrohr). 1H NMR (CDCl3, 300 MHz): δ 0.18 (s, 12H, 2SiMe2), 0.88 (t, 3JHCCH = 6.4 Hz, 6H, 2CH3CH2), 1.22-1.41 (m, 24H, 12CH2), 2.07 (dt, 3 JHCCH = 7.2 Hz, 3JHCCH = 7.2 Hz, 4H, 2CH2CHdCH), 5.46 (d, 3JHCCH = 13.7 Hz, 2H, 2CHdCHSi), 6.32 (dt, 3JHCCH = 13.7 Hz, 3JHCCH = 7.2 Hz, 2H, 2CH2CHdCH). 13C{1H} NMR (CDCl3, 75 MHz): δ -2.1, 14.1, 22.7, 29.3, 29.5, 29.6, 29.9, 31.9, 34.2, 127.4, 149.2. 29Si NMR (CDCl3, 60 MHz): δ -28.7. GCMS m/z (% relative intensity): 394 ([M]þ, 3), 379 ([M - Me]þ, 2), 321 (43), 255 ([M - C10H19]þ, 10), 197 ([M/2]þ, 45), 181 (10), 141 (10), 116 ([Si2Me4]þ, 5), 111 (25), 99 (36), 73 ([TMS]þ, 46), 59 (100). Anal. Calcd for C24H50Si2: C, 73.01; H, 12.76. Found: C, 72.79; H, 12.59. 1,3-Di[(Z)-1-decen-1-yl]hexamethyltrisilane, (Z,Z)-8fC. 1H NMR (CDCl3, 300 MHz): δ 0.11 (s, 6H, SiMe2SiMe2SiMe2,), 0.20 (s, 12H, SiMe2SiMe2SiMe2), 0.88 (t, 3JHCCH = 6.6 Hz, 6H,
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2CH3CH2), 1.09-1.27 (m, 24H, 12CH2), 2.07 (apparent dt, JHCCH = 6.8 Hz, 3JHCCH = 6.9 Hz, 4H, 2CH2CHdCH), 5.46 (dt, 2JHCCH = 13.7 Hz, 4JHCCCH = 1.2 Hz, 2H, 2CHdCHSi), 6.31 (dt, 3JHCCH =13.8 Hz, 3JHCCH =6.9 Hz, 2H, 2CH2CHd CH). 13C{1H} NMR (CDCl3, 75 MHz): δ -6.1, -1.4, 14.1, 22.7, 29.3, 29.5, 29.6, 30.0, 31.9, 34.1, 127.8, 148.9. 29Si NMR (CDCl3, 60 MHz): δ -46.8, -25.5. GC-MS m/z (% relative intensity): 452 ([M]þ, 8), 393 (6), 379 (12), 321 (7), 255 ([M - SiMe2(C10H19)]þ, 24), 241 (15), 181 (34), 155 (24), 141 (36), 116 (65), 97 (29), 73 ([TMS]þ, 90), 59 (100). (E)-1-Pentamethyldisilanylmethylene-2-cyclohexene, 9. Colorless oil. 1H NMR (CDCl3, 300 MHz): δ 0.06 (s, 9H, SiMe3), 0.15 (s, 6H, SiMe2), 1.71 (apparent quint, 3JHCCH = 6.2 Hz, 2H, H-6), 2.08-2.14 (m, 2H, H-5), 2.36 (m, 2H, H-7), 5.27 (br s, 1H, H-1), 5.79 (dt, 3JHCCH =4.5 Hz, 3JHCCH = 9.8 Hz, 1H, H-4), 6.09 (apparent dt, 3JHCCH=9.8 Hz, 4JHCCCH=1.8 Hz, 1H, H-3). 13 C{1H} NMR (CDCl3, 75 MHz): δ -2.7 (SiMe3), -1.9 (SiMe2), 23.0 (C-6), 25.2 (C-5), 30.9 (C-7), 124.9 (C-1), 129.6 (C-4), 132.9 (C-3), 151.6 (C-2). 29Si NMR (CDCl3, 60 MHz): δ -18.4, -29.3. IR (neat, cm-1): 2948, 2895, 1712, 1684, 1576, 1429, 1394, 1246, 1065, 837, 808, 791, 690. GC-MS m/z (% relative intensity): 224 ([M]þ, 54), 209 ([M - Me]þ, 18), 165 (18), 135 (100), 131 ([SiMe2SiMe3]þ, 24), 123 (43), 109 (18), 95 (20), 91 (20), 85 (27), 78 (10), 73 (99), 59 (91). HRMS (EI): calcd for C12H24Si2 m/z 224.1417, found 224.1423. A NOE experiment was performed by irradiation of a signal at 5.27 ppm (Scheme 9). Hydrosilylation Polymerization of 1,7-Octadiyne with 1,3Dihydrohexamethyltrisilane. To AlCl3 (1.00 mmol) and dichloromethane (1.0 mL) placed in a Schlenk tube kept at 0 °C was added 1,3-dihydrohexamethyltrisilane (1f) (1.00 mmol), and the mixture was stirred for 7 min at that temperature. 1,7-Octadiyne (2J) (1.00 mmol) was added to the mixture. The resulting mixture was stirred for 65 h at that temperature and quenched with triethylamine (0.2 mL) and saturated aqueous NaHCO3 (1.0 mL). The organic phase was analyzed by GC after addition of biphenyl as internal standard. After GC and GC-MS analyses, the mixture was separated, the aqueous phase was extracted with dichloromethane (1 mL 4 times), and the combined organic phase was washed with brine (5 mL) and dried over sodium sulfate. The filtrate of the dried solution was evaporated to leave 0.26 g of a residue, which was analyzed by NMR spectroscopy. Then the residue was dissolved in dichloromethane (5 mL) and the solution was poured into methanol (100 mL) to develop a suspension, which was separated by decantation to give 0.08 g of a solid material (poly-10fJ) and also 0.2 g of liquid material after evaporation of the liquid phase. Poly-10fJ. 1H NMR (CDCl3, 300 MHz) obtained for the solid material (intensities given are observed values, relative to 12H assignable to SiMe2SiMe2SiMe2 at 0.19 ppm): δ ∼0.10 (s, 5.0H, SiMe2SiMe2SiMe2), ∼0.19 (s, 12H, SiMe2SiMe2SiMe2), 1.26-1.38 (br m, 7.2H, CH2CH2CH2CH2, perhaps overlapping with other unknown signals), 2.07 (apparent br d, 3.9H CH2CH2CH2CH2), 5.47 (d, 1.7H, 2SiMe2CH), 6.32 (dt, 1.6H, 2SiCHdCH). Besides these signals, the spectrum displayed unidentified signals at 0.88 and 2.2-2.7 ppm. 1-[(Z)-(1-Decen-1-yl)]-1,1,2,3,3-pentamethyltrisilane, 11-I. This compound was isolated by preparative HPLC. Colorless oil. 1H NMR (CDCl3, 300 MHz): δ 0.15 (d, 3H, 3JHCSiH = 5.1 Hz, SiSiMeSi), 0.18 (dd, 3H, 3JHCSiH = 4.5 Hz, 4JHCSiSiH = 1.5 Hz, SiSiSiHMe), 0.19 (d, 3H, J = 0.7 Hz, SiSiSiHMe), 0.21 (d, 3H, 4 JHCSiSiH = 0.5 Hz, SiHSiHSiMe), 0.25 (s, 3H, SiHSiHSiMe), 0.88 (t, 3H, 3JHCCH =6.6 Hz, CH3CH2), 1.18-1.43 (br, 12H, 6CH2), 2.11 (dt, 2H, 3JHCCH = 7.0 Hz, 3JHCCH = 7.1 Hz, CdC-CH2), 3.17-3.22 (m, 1H, SiSiHSi), 3.80-3.86 (d-sept, 1H, 3JHSiCH = 4.5 Hz, 3JHSiSiH = 1.5 Hz, SiSiSiH), 5.50 (dt, 1H, 3JHCCH = 12.9 Hz, 4 JHCCCH = 1.4 Hz, SiCHdC), 6.33 (dt, 1H, 3JHCCH = 12.9 Hz, 3 JHCCH = 7.1 Hz, C=CHC). IR (neat, cm-1): 2958, 2927, 2856, 2131, 1716, 1606, 1466, 1410, 1379, 1257, 1057, 908, 879, 837, 798, 771. GC-MS m/z (% relative intensity): 300 ([M]þ, 15), 255 (16), 241 ([M - SiHMe2]þ, 14), 197 (30), 181 (23), 160 (16), 155 (18), 141 3
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Organometallics, Vol. 29, No. 21, 2010
(40), 127 (30), 116 (70), 102 (89), 97 (37), 83 (14), 73 (79), 59 (100). HRMS (EI): calcd for C15H36Si3 m/z 300.2125, found 300.2122. 1,2-Di[(Z)-(1-decen-1-yl)]-1,1,2,3,3-pentamethyltrisilane, 11II-a, and 1,3-Di[(Z)-(1-decen-1-yl)]-1,1,2,3,3-pentamethyltrisilane, 11-II-b. Since separation of an approximately 1:1 mixture of 11-II-a and 11-II-b, isolated by preparative HPLC, was not possible, NMR and HRMS analyses were made for the mixture. Colorless oil. 1H NMR (CDCl3, 300 MHz): δ 0.12-0.25 (m, 15H, 5SiMe), 0.88 (t, 6H, 3JHCCH = 6.6 Hz, 2CH3CH2), 1.20-1.41 (br, 24H, 12CH2), 2.02-2.15 (m, 4H, 2CdC-CH2), 3.20 (quart, 0.5H, 3JHSiCH = 5.2 Hz, 0.5SiSiHSi in 11-II-b), 3.82 (sept, 0.5H, 3JHSiCH = 4.5 Hz, 0.5SiSiSiH, 11-II-a), 5.43-5.51 (m, 2H, 2SiCHdC), 6.23-6.34 (m, 2H, 2CdCHC). IR (neat, cm-1): 2956, 2925, 2854, 2087, 1603, 1466, 1408, 1377, 1244, 874, 837, 777, 688. HRMS (EI): calcd for C25H54Si3 438.3533, found 438.3539. 1,2,3-Tri[(Z)-(1-decen-1-yl)]-1,1,2,3,3-pentamethyltrisilane, 11-III. This compound was isolated by preparative HPLC. Colorless oil. 1H NMR (CDCl3, 300 MHz): δ 0.22 (s, 6H, 2SiSiSiMe), 0.23 (s, 6H, 2SiSiSiMe), 0.26 (s, 3H, SiSiMeSi), 0.88 (t, 9H, 3JHCCH=6.6 Hz, CH3CH2), 1.17-1.42 (br, 36H, 18CH2), 2.00-2.12 (m, 6H, 3CdC-CH2), 5.45 (dt, 1H, 3JHCCH=13.6 Hz, 4 JHCCCH = 1.2 Hz, SiCHdC), 5.75 (dt, 2H, 3JHCCH = 13.6 Hz, 4 JHCCCH =1.2 Hz, 2SiCHdC), 6.30 (dt, 3H, 3JHCCH =13.6 Hz, 3 JHCCH =7.6 Hz, 3CdCHC). 13C{1H} NMR (CDCl3, 75 MHz): δ -6.1 (SiSiMeSi), -0.9 (SiSiSiMe 2), 14.1, 22.7, 29,3, 29.57, 29.59, 29.63, 29.93, 31.9, 34.1, 34.7, 124.2, 127.8, 149.0, 149.1. 29Si NMR (CDCl3, 60 MHz): δ -25.0, -54.6. IR (neat, cm-1): 2956, 2927, 2854, 1603, 1466, 1244, 1045, 837, 819, 773, 687. GC-MS m/z (% relative intensity): 463 ([M - C8H17]þ, 43), 379 (19), 321 (10), 311 (11), 267 (13), 253 (19), 241 (17), 225 (10), 197 (20), 181 (27), 169 (13), 155 (32), 141 (46), 131 (14), 127 (26), 117 (33), 111 (27), 103 (12), 97 (39), 85 (24), 73 (50), 59 (100). HRMS (EI): calcd for C35H72Si3 576.4942, found 576.4948.
Kato et al. Reaction of Poly(phenylsilylene) with 1-Decyne. The reaction of poly(phenylsilylene) (1i) (Mw =2697, Mw/Mn =1.63 as analyzed by GPC with polystyrene standards) with 1-decyne (2C) (1 equiv relative to a SiHPh repeat unit in the polymer) was run at 0 °C in CH2Cl2 using AlCl3 (10 mol % relative to 1-decyne) for 26 h. Quenching with triethylamine and aqueous sodium bicarbonate, extraction with CH2Cl2, drying over sodium sulfate, filtration through a Florisil column, and evaporation of the filtrate gave product polymer 12 (190 mg) as a pale yellow oil. The oily material was fractionated by preparative HPLC to isolate higher molecular weight fraction 120 as a sticky oil (84 mg). Molecular weight and extent of introduction of decenyl units were analyzed by GPC and 1H NMR spectroscopy. Higher Molecular Weight Fraction 120 of the Polymer Obtained from the Reaction of Poly(phenylsilylene) with 1-Decyne. Pale yellow sticky oil. 1H NMR (CD2Cl2, 300 MHz): δ 0.2-2.9 (br, alkyl-H), 3.7-4.5 (br, SiH), 4.5-6.0 (br, alkenyl-H), 6.0-8.1 (br, Ph). IR (neat, cm1): 3066, 3049, 2954, 2929, 2918, 2852, 2104, 1593, 1483, 1466, 1427, 1377, 1134, 1101, 1066, 1028, 997, 735, 698.
Acknowledgment. This work was supported by a Grant-in-Aid for Scientific Research (No. 21605005) from the Ministry of Education, Culture, Sports, Science and Technology, Japan. Supporting Information Available: Experimental details, spectral and/or analytical data of minor products (E)-3aA, (E)-3aC, r-3aC, r-3aE, (E)-3aF, 3aF-saturated, 5, 6, (Z)-3aD0 , (Z,r)-8eC, 1bG, 1bG-(SiMe2)2H, 11-II-a, and 11-II-b, NMR spectra of products, and crystallographic data for 40 in CIF format. This material is available free of charge via the Internet at http://pubs.acs.org.