Organometallics 1995,14,1204-1212
1204
Silicon-Carbon Unsaturated Compounds. 52. Thermal Reaction of 1-Mesityl-,1-0-Tolyl-,and 1-p-Tolyl-3-phenyl1,2=bis( trimethylsilyl)silacycloprop-2-enes Atsutaka Kunai," Yoichi Matsuo, Joji Ohshita, Mitsuo Ishikawa," Yoshio Aso, Tetsuo Otsubo, and Fumio Ogura Department of Applied Chemistry, Faculty of Engineering, Hiroshima University, Kagamiyama, Higashi-Hiroshima 724,Japan Received August 8, 1994@ Thermal reaction of 1-mesityl-, 1-o-tolyl-, and 1-p-tolyl- 3-phenyl-l,2-bis(trimethylsilyl)silacycloprop-2-enes ( l a - l c ) has been studied. The thermolysis of l b afforded 3,3-dimethyl4-phenyl-l-o-tolyl-5-(trimethylsilyl)-l,3-disilacyclopent-4-ene (2b), l-o-tolyl-1,3-bis(trimethylsily1)-1-silaindene(3b), and l-o-tolyl-2,3-bis(trimethylsilyl)-l-silaindene (4b), while the thermolysis of ICproduced 3,3-dimethyl-4-phenyl-l-p-tolyl-5-(trimethylsilyl)-l,3-disilacyclopent-kene (2c), l-p-tolyl-l,3-bis(trimethylsily1)-l-silaindene (3c),and l-p-tolyl-2,3-bis(trimethylsily1)-1-silaindene(4c). The thermolysis of l b in the presence of phenyl(trimethylsily1)acetylene afforded (Z)-3-phenyl-l-[2-phenyl-1,2-bis(trimethylsilyl~ethenylll-o-tolyl-2-(trimethylsilyl)silacycloprop-2-ene (7b),together with 2b, 3b, and 4b, while the similar reaction of ICproduced (2)-and (E)- l-[2-phenyl-1,2-bis(trimethylsilyl)ethenyll-lo-tolyl-2-(trimethylsilyl)-l-silaindene, in addition to 2c, 3c, and 4c. The reactions of l b and IC in the presence of methyldiphenylsilane produced Z and E isomers of 1-(2-methyl-2,2diphenyl-1-o-tolyldisilany1)-and l-(2-methyl-2,2-diphenyl-l-p-tolyldisilanyl)2-phenyl-1,2bis(trimethylsilyl)ethene, respectively. The structure of l-mesityl-5-phenyl-4,6,7-tris(trimethylsily1)-1-silabenzo[blnorbornadiene(6a),which is produced from the reaction of l a with phenyl(trimethylsilyl)acetylene,was reinvestigated. 6a crystallizes in the space group P21/a with cell dimensions of a = 23.955(7) A, b = 12.664(1) A, c = 11.514(1) A, a = y = go", ,9 = 98.76(2)", V = 3452(1) Hi3, Z = 4, and Dcalcd = 1.095 g/cm3. 7b crystallizes in the space group P21/c with cell dimensions of a = 18.880(1) A, b = 9.4251(7) A, c = 20.938(3) A, a = y = 90.0", ,9 = 115.069(6)", V = 3374.9(3) A3, Z = 4, and Dcalcd= 1.065 g/cm3. Scheme 1
Introduction Silacyclopropenes, which can readily be prepared by the photolysis of phenylethynylpolysilanes,l undergo a wide variety of reactions, depending on the substituents on the silicon atom and the reaction condition^.^-^ For example, the reaction of l-mesityl-3-phenyl-l,2-bis(trimethylsilyl)silacycloprop-2-ene (la)with a Ni(PPh3)l catalyst produces a nickelasilacyclobutenewhich isomerizes to a silapropadiene-nickel complex. The silapropadiene-nickel complex undergoes further rearrangement to give two isomers of a benzodisilacyclohexene derivative as the final products, via C-H bond activation of a methyl group on the mesityl ring (Scheme l).63' Abstract published in Advance ACS Abstracts, February 1, 1995. (1)(a) Ishikawa, M.; Fuchikami, T.; Kumada, M. J . Am. Chem. SOC. 1977,99,245. (bj Sakurai, H.; Kamiyama, Y.; Nakadaira, Y. J . Am. Chem. SOC.1977,99,3879. (2) Ishikawa, M.; Kovar, D.; Fuchikami, T.; Nishimura, K; Kumada, M.; Higuchi, T.; Miyamoto, S. J. Am. Chem. SOC.1981,103, 2324. (3) Ishikawa, M.; Nishimura, K.; Ochiai, H.; Kumada, M. J . Organomet. Chem. 1982,236,7. (4) Ishikawa, M.; Sugisawa, H.; Fuchikami, T.; Kumada, M.; Yamabe, T.; Kawakami, H.; Ueki, Y.; Shizuka, H. J.Am. Chem. SOC.1982, 104,2872. ( 5 ) Ishikawa, M.; Matsuzawa, S.; Sugisawa, H.; Yano, F.; Kamitori, S.: Hieuchi, T. J . Am. Chem. SOC.1985.107.7706. '(6)ishikawa, M.; Ohshita, J.; Ito, Y.;Iyoda, J. J . Am. Chem. SOC. 1986,108,7417. (7) Ohshita, J.; Isomura, Y.; Ishikawa, M. Organometallics 1989, 8,2050. (8)Ishikawa, M.; Yuzuriha, Y.; Horio, T.; Kunai, A. J . Organomet. Chem. 1991,402,C20. (9) Ishikawa, M.; Horio, T.;Yuzuriha, y.; Kunai, A,; Tsukhara, T.; Naitou, H.Organometallics 1992,11, 597.
,SiMe3
Ph,
c=c A \ / Me:
Si 'SiMe3
la
2a PhC.CSiMel
Ph
@
Me$
Mes 5a
Mes
SiMe3
6a
Sa'
More recently, we have reported that the thermolysis of la in the absence of a trapping agent produces l-mesityl-3,3-dimethyl-4-phenyl-5-(trimethylsilyl)-1,3disilacyclopent-4-ene @a) and l-mesityl-1,3-bis(trimethylsily1)-1-silaindene(3a),8while in the presence of
0276-733319512314-1204$09.0010 0 1995 American Chemical Society
Organometallics, Vol. 14,No. 3, 1995 1205
Silicon-Carbon Unsaturated Compounds
Scheme 2
Table 1. Thermal Reaction of Silacycloprop-2-enesla-lc in the Presence or Absence of Trapping Agent compd additivea
la R'= Mes, R2=SiMe, lb R'= o-Tol, R2=SiMe, le R'=p-Tol, R2=SiMe,
lab lb lb lb lb lbc IC IC IC IC IC lcc lab lb lb lb IC IC lb lb lb IC IC IC
none none none none none none none none none none none none PTA
temp, time, "C h 280 280 250 150 130 100 280 250 200 150 130 100 280 280 230 200 280 250 280 250 230 280 250 200
6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6
product (yield, 70) 2a(49) 2b(6) 2b(5) 2b(7) 2b(7) 2b(7) 2c(5) 2c(6) 2c(3) 2c(5) 2c(ll) 2c(O) 2a(13) 2b(6) 2b(11) 2b(4) 2c(5) 2c(5) 2b(6) 2b(9) 2b(3) 2c(2) 2c(2) 2c(2)
3a(28) 3b(3) 3b(5) 3b(8) 3b(58) 3b(21) 3c(10) 3c(9) 3c(4) 3c(20) 3c(36) 3c(O) 3a(23) 3b(12) 3b(4) 3b(4) 3c(8) 3c(2) 3b(7) 3b(6) 3b(7) 3c(8) 3c(3) 3c(3)
4b(4) 4b(8) 4b(4) 4b(S) 4b(10) 4c(10) &(6) 4c(4) 4c(14) 4c(9) 4c(O) Sa(20) 4b(20) 4b(17) 4b(1) 4c(8) 4c(11) 4b(11) 4b (13) 4b(13) 4c(4) 4c(4) 4c(2)
phenyl(trimethylsilyl)acetylene, l a affords two adducts, along with 2a and 3a (Scheme 119 The structure of one of two adducts was confirmed to be c-7a-mesityl-2phenyl-1 ,r-2a,c-7-tris(trimethylsilyl)cyclobutenosila6a(26) indan (Sa)by an X-ray crystallographic study.1° Since PTA 7b(17) all spectral data for the other product were quite similar PTA 7b(44) to those of 5a, we concluded this compound as a regio PTA 7b(44) PTA Sc(13) 9c(10) isomer of Sa, ~-7a-mesityl-l-pheny1-2,r-2a,t-7-tris(triPTA Sc(75) 9c(11) methylsily1)cyclobutenosilaindan (5a'). NOE-FID difMDS lOb(4) l l b ( 1 ) ference experiments at 270 MHz also suggested the MDS lOb(14) llb(10) structure proposed for 5a'. However, during the course MDS lOb(1) l l b ( 1 ) MDS lOc(4) llc(2) of further study on the reaction of silacyclopropenes,we MDS lOc(60) llc(18) suspected that erroneous structural assignment had MDS lOc(0) llc(0) been made for 5a' and found that this compound must PTA and MDS stand for phenyl(trimethylsily1)acetylene and methylbe l-mesityl-5-phenyl-4,6,7-tris(trimethylsilyl)-l-siladiphenylsilane, respectively. Results of previous work? Conversion of benzo[b]norbornadiene (6a). We also found that the starting material was very low. thermal behavior of related compounds, 1-0-tolyl-and l-p-tolyl-3-phenyl-l,2-bis(trimethylsilyl)silacycloprop-2Scheme 3 enes ( l b and IC)in the presence of phenyl(trimethy1Ph. SiMe3 sily1)acetyleneis quite different from that of la. In this C=C' \ / la R=MH paper, we report the thermal reaction of la-lc in the Si l b RW-TOl presence or absence of trapping agents and the results M ~ ~ s'R ~ ' IC RY-ToI of an X-ray diffraction study for 6a.
Results and Discussion Silacyclopropene l a used as the starting compound was prepared by irradiating 2-mesity1-24phenylethynyllhexamethyltrisilane with a low-pressure mercury lamp in hexane, followed by distillation as reported R previously (Scheme 2h7 Similarly, lb and IC were prepared by the photolysis of 2-0-tolyl- and 2-p-tolyl-2(phenylethyny1)hexamethyltrisilanes in 41-46% and 25-36% yields, respectively.ll As reported previou~ly,~,~ the thermolysis of l a at 280 "C for 6 h produces isomerization products 2a and 3a in 49% and 28% yields, respectively. The thermolysis of l b and IC also produced isomerization products analogous to 2a and 3a (Table 1).12 Thus, when l b was heated in a degassed sealed tube at 130 "C for 6 h, 3,3dimethyl-4-phenyl-l-oo-tolyl-5-( trimethylsilyl)-1,3-disilacyclopent-4-ene(2b)and l-o-tolyl-l,3-bis(trimethylsilyl)1-silaindene (3b)were obtained in 7% and 58% yields, together with a 5% yield of l-o-tolyl-2,3-bis(trimethylsily1)-1-silaindene(4b)(Scheme 3). Similar thermolysis 2a R=Me 3a R=Mes of ICunder the same conditions produced 3,3-dimethyl2b RW-To1 4b RW-To1 3b RW-To1 4c R=p-To1 3c R T T o l 2c R=p-To1 4-phenyl-1-p-tolyl -5-(trimethylsilyl)-1,3-disilacyclopent4-ene (2c),l-p-tolyl-l,3-bis(trimethylsilyl)-l-silaindene (3c), and l-p-tolyl-2,3-bis(trimethylsilyl)-l-silaindene thermolysis of l b and IC a t temperatures higher than 150 "C resulted in the decrease of the yields of main (4c) in 11%,36%, and 9% yields, respectively. The products 3b and 3c. At 100 "C, however, the rate of (10)The positions of the trimethylsilyl and phenyl groups in 5a were isomerization of l b and IC was extremely slow, and inversely shown in Scheme I1 of the previous paper (ref 9). The correct most of the starting compound was recovered after 6-h form for 5a is exhibited in the stereoview (Figure 1) of the same paper. reaction. See also erratum shown in Organometallics 1992,11, No. 10, p 3486. (11)l b and IC are thermally stable at room temperature but The structures of these products were verified by sensitive to oxygen and moisture in air. spectrometric analysis, as well as by elemental analysis. (12) In contrast to silacyclopropanes, silacyclopropenes do not Like 2a,8the lH NMR spectrum of disilacyclopentene eliminate silylenes thermally, but undergo thermal isomerization.
?-I
Kunai et al.
1206 Organometallics, Vol. 14, No. 3, 1995 7.70 (d)
Hm
7.35 (t)
7.56 (d)
r
0.46 (s)
SiMe3
7.20 (t)H
+
6
Si
SiMe3 0.19 (s)
H 7.15 (d)
4b
absence of the acetylene, but no change is observed in the yield of 3a. These results indicate that silacycloprop-1-ene A was trapped by the acetylene (Scheme 4).13J4 Therefore, the formation Of 5a may be explained by [2 21 cycloadditionof A with phenyl(trimethylsily1)acetylene giving intermediate (E) (path a), followed by isomerization of E to another intermediate (F).A 1,3hydrogen shiR in intermediate F to restore the aromatic sextet would produce 5a as proposed p r e v i o ~ s l y . An ~~J~ alternative pathway involving scission of a C-C bond in the silacycloprop-1-enyl ring of A (path b), leading to intermediate (GIand silene (HI, and then [2 21 cycloaddition of silene H with the acetylene would produce 5a. However, examination of stereo models indicates that [2 21 cycloaddition of silene H with the acetylene seems to be unfavorable because of a large steric hindrance. In contrast to the formation of 5a, adduct 6a can be understood in terms of a series of the reaction involving scission of an Si-C bond of the silacycloprop-1-enylring of A (path c).16As shown in Scheme 4, a 1,3-hydrogen shift in intermediate (J)derived from ring enlargement of A would produce another silene intermediate (K). The [4 21 cycloaddition of this intermediate with the acetylene would produce 6a. In this reaction, intermemight be formed from intermediate J via a 1,3diate (L) hydrogen shift.17 However, no products arising from silene L were detected in the reaction mixture. Presumably, [2 21 cycloaddition of this silene with the acetylene is sterically unfavorable, as in the case of the reaction of silene H. We also carried out the thermolysis of l b and ICin the presence of phenyl(trimethylsily1)acetylene. Interestingly, the thermolysis of l b in the presence of the acetylene afforded a product quite different from those of la. Thus, heating l b in the presence of phenyl(trimethylsily1)acetylene at 230 "C for 6 h produced (2)3-phenyl-142-phenyl-172-bis( trimethylsily1)ethenyll-l-otolyl-2-(trimethylsilyl)silacycloprop-2-enes (7b)in 44% yield, together with 2b (ll%), 3b (4%),and 4b (17%), while at 280 "C for 6 h, the similar reaction of l b gave 7b only in low yield. Product 7b is thermally and oxidatively stable. For example, when 7b was heated in a degassed sealed tube at 200 "C for several hours, 7b was recovered quantitatively. 7b can be recrystallized from ethanol without decomposition even under aerobic conditions.
Me 2.35 (s)
4c
Figure 1. lH NMR chemical shifts of silaindenes 4b and 4c.
2b reveals two singlet resonances due to nonequivalent dimethylsilyl protons at 6 -0.08 and 0.22 ppm and resonances due t o an ABX spin system of the ring CH2SiH unit a t 6 -0.05 (dd), 0.23 (dd), and 5.19 (dd) ppm. The 'H NMR spectrum of 2c also shows similar signals at 6 0.13, 0.20 (MeSi), -0.11 (dd), 0.19 (dd), and 5.11 (dd) ppm (CH2SiH). As observed for 3a,8the 'H NMR spectrum of silaindene 3c reveals resonances characteristic to the silaindene ring at 6 6.93 (s, C2-H), 7.20 (t, C6-H), 7.34 (t, C5-H), 7.52 (d, C4-H), and 7.65 (d, C7-H)ppm, together with resonances due top-tolyl ring protons a t 6 7.13 (d, 2H, m-H) and 7.42 (d, 2H, o-H) ppm. A similar pattern is also observed in the lH NMR spectrum of 3b. In contrast to 3b and 3c, a proton signal due to SiH appears a t 6 5.15 ppm for 4b and 6 5.14 ppm for 4c, but the signal characteristic to C2-H is not observed for these compounds. The lH NMR chemical shifts for silaindenes 4b and 4c are shown in Figure 1. The location of protons on the silaindenyl ring as well as protons in the tolyl ring for 3b,c and 4b,c was confirmed by lH-'H COSY experiments at 270 MHz. These results are wholly consistent with the structures proposed for these products. The formation of products 2a-c, 3b,c, and 4a-c can best be understood by a series of reactions shown in Scheme 3.8,9 A 1,2-trimethylsilyl shift from the silicon atom to the sp2 carbon at the C3 position in the silacyclopropenyl ring would produce silacycloprop-lene intermediate (A), which isomerizes to give silylene species (C and C') as the reactive intermediates. The silylenes thus formed insert intramolecularly into a C-H bond of either the trimethylsilyl group or phenyl group, which is located on the same side as the silylene center with respect to a carbon-carbon double bond to give 2a-c or 4a-c, respectively. The products 3a-c may be explained by isomerization of the silacyclopropenes la-c to a silapropadiene (B),followed by a hydrogen shift from the ortho position of the phenyl ring to the internal carbon of the silapropadiene and then coupling of the resulting diradical (D) to form a silaindene ring. Previously, we reported that the thermolysis of l a in the presence of a large excess of phenyl(trimethylsily1)acetylene a t 280 "C for 6 h gives two adducts 5a and 5a' in 20% and 26% yields, along with 2a (13%)and 3a (23%19 The structure of 5a' was reexamined by an X-ray diffraction study and verified to be l-mesityl-5phenyl-4,6,7-tris(trimethylsily1)-l-silabenzo[blnorbornadiene (6a) (see below). In the thermolysis of l a in the presence of phenyl(trimethylsilyl)acetylene, the yield of 2a decreases markedly, compared with that of the reaction in the
+
+
+
+
(13)Barton and his co-workersl4a,b have reported that, in the thermal rearrangement of methylvinyllsilylene to ethynylmethylsilane, the intermediacy of 1-methylsilacycloprop-1-eneseems to be thermodynamically unfavorable on the basis of ab initio calculations for structural isomers with the formula CZSiI& reported by Gordon et al.,'" and the reaction may proceed via l-methyisilacycloprop-2-ene, which is in equilibrium with the starting vinylsilylene. However, in the case of silacyclopropenes having bulky substituents on the ring, especially in the case of la, the formation of 5a and 6a can best be rationalized in terms of intermediate A. (14)(a) Barton, T. J.; Burns,G. T.; Coure, W. F.; Wulff, W. D. J. Am. Chem. SOC.1982,104,1149. (b) Barton, T. J.; Burns, S. A,; Burns, G. T. Organometallics 1983,2, 199. (c) Gordon. M. S.; Koob, R. D. J. Am. Chem. SOC.1981,103, 2939. (15)The addition of phenyl(trimethylsily1)acetylene to intermediate A may occur from the side of the phenyl group, although alternative geometry for intermediate E has been shown in ref 9. (16) It seems likely that S a and 6a may be formed by different pathways, because no interconversion between 5a and 6 a is observed under the conditions used. (17) Thermal and photochemical 1,3-hydrogen shifts in a sillacyclopentadienyl ring system has been reported: Khabashesku, V. N.; Balaji, V.; Boganov, S. E.; Nefedov, 0. M.; Michl, J. J.Am. Chem. SOC. 1994, 116, 320.
Organometallics, Vol. 14, No. 3, 1995 1207
Silicon-Carbon Unsaturated Compounds Scheme 4 SiMe,
H I
_I
Mes
~~
I
W
SiMe3
Mes A
SiMe,
H SiMe3
Mes
4
K F'hCkCSiMe,
no cycloadduct
no cycloadduct
Mes 6a
SiMe3 Me3Si
On the other hand, when the reaction of IC with phenyl(trimethylsily1)acetylene was carried out at 250 "C for 6 h, no silacyclopropene analogous to 7b was and (E)detected in the reaction mixture. Instead, (2)1-12-phenyl-1,2-bis(trimethylsilyl)ethenyl]-l-o-tolyl-2(trimethylsily1)-l-silaindenes(8c and 9c)were obtained in 75% and 11%yields, as main products. The structures of 8c and 9c were verified by spectrometric analysis, and the location of substituents was confirmed by NOE-FID difference experiments at 270 MHz. For 9c, saturation of trimethylsilyl protons (6 -0.05) at the C2 position caused a positive NOE of a proton (s,6 7.80) at the C3 position, as well as o-protons (d, 2H, 6 7.43) in the p-tolyl ring, while saturation of trimethylsilyl protons (6 -0.08) at the p position of the olefinic unit resulted in enhancement of trimethylsilyl protons (6 0.28) at the a position, o-protons in thep-tolyl ring, and o-protons (d, 6 6.71) in the phenyl ring. Irradiation of trimethylsilyl protons at the a position caused enhancement of a proton (d, 6 7.62) a t the C7 position and the trimethylsilyl protons at the p position. In the similar NOE-FID difference experiments for geometric isomer 812, saturation of trimethylsilyl protons at the a position (6 0.44) with respect to the olefinic unit caused enhancement of a proton (6 7.61) at the C7 position and trimethylsilyl protons (6 0.38) at the C2 position, but no enhancement was observed for trimethylsilyl protons at the p position (6 -0.29), indicating that these trimethylsilyl groups are located in a trans fashion. Irradiation of trimethylsilyl protons at the C2 position resulted in enhancement of a proton at the C3 position (s, 6 8.051, as well as o-protons (d, 2H, 6 7.55) in the p-tolyl ring and trimethylsilyl protons at the a and p positions. These results unambiguously support the structures proposed for 8c and 9c. In order to obtain more information for the reactive species leading to these products, we carried out the reaction of lb and IC in the presence of a hydrosilane. Thus, heating lb at 250 "C for 6 h in the presence of methyldiphenylsilane afforded (2)-1-(2-methyl-2,2-diphenyl- l-o-tolyldisilanyl)-2-phenyl1,2-bis(trimethyl-
F
5a
si1yl)ethene (lob) and (E)-1-(2-methyl-2,2-diphenyl-lo-tolyldisilanyl)-2-phenyl-l,2-bis(trimethylsilyl)ethene (llb)in 14% and 10% yields, along with 3b (9%),4b (6%), and 5b (13%), while the similar reaction of IC produced (2)1-(2-methyl-2,2-diphenyll-p-tolyldisilany1)2-phenyl-1,2-bis(trimethylsily1)ethene ( 1Oc) and (E)-1(2-methyl-2,2-diphenyl-l-p-tolyldisilanyl)-2-phenyl-l,2bis(trimethylsily1)ethene (llc)in 60% and 18%yields, respectively, together with 3c (2%), 4c (3%),and 5c (4%). The production of these compounds clearly indicates that silylene species C and C' play an important role in the thermal reactions for lb and IC (see Scheme 3). The structures of lob, lOc, llb,and llc were verified by spectrometric analysis, and their 2 and E geometries were established by NOE-FID difference experiments at 270 MHz. For llc, irradiation of trimethylsilyl protons at the position p (6 -0.24) to the disilanyl group caused a strong enhancement of trimethylsilyl protons at the a position (6 0.301, while saturation of the trimethylsilyl protons at 6 0.30 ppm resulted in enhancement of the trimethylsilyl protons at 6 -0.24 ppm as well as a proton at 6 5.33 ppm (SiH), indicating that llc must have the E configuration. For lOc,however, irradiation of trimethylsilyl protons at the a (6 -0.05) and ,8 (6 -0.45) positions, respectively, caused no effect for the trimethylsilyl protons, as expected for the 2 configuration. For 10b and llb, all attempts to separate these two isomers using recycling HPLC were unsuccessful. The isolated samples were always contaminated with a small amount of the other isomer. Nevertheless, their E and 2 configurations could be readily confirmed by NOE-FID difference experiments in a manner similar to the above. Scheme 5 illustrates a possible mechanistic interpretation for the formation of 7b, lob, lOc, llb, and llc in the reaction of lb and IC. The silylene species C and C' derived from A insert into an Si-H bond of the hydrosilane to afford 10b,c and llb,c,respectively. The formation of 7b can be understood by cycloaddition of
1208 Organometallics, Vol. 14,No. 3, 1995
Kunai et al. Table 2. Crystal Data, Experimental Conditions, and Summary of Structural Refinement for 6a and 7b
Scheme 6
L
L
Ph2MeSiH
PhzMcSiH
compound mol formula mol wt space group cell dimens a, A b, A c,
A
a, deg P9
deg
Y.deg
v,A3
Z lob R=o-To1 10c R=p-To1
l l b R=o-To1 l l c R=p-Tol
7b R=o-Tol
Scheme 6 C'
C
I
Ph,
c,=,c .
1
F'hCSSiMe3
F'hCECSiMe,
,SiMe,
Ph,
C,=f
..
I
y
Si p-Tol' Me3Si
SiMe3
Ph
x
Si
p-Tol'
SiMe,
Ph
SiMe,
SiMe3
, Mdm3 cryst size, mm cryst color p, mm-' diffractometer temp, K wavelength, A monochrometer scan type scan speed, deglmin scan width, deg diffraction geometry range of h, k, 1 h &dcd
k 1 no. of unique reflns no. of obsd reflns (IFol z 3u(F0)) RSP F(0W R RW"
6a
7b
c3fi8sb
c32hs4
569.10 P 21la
P 2llC
541.04
23.955(7) 12.664(1) 11.514(1) 90.0 98.76(2) 90.0 3452(1) 4 1.095 0.9 x 0.8 x 0.8 colorless 1.62 RigakU AFC-6C 298 1.5418 (CuKa) graphite crystal w - 2% 6 o 5 28 5 126 symmetrical A
18.880(1) 9.4251(7) 20.938(3) 90.0 115.069(6) 90.0 3374.9(3) 4 1.065 0.5 x 0.3 x 0.3 colorless 1.63 Rigaku AFC-6C 298 1.5418 (Cu Ka) graphite crystal w - 2%
-28 5 h 5 28 Osk515 051513 5258 4953 0.013 1232 0.096 0.142
-24 5 h 5 24 0 5 k s 10 051521 5177 3788 0.043 992 0.085 0.079
4
o 5 28 5 126 symmetrical A
+
Weighting scheme is ( U ( F , ) ~ 0.0004~Fo12)-1
I
1 a i i M e 3 p-Tol' Me3& SiMe,
)=("
9c
silylene C generated from lb to the triple bond of phenyl(trimethylsily1)acetylene. As shown in Scheme 6, products 8c and 9c may be explained by isomerization of silacyclopropenes(7c and 7c') which would be produced by the cycloaddition of C and C' derived from IC to the acetylene. Homolytic scission of a silicon-carbon bond in the silacyclopropene ring of 7c and 7c', followed by a 1,3-hydrogenshift from the ortho position of the phenyl ring to the a position of the carbon-carbon double bond would produce diradical intermediates. The coupling reaction of the resulting diradicals produces 8c and 9c, respectively. X-ray Analysis of 6a and 7b. The colorless crystals of 6a and 7b were obtained by recrystallization from ethanol, and their structures were solved by an X-ray crystallographic analysis. The experimental conditions and summary of structural refinement for 6a and 7b are listed in Table 2. For 6a, the final atomic coordinates and equivalent isotropic temperature factors are given in Table 3. The ORTEP view of the molecular structure with the atomic
numbering scheme is shown in Figure 2, and selected bond distances and angles are listed in Table 4. The thermal parameters of the methyl carbon atoms attached t o Si4 are large, suggesting an orientational disorder by rotation about the C5-Si4 bond. For 7b, the final atomic coordinates and equivalent isotropic temperature factors are given in Table 5. The ORTEP view and the atomic numbering scheme of the molecule are shown in Figure 3, and selected bond distances and angles are listed in Table 6. The data reveal some lengthening of the bond between Si3 and C7 (1.981(6) A), indicating the existence of a large steric repulsion caused by trimethylsilyl, phenyl, and silacyclopropenyl substituents. For 6a and 7b, there are no close intermolecular contacts.
Experimental Section General Procedures. All thermal reactions were carried out in a 10 cm x 0.8 cm degassed sealed glass tube by heating with an electric furnace. The yields of the products were determined by gas-liquid chromatography (GLC) on OV-17 using pentadecane as an internal standard on the basis of the starting silacyclopropenes. Analytical samples were isolated by recycling high-pressure liquid chromatography (HPLC). 'H, I3C, and 29SiNMR spectra were measured with JEOL JNMEX-270 and Bruker AM-X-400 spectrometers. Infrared spectra were recorded on a Perkin-Elmer 1600-FT-IR spectrophotometer. Mass spectra were recorded on Shimadzu Model GCMS QP-1000 and Hitachi M-80B spectrometers. X-ray Analysis of 6a and 7b. Colorless crystals of 6a and 7b were obtained by recrystallization from ethanol. The experimental conditions and summary of structural refinement for 6a and 7b are listed in Table 2. The X-ray diffraction data were collected with a Rigaku AFC-6C automated four-circle
Organometallics, Vol. 14,No. 3, 1995 1209
Silicon-Carbon Unsaturated Compounds
Table 4. Selected Bond Lengths (A) and Bond Angles (deg) for 6a with Their ESDs in Parentheses
Table 3. Atomic Coordinates and Equivalent Isotropic Thermal Parameters (A*) for 6a with ESDs in Parentheses ~
atom
X
Y
Z
Si(1) Si(2) Si(3) Si(4) C(5) C(6) C(7) C(8) C(9) C(10) C(11) C(12) C(13) C( 14) C(15) C( 16) C( 17) C(18) C(19) C(20) C(21) C(22) C(23) C(24) C(25) C(26) C(27) C(28) C(29) C(30) C(31) C(32) C(33) C(34) C(35) C(36) C(37) C(38)
0.30402(5) 0.44635(5) 0.36267(5) 0.23458(6) 0.28360(19) 0.27058(18) 0.32162(18) 0.34299(19) 0.33676(22) 0.36113(26) 0.38881(29) 0.39457(25) 0.37096(19) 0.37091(18) 0.21139(19) 0.188 1l(22) 0.13220(25) 0.09978(25) 0.12236(25) 0.17845(20) 0.40087(20) 0.40268(23) 0.43232(28) 0.45975(28) 0.45548(29) 0.42570(25) 0.37262(29) 0.49158(40) 0.42170(47) 0.23929(25) 0.36248(25) 0.29322(26) 0.45820(25) 0.46944(23) 0.49662(25) 0.16911(50) 0.21491(81) 0.27255(53)
0.4257(1) 0.3492(1) 0.3487(1) 0.2921(1) 0.3345(4) 0.3766(4) 0.4156(4) 0.5176(4) 0.6194(4) 0.7037(5) 0.6891(5) 0.5828(6) 0.4966(4) 0.3334(4) 0.3993(4) 0.4980(5) 0.5199(6) 0.4374(7) 0.3388(7) 0.3178(5) 0.2610(5) 0.1516(6) 0.0818(7) 0.1246(8) 0.2295(8) 0.2984(7) 0.0993(5) 0.0399(11) 0.4142(8) 0.5045(6) 0.4898(5 ) 0.2878(5) 0.2697(6) 0.4920(5) 0.2929(8) 0.3667(11) 0.1585(10) 0.2872(20)
0.9799(1) 1.1585(1) 1.3475(1) 1.4220(1) 1.3193(4) 1.2102(4) 1 1480(4) 1.2154(4) 1.1699(5) 1.2370(6) 1.3459(7) 1.3985(5) 1.3332(4) 1.1870(4) 1.1544(4) 1.1664(6) 1.1176(7) 1.0586(7) 1.0475(6) 1.0952(5) 1.4661(4) 1.4437(5) 1.5291(7) 1.6363(6) 1.6583(6) 1.5776(5) 1.3302(6) 1.7219(8) 1.6128(7) 0.9182(5) 0.9 120(5) 0.9248(5) 1.0292(6) 1.1454(6) 1.2839(7) 1.4113(12) 1.3957(13) 1.5685(9)
a
+
Be, = (4/3)(Biin2 Bz2b2 -I- B33c2
I
4.31(6) 4.96(6) 4.15(6) 5.14(6) 4.15(13) 3.86(12) 3.77(12) 4.33( 14) 5.03( 15) 6.23(20) 6.96(22) 6.23( 19) 4.41(14) 3.78(12) 4.20(13) 5.50( 17) 6.90(21) 7.74(26) 7.15(23) 5.45(17) 4.98(16) 5.96(18) 7.77(24) 7.90(26) 7.93(27) 6.71(21) 6.65(20) 11.84(40) 10.58(36) 6.22(19) 6.17(18) 5.91(18) 7.13(22) 6.26(19) 8.24(26) 14.58(53) 19.94(84) 21.50( 104)
+ B I ~ U C p). COS
Figure 2. ORTEP view of 6a, showing the atom-numbering scheme. diffractometer using graphite-monochromatized Cu Ka radiation (1= 1.5418A). The structures were solved by the MonteCarlo direct method,I8 using the MULTAN78 program systemIg for the selection of the initial set of phase, and refined by the full-matrix least-squares program with analytical absorption correction.20 Atomic scattering factors were taken from International Tables for X-ray Crystallography.21 Aniso(18)Furusaki, A. Acta Crystallogr., Sect. A 1979,35,220. (19) Main, P.; Hull, S. E.; Lessinger, L.; Germain, G.; Declarcq, J.P.; Woolfson, M. MULTAN78, A System of Computer Programs for the Automatic Solution of Crystal Structures from X-Ray Diffraction Data; University of York, England and Louvain, Belgium, 1978. (20) Katayama, C.; Sakabe, N.; Sakabe, K. Acta Crystallogr., Sect. A 1972,28, S207.
~~
~
~
~
Bond Lengths Si(l)-C(7) 1.921(5) C(18)-C(19) 1.375(12) C(7)-C(14) Si(3)-C(5) 1.881(5) C(21)-C(22) 1.412(10) C(8)-C(13) Si(3)-C(14) 1.898(5) C(22)-C(23) 1.428(10) C(l0)-C(11) Si(4)-C(5) 1.868(5) C(23)-C(24) 1.414(10) C(12)-C(13) C(6)-C(7) 1.587(7) C(24)-C(28) 1.573(14) C(15)-C(20) C(7)-C(8) 1.552(7) C(26)-C(29) 1.529(13) C(17)-C(18) C(8)-C(9) 1.392(7) Si(2)-C(14) 1.896(5) C(19)-C(20) C(9)-C(10) 1.392(8) Si(3)-C(13) 1.894(6) C(21)-C(26) C(ll)-C(12) 1.475(10) Si(3)-C(21) 1.886(6) C(22)-C(27) C(15)-C(16) 1.385(8) C(5)-C(6) 1.356(7) C(24)-C(25) C(16)-C(17) 1.399(8) C(6)-C(15) 1.493(6) C(25)-C(26) C(5)-Si(3)-C(13) C(5)-Si(3)-C(21) C(13)-Si(3)-C(21) Si(3)-C(5)-Si(4) Si(4)-C(5)-C(6) C(5)-C(6)-C(15) Si(l)-C(7)-C(6) Si(l)-C(7)-C(l4) C(6)-C(7)-C(14) C(7)-C(8)-C(9) C(9)-C(8)-C(13) C(9)-C(lO)-C(ll) C(ll)-C(l2)-C(l3) Si(3)-C(13)-C(12) Si(2)-C(14)-Si(3) Si(3)-C(14)-C(7) C(6)-C(l5)-C(20) C(15)-C( 16)-C(17) C(17)-C( 18)-C(19) C(15)-C(2O)-C(19) Si(3)-C(21)-C(26) C(21)-C(22)-C(23) C(23)-C(22)-C(27) C(23)-C(24)-C(25) C(25)-C(24)-C(28) C(21)-C(26)-C(25) C(25)-C(26)-C(29)
Bond Angles 101.2(2) C(5)-Si(3)-C(14) 115.8(2) C(13)-Si(3)-C(14) 126.9(2) C(14)-Si(3)-C(21) 129.2(3) Si(3)-C(5)-C(6) 128.4(4) C(5)-C(6)-C(7) 123.0(4) C(7)-C(6)-C(15) 114.2(3) Si(l)-C(7)-C(8) 111.6(3) C(6)-C(7)-C(8) 105.0(4) C(8)-C(7)-C(14) 125.0(4) C(7)-C(8)-C(13) 122.2(5) C(8)-C(9)-C(lO) 121.3(6) C(l0)-C(l1)-C(l2) 119.2(5) S1(3)-C(13)-C(8) 140.0(4) C(8)-C(13)-C(12) 113.6(2) Si(2)-C(14)-C(7) 91.4(3) C(6)-C(15)-C(16) 119.4(5) C(16)-C(15)-C(20) 121.0(5) C(16)-C( 17)-C(18) 121.4(6) C(18)-C(19)-C(20) 119.0(6) Si(3)-C(21)-C(22) 12335) C(22)-C(21)-C(26) 120.5(6) C(21)-C(22)-C(27) 115.9(6) C(22)-C(23)-C(24) 119.9(7) C(23)-C(24)-C(28) 126.3(7) C(24)-C(25)-C(26) 120.0(7) C(21)-C(26)-C(29) 118.2(6)
1.588(6) 1.443(6) 1.339(10) 1.395(8) 1.410(7) 1.412(11) 1.398(8) 1.412(8) 1.543(9) 1.360(15) 1.390(11) 94.2(2) 89.4(2) 122.3(2) 101.9(4) 117.1(4) 119.5(4) 117.0(3) 104.5(4) 103.3(3) 112.8(4) 119.3(5) 120.8(6) 103.0(4) 117.0(5) 124.7(3) 120.2(4) 120.3(4) 117.9(7) 120.4(7) 118.1(4) 118.3(6) 123.6(5) 118.7(8) 113.8(9) 122.3(7) 121.9(6)
tropic temperature factors were used for refinement. Hydrogen atoms were not included in the refinement for 6a but included in that for 7b. The final atomic coordinates and equivalent isotropic temperature factors are given in Tables 3 and 5. ORTEP views of the molecular structure were shown in Figures 2 and 3,22and selected bond distances and angles are listed in Tables 4 and 6.23324 Materials. Solvent hexane was dried over lithium aluminum hydride and distilled before use. Silacyclopropene l a was prepared by the photolysis of 2-mesityl-2-(phenylethynyl)hexamethyltrisilane in hexane, as described in the previous paper.' Silacyclopropenes l b and IC were prepared by the similar photolysis of 2-(phenylethynyl)-2-o-tolylhexamethyltrisilane and 2-(phenylethynyl)-2-p-tolylhexamethyltrisilane in 41-46% and 25-36% yields, respectively. After evaporation of the solvent, the silacyclopropene thus obtained was transferred directly into the reaction tube by vacuum distillation.'l For lb: IH NMR (6 in C6D6) 0.24 (s, 9H, SiMes), 0.38 (s, 9H, SiMea), 2.53 (s, 3H, Me), 7.01-7.83 (m, 9H, aromatic ring H); l3C NMR (6 in C6D6) -0.14, 0.28 (SiMea), 24.1 (Me), 125.5, 128.6, 128.9, 129.6, 129.7, 130.1, 136.4 (aromatic ring CH), 136.1,136.6,143.6,151.7,169.2 (ipso and olefinic C); 29SiNMR (6 in C&) -115.3 (ring si),-14.2, -4.8 (SiMe,); MS m / z 366 (M+), 351 (M+ - CH3); HRMS m / z calcd for C21H30Si3 (21) International Tables for X-Ray Crystallography; Kynoch Press: Birmingham, U.K., 1974; Vol. 4. (22) Johnson, C. K. ORTEP; Report ORNL-3794; Oak Ridge National Laboratory, Oak Ridge, TN, 1965. (23) All computations were performed on the HITAC M-680/180E system a t the Information Processing Center of Hiroshima University using the CRYSTAN program system.24 (24) Katayama, C.; Honda, M. CRYSTAN, The Computer Center of Nagoya University Library Program, 1985.
Kunai et al.
1210 Organometallics, Vol. 14,No. 3, 1995
Table 5. Atomic Coordinates and Equivalent Isotropic Thermal Parameters (AZ)for 7b with ESDs in Parentheses atom
X
Y
Z
0.76214(6) 0.8959( 1) 0.6432(1) 0.73349(7) 0.845l(3) 0.8669(2) 0.6948(3) 0.6889(3) 0.7105(4) 0.7409(7) 0.6893(8) 0.6187(9) 0.5817(6) 0.6275(7) 0.8139(7) 0.942 l(3) 1.0035(4) 1.0736(4) 1.0859(4) 1.0262(4) 0.9538(3) 0.6429(3) 0.6807(4) 0.6424(6) 0.5680(7) 0.5304(5) 0.5682(4) 0.929( 1) 0.9852(7) 0.831 l(6) 0.6329(4) 0.7146(9) 0.541( 1) 0.7415(5) 0.8315(4) 0.6712(5)
0.3585( 1) 0.5882(2) 0.6164(2) 0.2645(2) 0.4614(5) 0.3543(5) 0.452 l(6) 0.418 l(6) 0.2258(6) 0.1469(8) 0.037( 1) 0.031(1) 0.112(2) 0.2017(9) 0.153( 1) 0.2932(5) 0.3784(7) 0.321( 1) 0.180(1) 0.0929(8) 0.1482(6) 0.5226(7) 0.6422(7) 0.73 lO(8) 0.701( 1) 0.586( 1) 0.4903(9) 0.743 1) 0.505(2) 0.644(2) 0.578( 1) 0.7701(9) 0.648(4) 0.1009(7) 0.3150(9) 0.212(1)
0.52050(6) 0.65511(9) 0.45853(9) 0.35028(7) 0.5828(2) 0.5520(2) 0.4369(3) 0.3754(4) 0.5502(3) 0.6089(5) 0.6250(6) 0.5766(6) 0.5120(8) 0.5020(8) 0.6591(5) 0.5610(3) 0.5666(4) 0.5747(5) 0.5813(4) 0.5768(4) 0.5646(3) 0.3130(3) 0.3042(3) 0.2470(4) 0.1999(4) 0.2067(4) 0.2635(4) 0.6183(8) 0.7210(6) 0.6905(6) 0.5409(4) 0.4790(7) 0.3900(6) 0.4014(4) 0.3585(4) 0.2565(4)
' B e , = ( 4 / 3 ) ( B i l ~i-z B22b2
B," 5.03(3) 7.95(6) 8.17(6) 6.15(4) 5.4(2) 5.1(2) 6.7(2) 7.4(2) 7.5(2) 11.7(4) 13.4(6) 15.0(6) 18.2(7) 14.8(6) 13.2(5) 5.6(2) 9.0(3) 11.8(4) 10.4(3) 8.7(3) 6.9(2) 7.4(2) 7.6(2) 9.9(3) 10.5(4) 9.7(3) 933) 18.3(8) 15.4(6) 14.3(6) 9.8(3) 15.2(6) 20.6(9) 8.8(3) 9.0(3) 9.7(3)
+ B3g2 i- B i s ~ ccos p).
366.1653, found 366.1574. For IC: 'H NMR (6 in C&) 0.32 (s, 9H, SiMea), 0.39 (s, 9H, SiMes), 2.10 (s, 3H, Me), 7.007.80 (m, 9H, aromatic ring H); 13CNMR (6 in C6D6) 0.19, 0.42 (SiMea), 21.4 (Me), 128.6, 128.8, 129.1, 130.1, 134.8 (aromatic ring CH), 132.2, 135.9, 139.2, 149.7, 166.1 (ipso and olefinic C); 29SiNMR (6 in C6D6) -120.1 (ring Si), -11.4, -9.9 (SiMe3); MS mlz 366 (M+), 351 (M+ - CH3); HRMS mlz calcd for CzlH30Si3 - CH3 351.1419, found 351.1337. Thermolysis of lb. A mixture of 0.34 mmol of lb and 0.71 mmol of pentadecane as an internal standard was heated in a sealed tube a t 130 "C for 6 h. The mixture was analyzed by GLC as being 2b (7%),3b (58%),and 4b (5%). 2b,3b,and 4b were isolated by recycling HPLC. For 2b: IR 2112 (YSi-H) cm-'; 1H NMR (6 in CDC13) -0.29 (s,9H, SiMes), -0.08 (s,3H, SiMe), -0.05 (dd, lH, HCH, J = 14.5 Hz, J = 2.5 Hz), 0.22 ( 8 , 3H, SiMe), 0.23 (dd, lH, HCH, J = 14.5 Hz, J = 4.3 Hz), 2.48 (9, 3H, Me), 5.19 (dd, lH, SiH, J = 4.3 Hz, J = 2.5 Hz), 6.977.55 (m, 9H, phenyl and tolyl H); 13CNMR (6 in CDCl3) -6.6 (SiCHzSi), -0.8 (SiMe), -0.5 (SiMe), 0.8 (SiMes), 22.5 (Me), 125.0, 125.6, 125.9, 127.1, 127.8, 129.5, 136.1, 136.6, 143.5, 146.6 (aromatic ring carbons), 161.3, 185.3 (olefinic carbons); MS m l z 366 (M+). Anal. Calcd for C21H30Si3: C, 68.78; H, 8.25. Found: C, 68.51; H, 8.46. For 3b: IR 1438 (vc-c), 1247 (v5i-c) cm-l; 'H NMR (6 in CDC13) 0.07 ( 8 , 9H, SiSiMes), 0.32 (s,9H, C(B)-SiMea),2.42 (s,3H, Me), 7.03 (8,lH, C(2)-H), 7.15 (t, l H , tolyl m-H, J = 7.5 Hz), 7.16 (d, lH, tolyl m'-H, J = 7.5 Hz), 7.24 (t, lH, C(6)-H, J = 7.5 Hz), 7.27 (td, lH, tolylp-H, J = 7.5 Hz, J = 1.5 Hz), 7.36 (td, l H , C(5)-H, J = 7.5 Hz, J = 1.5 Hz), 7.55 (d, l H , tolyl 0-H, J = 7.5 Hz), 7.67 (d, lH, C(4)H, J = 7.5 Hz), 7.76 (d, l H , C(7)-H, J = 7.5 Hz); 13C NMR (6 in CDC13) -1.33 (SiSiMes), -0.54 (C(3)-SiMe3),23.4 (Me), 125.1, 125.5, 125.8, 128.8, 129.4 (two), 133.3, 135.9, 143.6 (aromatic ring CHI, 132.9,139.1, 144.1, 152.5, 165.6 (ipso and fused C); MS m l z 366 (M+). Anal. Calcd for C21H30Si3: C,
68.78; H, 8.25. Found: C, 68.79; H, 8.27. For 4b: IR 2125 ( Y S ~ - H ) ,1248 (vsi-c) cm-l; 'H NMR (6 in CDCl3) 0.19 (s, 9H, C(2)-SiMes),0.45 (s,9H, C(B)-SiMea),2.08 (s,3H, Me), 5.15 (s, lH, SiH), 7.10 (d, l H , tolyl m'-H, J = 7.5 Hz), 7.18 (t, lH, tolyl m-H, J = 7.5 Hz), 7.20 (t, lH, C(6)-H, J = 7.5 Hz), 7.31 (td, 1H, tolylp-H, J = 7.5 Hz, J = 1.5 Hz), 7.37 (td, lH, C(5)-H,J =7.5Hz,J=1.5Hz),7.59(d, lH,toly10-H,J=7.5Hz),7.70 (2d, 2H, C(4)-H and C(7)-H,J = 7.5 Hz); 13CNMR (6 in CDC13) 2.50 (C(B)-SiMea),2.75 (C(2)-SiMe3),21.3 (Me), 125.2, 126.1, 126.5, 129.5, 129.6, 130.2, 132.5, 137.8 (aromatic ring CHI, 132.0,136.3, 144.9, 155.4, 158.2, 176.9 (ipso and fused C); MS mlz 366 (M+). Anal. Calcd for C21H30Si3: C, 68.78; H, 8.25. Found: C, 68.51; H, 8.30. Thermolysis of IC. A mixture of 0.24 mmol of IC and 0.94 mmol of pentadecane as an internal standard was heated in a sealed tube at 130 "C for 6 h. The mixture was analyzed by GLC as being 2c (ll%), 3c (36%), and 4c (9%). Compounds 2c,3c,and 4c were isolated by recycling HPLC. For 2c: IR 2113 (YQi-H), 1245 (vsi-c) cm-l; 'H NMR (6 in CDC13) -0.31 (s, 9H, SiMea), -0.11 (dd, lH, HCH, J = 14.9 Hz, J = 1.7 Hz), 0.13 (9, 3H, SiMe), 0.19 (dd, l H , HCH, J = 14.9 Hz, J = 4.3 Hz), 0.20 (s, 3H, SiMe), 2.38 (s, 3H, Me), 5.11 (dd, lH, SiH, J = 4.3 Hz, J = 1.7 Hz), 6.96-7.48 (m, 9H, aromatic ring H); 13CNMR (6 in CDCl3) -5.68 (SiCHZSi), -0.63 (two SiMe), 0.85 (SiMea), 21.5 (Me), 125.6, 126.0, 127.7, 128.7, 134.7 (aromatic ring CH), 134.4, 139.1, 146.6, 160.9, 185.3 (olefinic and ipso C); MS mlz 366 (M+). Anal. Calcd for C21H30Si3: C, 68.78; H, 8.25. Found: C, 68.55; H, 8.15. For 3c: IR 1438 (vc-c), 1247 (vsi-c) cm-l; 'H NMR (6 in CDCl3) 0.10 (s, 9H, SiSiMea), 0.30 (s,9H, C(3)-SiMe3),2.31 (s, 3H, Me), 6.93 (s, l H , C(2)-H), 7.13 (d, 2H, tolyl m-H, J = 7.5 Hz), 7.20 (t, lH, C(6)-H, J = 6.5 Hz), 7.34 (t, l H , C(5)-H, J = 7.5 Hz), 7.42 (d, 2H, tolyl 0-H, J = 7.5 Hz), 7.52 (d, l H , C(4)-H, J =7.5 Hz), 7.65 (d, lH, C(7)-H, J = 6.5 Hz); 13C NMR (6 in CDC13) -1.53 (SiSiMes), -0.54 (C(3)-SiMe3), 21.5 (Me), 125.3, 125.9, 128.93, 132.8, 135.0, 139.2, 143.7 (aromatic ring CH), 123.7, 128.84, 128.88, 156.7, 165.9 (ipso and fused C); MS mlz 366 (M+). Anal. Calcd for Cz1H30Si3: C, 68.78; H, 8.25. Found: C, 68.78; H, 8.24. For 4c: IR 2126 (vs~-H), 1248 (vsi-c) cm-l; 'H NMR (6 in CDC13)0.19 (s, 9H, C(2)-SiMes),0.46 (s, 9H, C(3)-SiMe3),2.35 (s, 3H, Me), 5.14 (s, lH, SiH), 7.15 (d, 2H, tolyl m-H, J = 7.5 Hz), 7.16 (t, l H , C(6)-H,J = 7.5 Hz), 7.35 (t, lH, C(5)-H, J = 7.5 Hz), 7.40 (d, 2H, tolyl 0-H, J 7.5 Hz), 7.56 (d, l H , C(4)H, J = 7.5 Hz), 7.66 (d, lH, C(7)-H,J = 7.5 Hz); 13CNMR (6 in CDC13) 2.63 (C(2)-SiMea),2.86 (C(3)-SiMe3),21.6 (Me), 125.8, 126.5, 128.9, 129.5, 132.5, 135.3 (aromatic ring CHI, 128.8, 136.6, 139.8, 155.6, 158.1, 176.9 (ipso and fused C); MS mlz 366 (M+). Anal. Calcd for C21H30Si3: C, 68.78; H, 8.25. Found: C, 68.61; H, 8.08. Thermolysis of lb in the Presence of Phenyl(trimethylsily1)acetylene. A mixture of 0.43 mmol of lb,3.0 mmol of phenyl(trimethylsilyl)acetylene, and 0.94 mmol of pentadecane as an internal standard was heated in a sealed tube at 230 "C for 6 h. The mixture was analyzed by GLC as being 2b (ll%), 3b (4%),4b (17%), and 7b (44%). 7b was isolated by recycling HPLC. For 7b: IR 1480 (vc-c), 1247 (vsi-c) cm-l; 1H NMR (6 in CDCls) -0.58 (s,9H, =CPhSiMej), -0.41 (s, 9H, ring SiMes), -0.04 (s, 9H, =C(Si)SiMes), 2.67 (s, 3H, Me), 6.35-8.21 (m, 14H, aromatic ring H); 13C NMR (6 in CDC13) 0.11 (=CPhSiMea), 1.49 (ring SiMes), 1.64 (=C(Si)SiMea),24.0 (Me), 124.3, 125.2, 125.4, 126.6, 126.7, 127.5, 127.6, 127.7, 128.1, 129.8, 130.6, 132.8, 134.2, 135.0, 144.6, 145.2, 145.7, 157.4, 185.7 (aromatic and olefinic carbons); 29SiNMR (6 in C6D6) -104.7 (ring Si), -11.3, -7.3, -5.6 (SiMe3);MS mlz 540 (M+). Anal. Calcd for C32H4Si4: C, 71.04; H, 8.20. Found: C, 70.88; H, 8.11. Thermolysis of IC in the Presence of P h e n y l W m e t h ylsily1)acetylene. A mixture of 0.45 mmol of IC, 2.6 mmol of phenyl(trimethylsilyl)acetylene, and 1.2 mmol of pentadecane as an internal standard was heated in a sealed tube at 250 "C for 6 h. The mixture was analyzed by GLC as being 2c (5%),3c (2%), 4c (ll%), 8c (75%), and 9c (11%).8c and
Organometallics, Vol. 14,No.3, 1995 1211
Silicon-Carbon Unsaturated Compounds
Figure 3. ORTEP view (right) and the atom-numbering scheme (left) of 7b. In the view, an o-tolyl group on Si1 and a phenyl group on C8 are represented by single carbons, C9 and C22, respectively.
Table 6. Selected Bond Lengths (A) and Angles (deg) for 7b with Their Esd's in Parentheses Si(l)-C(5) Si(1)-C(7) Si(2)-C(5) Si(4)-C(8) C(6)-C(16) C(8)-C(22) C(9)-C(14) C(lO)-C(15) C(12)-C(13) C(16)-C(17)
1.834(4) 1.891(5) 1.848(5) 1.859(7) 1.470(7) 1.573(8) 1.48(1) 1.34(1) 1.45(2) 1.373(9)
C(5)-Si( 1)-C(6) C(5)-Si( 1)-C(9) C(6)-Si( 1)-C(9) Si(l)-C(5)-Si(2) Si(2)-C(5)-C(6) Si(l)-C(6)-C(l6) Si( 1)-C(7)-Si(3) Si(3)-C(7)-C(8) Si(4)-C(8)-C(22) Si(l)-C(9)-C(lO) C(IO)-C(9)-C(14) C(9)-C(lO)-C(15) C(lO)-C(ll)-C(12) C(12)-C(13)-C(14) C(6)-C(16)-C(17) C(17)-C( 16)-C(21) C(17)-C(18)-C(19) C(19)-C(2O)-C(21) C(8)-C(22)-C(23) C(23)-C(22)-C(27) C(23)-C(24)-C(25) C(22)-C(27)-C(26)
Bond Lengths C(17)-C(18) 1.37(1) C(19)-C(20) 1.37(1) C(22)-C(23) 1.39(1) C(23)-C(24) 1.39(1) C(25)-C(26) 1.33(2) 1.801(4) Si(1)-C(6) 1.848(7) Si(1)-C(9) 1.981(6) Si(3)-C(7) C(5)-C(6) 1.352(7) C(7)-C(8) 1.29(1)
C(9)-C(10) C(lO)-C(ll) C(l1)-C(12) C(13)-C(14) C(16)-C(21) C(18)-C(19) C(20)-C(21) C(22)-C(27) C(24)-C(25) C(26)-C(27)
Bond Angles 43.7(2) C(5)-Si(l)-C(7) 122.2(3) C(6)-Si(l)-C(7) 121.1(2) C(7)-Si(l)-C(9) 156.3(4) Si( 1)-C(5)-C(6) 135.8(3) Si( 1)-C(6)-C(5) 155.2(4) C(5)-C(6)-C(16) 110.9(3) Si( l)-C(7)-C(8) 125.6(4) Si(4)-C(8)-C(7) 114.2(5) C(7)-C(8)-C(22) 127.0(6) Si(l)-C(9)-C(l4) 117.4(9) C(9)-C(lO)-C(ll) 127(1) C(ll)-C(lO)-C(l5) 113(1) C(l l)-C(l2)-C(l3) 114(1) C(9)-C(14)-C(13) 121.1(5) C(6)-C(16)-C(21) 117.8(5) C(16)-C(17)-C(18) 121.0(8) C(l8)-C(19)-C(20) 120.6(7) C(16)-C(21)-C(20) 119.0(4) C(8)-C(22)-C(27) 119.9(6) C(22)-C(23)-C(24) 120.0(8) C(24)-C(25)-C(26) 118.6(8)
1.34(1) 1.56(2) 1.29(2) 1.29(2) 1.381(8) 1.35(1) 1.38(1) 1.385(8) 1.36(1) 1.42(1) 116.7(2) 123.6(3) 112.5(3) 66.9(3) 69.5(3) 134.8(4) 123.4(5) 128.3(5) 117.3(5) 115.6(6) 120.3(9) 113.0(9) 130(1) 125(1) 121.2(5) 121.1(6) 119.1(8) 120.3(6) 120.9(6) 119.7(6) 121.6(8)
9c were isolated by recycling HPLC. For 8c: IR 1249 (vsi-c) cm-l; lH NMR (6 in CDC13) -0.29 (s, 9H, =CPhSiMea), 0.38 (s, 9H, C(S)-SiMes),0.44 (s, 9H, =C(Si)SiMea), 2.31 (s,3H, Me),
7.12 (d, 2H, tolyl m-H, J = 7.5 Hz), 7.15-7.35 (m, 7H, C(5)-H, C(6)-H, phenyl o-, m-,p-H),7.55 (d, 2H, tolyl o-H, J = 7.5 Hz), 7.61 (d, lH, C(7)-H, J = 7.5 Hz), 7.64 (d, lH, C(4)-H, J = 7.5 Hz), 8.05 (s, l H , C(3)-H); I3C NMR (6 in CDCl3) 1.48, 2.81, 3.90 (&Mea),21.5 (Me), 126.0,126.3,127.3,127.5,127.8,128.6, 129.0, 132.3, 135.6 (aromatic ring CHI, 131.2, 139.1, 140.1, 140.2,142.6 (ipso and fused C), 154.6 (C(2)),162.2 (C(3)),160.3, 176.4 (olefinic C); 29Si NMR (6 in C&) -10.0, -7.7, -6.2 (SiMes), 4.5 (ring Si); MS mlz 540 (M+). Anal. Calcd for
Ca2HUS4: C, 71.04; H, 8.20. Found: C, 71.00; H, 8.20. ForSc: IR 1544 (vc=c), 1246 (v~i-c)cm-l; lH NMR (6 in CDC13) -0.08 (s, 9H, =CPhSiMez), -0.05 (s, 9H, C(S)-SiMea),0.28 (s, 9H, =C(Si)SiMea),2.28 (s, 3H, Me), 6.71 (d, 2H, phenyl o-H, J = 7.5 Hz), 6.94 (t, 2H, phenyl m-H, J = 7.5 Hz), 7.01 (d, 2H, tolyl m-H, J = 7.5 Hz), 7.03 (t, l H , phenyl p-H, J = 7.5 Hz), 7.27 (t, lH, C(6)-H, J = 7.5 Hz), 7.38 (t, l H , C(5)-H, J = 7.5 Hz), 7.43 (d, 2H, tolyl 0-H, J = 7.5 Hz), 7.62 (d, l H , C(7)-H, J = 7.5 Hz), 7.75 (d, l H , C(4)-H, J = 7.5 Hz), 7.80 (s, lH, C(3)H); NMR (6 in CDC13) 1.15, 2.77, 3.22 (SiMea), 21.5 (Me), 126.2, 126.3, 127.3 (two), 128.1, 128.3, 128.8, 132.5, 135.9 (aromatic ring CH), 131.6, 138.8, 139.7, 140.6, 141.1 (ipso and fused C), 155.2 (C(3)), 158.5 (C(2)), 163.6, 171.1 (olefinic C); MS mlz 540 (M+);HRMS mlz calcd for C32H44Si4 540.2517, found 540.2485. Thermolysis of lb in the Presence of Methyldiphenylsilane. A mixture of 0.34 mmol of lb,2.7 mmol of methyldiphenylsilane, and 0.94 mmol of pentadecane as an internal standard was heated in a sealed tube at 250 "C for 6 h. The mixture was analyzed by GLC as being 2b (9%),3b (6%), 4b (13%),10b (14%), and llb (10%). 10b and Ilb were isolated by recycling HPLC. Since all attempts to separate 10b from llb using recycling HPLC were unsuccessful, samples containing a small amount of the other isomer were subjected to spectrometric and elemental analysis. For a mixture of 10b and Ilb: IR 2137 (v~i-~),1246 (v~i-c)cm-l; 'H NMR (6 in CDC13)-0.41, -0.23, -0.08, 0.24 (s, 9H, SiMea), 0.46,0.90 (s, 3H, SiMe), 2.13,2.40 (s, 3H, Me), 5.43,5.51 (s, lH, SiH), 6.847.69 (m, 19H, aromatic ring H); NMR (6 in CDC13) -3.56, -1.38 (SiPhae), 2.05,2.90,2.99,3.76 (SiMea),23.2,23.9 (Me), 124.7, 124.8, 125.5, 126.8, 127.1, 127.2, 127.3, 127.7, 127.82, 127.85, 127.89, 128.75, 128.79, 128.9, 129.0, 129.1, 129.3, 129.5, 129.7, 135.0, 135.2, 135.5, 135.6, 137.5 (aromatic ring CH), 132.9, 134.5, 137.0, 137.2, 137.3, 137.7, 144.3, 144.5, 149.0, 149.7 (ipso C), 154.3, 169.1, 171.5, 182.4 (olefinic C). S~ 72.27; : H, 7.85. Found: C, 72.24; Anal. Calcd for C ~ ~ H U C, H, 7.85. For lob: lH NMR (6 in CDC13) -0.41 (9, 9H, =CPhSiMes), -0.08 (s, 9H, =C(Si)SiMea), 0.90 ( 6 , 3H, SiMe), NMR (6 in CDC13) -1.38 2.40 (s, 3H, Me), 5.51 (s, l H , SiH); ( S i P h a e ) , 2.05, 2.90 (SiMes), 23.9 (Me); MS mlz 564 (M+). For llb: lH NMR (6 in CDC13) -0.23 (s, 9H, =CPhSiMed, 0.24 (s,9H, =C(Si)SiMea),0.46 (s, 3H, SiMe), 2.13 (s, 3H, Me), 5.43 ( 6 , lH, SiH); I3C NMR (6 in CDC13) -3.56 (SiPhfle), 2.99, 3.76 (SiMes), 23.2 (Me); MS mlz 564 (M?. Thermolysis of IC in the Presence of Methyldiphenylsilane. A mixture of 0.44 mmol of lb, 3.9 mmol of methyl-
Kunai et al.
1212 Organometallics, Vol. 14,No. 3, 1995 diphenylsilane, and 1.2 mmol of pentadecane as an internal standard was heated in a sealed tube at 250 "C for 6 h. The mixture was analyzed by GLC as being 2c (2%),3c (3%), 4c (4%), 1Oc (60%),and llc (18%). 1Oc and llc were isolated by recycling HPLC, followed by recrystallization from ethanol. For 1Oc: IR 2148 (vQ~-H), 1244 (vgi-c) cm-'; lH NMR (6 in CDC13)-0.45 (s, 9H, =CPhSiMej), -0.05 (s,9H, =C(Si)SiMea), 0.89 (5, 3H, SiMe), 2.34 (s, 3H, Me), 5.44 (s, lH, SiH), 6.787.71 (m, 19H, aromatic ring H); I3C NMR (6 in CDC13) -1.90 ( S i P h a e ) , 2.18, 2.63 (SiMes), 21.5 (Me), 125.5, 126.7, 127.3, 127.4, 127.8, 127.9, 128.8, 129.0, 129.1, 135.4, 135.7, 135.8 (aromatic ring CH), 131.1, 137.1, 137.7, 138.8, 149.2 (ipso C), 153.5, 183.7 (olefinic C); MS m l z 564 (M+). Anal. Calcd for C34H~Si4:C, 72.27; H, 7.85. Found: C, 72.08; H, 7.78. For llc: IR 2148 ( Y S ~ - H ) , 1244 (vsi-c) cm-l; lH NMR (6 in CDCl3) -0.24 (s, 9H, =CPhSiMej), 0.30 (s, 9H, =C(Si)SiMea), 0.45 (8, 3H, SiMe), 2.30 (9, 3H, Me), 5.33 (s, l H , SiH), 7.00-7.50 (m, 19H, aromatic ring H); 13CN M R (6 in CDC13) -3.86 (SiPh&fe), 2.75, 4.06 (SiMes), 21.4 (Me), 126.6, 127.71, 127.76, 127.80, 128.4, 128.6, 128.8, 129.0, 135.1, 135.3, 136.2 (aromatic ring CH), 129.4, 136.9, 137.1, 138.7, 149.2 (ipso C), 168.1, 171.1
(olefinic C); MS m l z 564 (M+). Anal. Calcd for C34H44Si4: C, 72.27; H, 7.85. Found: C, 72.08; H, 7.78.
Acknowledgment. This research was supported in part by a Grant-in-Aid on Priority Area of Reactive Organometallics (05236102) from the Ministry of Education, Science and Culture, to which our thanks are due. We also express our appreciation to Shin-Etsu Chemical Co. Ltd., Nitto Electric Industrial Co. Ltd., Dow Corning Asia Ltd., Toshiba Silicone Co. Ltd., Sumitomo Electric Co. Ltd., Kaneka Corp., and Japan High Polymer center for financial support. Supplementary Material Available: Tables of bond distances and angles and anisotropic thermal parameters for 6a and 7b and an ORTEP view of 7b with full carbons (10 pages). Ordering information is given on any current masthead page. OM9406310
