Organometallics 1995, 14, 4570-4575
4570
Selective Hydrosilylation of Alkynes Catalyzed by an Organoyttrium Complex Gary A. Molander" and William H. Retsch Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215 Received April 28, 1995@ The organoyttrium complex Cp*2YCH3*THF(Cp* = C5Me5) has been shown to be an effective precatalyst for the hydrosilylation of internal alkynes. The reaction with symmetrically substituted alkynes results in a single stereoisomer as the product of cis addition of phenylsilane to the alkyne. The reaction of various unsymmetrically substituted internal alkynes results in a regioselective hydrosilylation reaction that places the silane at the less hindered carbon of the alkyne. A variety of functional groups, e.g., halides, amines, protected alcohols, and trisubstituted olefins, are tolerated by the reaction conditions with no decrease in yield. Introduction The formation of alkenylsilanes by the catalytic hydrosilylation reactions of terminal alkynes has much precedent in the literature, but similar reactions with internal alkynes are significantly less c0mmon.l Symmetrical internal alkynes can be hydrosilylated to yield a single product,2 but unsymmetrically substituted alkynes rarely react in a regioselective manner.3 The focus of the present research was to take advantage of the steric discrimination of an organoyttrium complex for the regioselective and stereoselective hydrosilylation of internal alkynes. The organoyttrium species Cp*2YCH(TMS)2 (Cp* = C5Me5) has been demonstrated to be an efficient precatalyst for the selective hydrosilylation of the less substituted olefin in a diene ~ u b s t r a t e .Similarly, ~ the organoyttrium hydride catalyst derived from Cp*zYCHyTHF has been shown to effect the hydrogenation of dienes in a selective mannera5 We now report that this latter complex also serves as an effective precatalyst for the regioselective hydrosilylation of internal unsymmetrical alkynes. Results and Discussion To be synthetically useful, a hydrosilylation procedure for internal alkynes would be expected to exhibit several distinguishing characteristics. First, the reaction must produce only one of two possible stereoisomers. Second, when the substrate is not symmetrically substituted, only one of two possible regioisomers should be formed. It would also be desirable if the process took place under relatively mild conditions a t a reasonable rate, and tolerated a variety of functional groups as well. The Abstract published in Advance ACSAbstracts, September 1,1995. (1)(a) Benkeser, R. A.; Burrows, M. L.; Nelson, L. E.; Swisher, J. V. J . A m . Chem. SOC.1961,83,4385. (b) Chalk, A.J.; Harrod, J. F. J. Am. Chem. SOC.1966,87, 16. (c) Benkeser, R. A,; Ehler, D. F. J. Organomet. Chem. 1974,69, 193. (d) Speier, J. L. Adv. Organomet. Chem. 1979, 17, 443-445. (e) Colvin, E. W. Silicon in Organic Synthesis; Butterworths: London, 1981;pp 45-48, 325-326. (2) Ryan, J. W.; Speier, J. L. J. Org. Chem. 1988,31,2698. (3) Stork, G.;Jung, M. E.; Colvin, E.; Noel, Y. J . Am. Chem. SOC. 1974,96,3684. (4)Molander, G.A.; Julius, M. J. Org. Chem. 1992,57,6347. (5) Molander, G.A.; Hoberg, J. 0. J . Org. Chem. 1992,57,3267.
results outlined in Table 1 illustrate examples of the organoyttrium-catalyzed hydrosilylation of various alkynes and provide evidence that this procedure successfully fulfills these requirements. The reaction of a symmetrical alkyne, 5-decyne, with 5 mol % of the precatalyst in the presence of phenylsilane cleanly produces the (23)-alkenylsilane as the sole product (entry 1). The stereochemistry of the double bond in the product was determined by an NOE difference experiment in which irradiation of the silane protons produced a 6% enhancement of the olefinic proton signal. The reaction of unsymmetrical alkynes (entries 2-12) generated not only a single stereoisomer but also cleanly formed only one regioisomer in high yield. The regiochemistry, in most cases, was determined by the splitting pattern of the olefinic proton resonances. The examples depicted in entries 3,4, and 9-12 demonstrate that a branching methyl group a t o the alkyne provides sufficient steric differentiation to provide complete regioselectivity in the hydrosilylation reaction. The reaction of these substrates with phenylsilane is generally complete within 24 h a t temperatures of 50 "C or less. The substrate depicted in entry 5 , which contained a tert-butyl group on the alkyne, required longer reaction times and provided lower yields of the desired product because of competing side reactions. Presumably, the bulk of the tert-butyl group slows down the desired reaction enough to permit the dehydrogenative polymerization6 of phenylsilane to compete with hydrosilylation. Additionally, the silane polymerization forms hydrogen gas that hydrogenates the starting material to provide an olefinic byproduct, lowering the yield of the alkenylsilane. Substrates with silyl ethers a to the alkyne (entries 6-8) required higher temperatures in order to react a t a sufficient rate but still reacted with complete selectivity. Substrates depicted in entries 6 and 7 reacted cleanly and provided very good yields of the expected (6)(a) Forsyth, C. M.; Nolan, S. P.; Marks, T. J. Organometallics 1991,10,2543.(b) Woo, H. G.; Walzer, J. F.; Tilley, T.D. J.Am. Chem. SOC.1992,114,7047.(c) Radu, N.S.; Tilley, T. D.; Rheingold, A. L. J. Am. Chem. SOC.1992,114,8293.
0276-7333/95/2314-4570$09.00/00 1995 American Chemical Society
Organometallics, Vol. 14, No. 10, 1995 4571
Hydrosilylation Catalyzed by Cp*zYCH3*THF
Table 1. Selective Hydrosilylation of Alkynes Catalyzed by Cp*2YCHs(THF) entry
substrate
product
readion % isolated tempera- ('C) li yield
R-R'
la R = n-butyl
R = n-butyl
2a
50
83
l b R = cyclohexyl
R = Me
2b
50
74
IC R = sec-butyl
R' = Me
2c
50
74
Id R = sec-butyl
R = n-pentyl
2d
40
93
le R = rert-butyl
R = ndecyl
2e
55
28
TBDMSO
)+R' R
3aR=Me
R=Me
40
90
82
3b R - M e
R=n-decyl
4b
90
89
3cR=H
R=Me
4c
90
23
9
Sa X = C 1
6a
50
79
10
5b X-OTHP
6b
50
84
11
Sc X=NM%
6c
so
73
8
so
80
12
7
*
a The reactions were run for 24 h at the specified temperature unless otherwise indicated. Refers to the yields of purified materials. 13C NMR, IR), and elemental composition has been established by highAll products have been fully characterized spectroscopically (lH, resolution mass spectrometry and/or combustion analysis. Reaction time 12 h. Reaction time 48 h. e Reaction time 17 h.
products, while the substrate in entry 8, differing only by the absence of a methyl group, reacted much more slowly and gave a lower yield. Alkynes 3, 6, and 7 (entries 6-12) demonstrate that the reaction is tolerant of a variety of functional groups. Even these oxygenand nitrogen-containing functional groups do not appreciably affect the reactivity of the Lewis acidic metal complex. Unsymmetrical alkynes that displayed less than complete selectivity in the hydrosilylation reaction are displayed in Table 2. The substrate in the first entry, 2-nonyne, affords two regioisomers under the reaction conditions. The ratio of products as determined by fused silica gas chromatographic analysis of the crude reaction mixture was 4.1:l. The olefinic proton resonances in
the 'H NMR spectrum support this determination and provide evidence that 10a is the major product. The olefinic proton resonance of the major product (loa) appears as a triplet of doublet^,^ while the olefinic proton resonance of the minor product (lob) appears as a quartet. The other three entries are alkynes substituted in the &position. Substrate 11 (entry 2) confirms that regioselectivity in methyl alkynes is reasonably high (7.3:l). The regioselectivity of the major product (12a) was determined by the lH NMR data in the same manner as that of 10a described above. The alkyne in entry 3 is symmetrical, with the exception (7) Appears as a triplet of doublets but is recognizable as a triplet of quartets in which the smaller peaks are not fully resolved.
4572 Organometallics, Vol. 14, No. 10,1995
Molander and Retsch
Table 2. Hydrosilylation of Alkynes Yielding Mixtures of Productp ratio major : minor
products entry
substrate
minor
major
H
1
9=
4.1 : 1 7.2: Id
10b
7 )=cc PhH2Si
2
SiH2Ph
11
H
H
SiHlph
1%
R
12b
w PhHgi
H
H
7.3: 1
SiH2Ph
3
13 R = M e
14a
14b
1:l
4
15 ReOCPh3
16s
16b
2.5 : 1
The reactions were run for 24 h at 50 "C using the Cp*2YCHs(THF)precatalyst unless otherwise indicated. All products have been characterized as mixtures by 'H, 13CNMR, and IR, and elemental composition has been established by high-resolution mass spectrometry and/or combustion analysis. Reaction temperature 40 "C. The precatalyst Cp*2YbCH(TMS)2was used.
of the ,%methylsubstituent. In this case, no selectivity was achieved and the product was a 1:l mixture of regioisomers. When a bulkier substituent was used in the B-position (e.g., triphenylmethoxy, entry 41, the regioselectivity improved slightly to 2.5:1, as determined by integration of the olefinic protons in the 'H NMR spectrum. The major product was determined by the diastereotopic protons on silicon in the IH NMR. The silane proton resonances of the major product (14a) appear as a singlet, and in the minor product (14b)they appear as an AB pattern owing to the proximity of the silicon t o the stereocenter. Some improvement in the regioselectivity was achieved when a precatalyst incorporating a lanthanide metal with a smaller ionic radius was used. Thus, Cp*2YbCH(TMSh was prepared and utilized in the hydrosilylation of substrates 9,11, 13, and 15 as outlined in Table 2. The regioselectivity for the reaction of phenylsilane with 2-nonyne (entry 1)using this precatalyst was improved from 4.1:l t o 7.2:l. This result can be attributed to the smaller ionic radius of ytterbium relative to that of yttrium. The smaller coordination sphere around the metal enhances the steric effects of the bulky organometallic complex, which improves the regioselectivity in the hydrosilylation reaction. Unfortunately, the selectivity of the reactions with alkynes substituted in the ,&position was not enhanced by the use of the ytterbium complex. A viable catalytic cycle, similar to the one proposed for the hydrosilylation of olefin^,^ is outlined for the hydrosilylation of an unsymmetrical alkyne in Scheme 1. A a-bond metathesis between Cp*2YCHyTHF and PhSiHs produces "Cp*2YH", initiating the proposed catalytic This reaction may occur through more than one pathway, but the end result is to produce a monomeric metal hydride species that serves as the active catalyst. Insertion of the alkyne into the metal-
Scheme 1 cp*2YMe.THF
WSM,
y I
RL=lprSesrarp RSr--
yI
hydride bond follows. The alkenylmetallic species produced by the insertion can react with P h S s through a a-bond metathesis reaction t o release the alkenylsilane and regenerate the active catalytic species. The alkyne insertion is both rapid and thermodynamically favorable,8while the a-bond metathesis step with phenylsilane appears to be the rate-limiting step. Attempts to use a bulkier silane in these reactions were unsuccessful. Thus, dimethylphenylsilane was unreactive with the alkynes under the reaction conditions. In summary, the organoyttrium complex Cp*2YCH3* THF can be used to catalyze the hydrosilylation of simple and functionalized unsymmetrical internal alkynes. The reaction proceeds under fairly mild condi(8)(a) den Haan, K. H.; Wielstra, Y.; Teuben, J. H. Organometallics 1987,6, 2053. (b) Nolan, S. P.; Porchia, M.; Marks, T. J. OrganomeTilley, T. D. J. Am. Chem. Soc. tallics 1991,10, 1450. ( c ) Woo, H.-G.; 1989,111, 8043. (d) Fu, P.-F.; Brard, L.; Marks, T. J. Abstracts of Papers, 207th National Meeting of the American Chemical Society, San Diego, CA, March 1994; American Chemical Society: Washington, DC, 1994; INOR 40.
Hydrosilylation Catalyzed by Cp*zYCH3*THF tions to produce a single regioisomer in many cases. The
Organometallics, Vol. 14, No. 10, 1995 4573 2130 cm-l; HRMS calcd for C l d b S i 246.1804, found 246.1805;
(E)-l-Cyclohexyl-2-(phenylsilyl)-l-propene (2b). Purification by flash chromatography and Kugelrohr distillation afforded 74% of the desired product (97% pure by GC analyAll operations were performed with rigorous exclusion of sis): ot 75-80 "C/0.25 mmHg; Rf0.46 (hexanes); lH NMR (400 oxygen and moisture in flamed Schlenk-type glassware on an MHz, CDC13) 6 1.06-1.30 (m, 5H), 1.61-1.70 (m with overlapargon line connected to a vacuum system (c0.04 mmHg) or in ping doublet at 1.73, J = 1.7 Hz, 8H), 2.38-2.41 (m, lH), 4.48 a nitrogen-filled Vacuum Atmospheres glovebox. (9, l J % g i , ~ = 194.5 Hz, 2H), 5.85-5.88 (m, lH), 7.23-7.38 (m, The cyclohexane for the reactions was distilled from NaLK 3H), 7.53-7.56 (m, 2H); 13CNMR (100 MHz, CDCl3) 6 15.57, alloyhenzophenone under argon and then stored in the 26.03, 26.20, 32.65, 37.89, 127.09, 128.72, 130.29, 133.15, glovebox. The alkynes 5-decyne, 1-cyclohexyl-1-propyne,and 136.29, 152.76; IR (neat) 2924, 2850, 2130, 1448, 1428, 862, 2-butyn-1-01were commercial samples dried over activated 4 836 cm-1; HRMS (EI) calcd for C15H22Si 230.1491, found molecular sieves, vacuum-transferred, and freeze/pump/ 230.1500; LRMS (EI) m / z (relative intensity) 230 (25), 188 thaw-degassed. The other alkynes were prepared from the (44), 152 (46), 147 (46), 123 (74), 107 (loo), 81 (87.4),67 (611, alkylation of 3-methyl-l-pentyne, 3,3-dimethyl-l-butyne, or 55 (541, 41 (42). (%)-3-butyn-2-01,using the appropriate alkyl halide.s Protect(E)-4-Methyl-2-(phenylsilyl)-2-hexene (24. Purification ing groups on the alcohols were installed according to pubby flash chromatography and Kugelrohr distillation afforded lished procedures.1° 8-(Dimethylamino)-3-methyl-4-nonyne 74% of the desired product (99% pure by GC analysis): ot 50(13c)was prepared from 13a by alkylation of dimethy1amine.l' 55 "C/0.15 mmHg; Rf 0.53 (hexanes); lH NMR (400 MHz, The products were dried over activated 4 A molecular sieves CDCl3) 6 0.87 (t, J = 7.4 Hz, 3H), 0.97 (d, J = 6.7 Hz, 3H), and degassed as above or on the vacuum line depending on 1.24-1.41 (m, 2H), 1.75 (d, J = 1.7 Hz, 3H), 2.47-2.55 (m, volatility. The phenylsilane was purchased from Aldrich and lH), 4.53 (9, 'Jz9S1,H = 194.9 Hz, 2H), 5.82 (dd, J = 1.61, 9.3 was freeze/pump/thaw-degassedbefore use. Anhydrous Ycl3 Hz, lH), 7.34-7.42 (m, 3H), 7.56-7.59 (m, 2H); 13CNMR (100 was puchased from Cerac. The complex Cp2*YCHyTHF was MHz, CDC4)S 11.97,15.63,20.17,29.88,34.69,126.94,127.96, prepared according to published procedures.12 Cpz*YbCH129.51, 132.36, 135.46, 152.23; IR (neat) 2131 cm-l; HRMS (TMS)z was prepared similarly to the literature preparation calcd for C13HZ0Si204.1334, found 204.1322; LRMS (EI) m / z of Cpz*LnCH(TMS)z(Ln = La, Nd, Sm, Lu).13 All compounds (relative intensity) 204 (25), 175 (121, 162 (771, 147 (76), 121 were stored in the glovebox after purification. (91), 107 (loo), 97 (77), 55 (671, 41 (29). Procedure for Catalytic Hydrosilylation of 5-Decyne (E)-3-Methyl-5-(phenylsilyl)-4-decene (2d). Purification (la). In the nitrogen atmosphere glovebox a solution of 0.009 by flash chromatography and Kugelrohr distillation afforded g (0.024 mmol) of the precatalyst Cp*2YCH3*THFin 1 mL of 93% of the desired product (299% pure by GC analysis): ot cyclohexane was added to a Teflon-valved Schlenk tube 80-86 W0.25 mmHg; Rf 0.64 (7% dichloromethane in hexequipped with a magnetic stirbar. To this solution was added anes); lH NMR (400 MHz, CDC13) 6 0.83 (t, J = 6.9 Hz, 3H), 0.072 g (0.52 mmol) of la followed by 0.129 g (1.01 mmol) of 0.85 (t, J = 7.5 Hz, 3H), 0.94 (d, J = 6.6, 3H), 1.21-1.40 (m, phenylsilane. The reaction flask was sealed, removed from 8H), 2.09-2.22 (m, 2H), 2.43-2.54 (m, lH), 4.51 and 4.53 (AB the glovebox, and placed in a magnetically stirred oil bath at system, JAB= 6.1 Hz, lJ29s1,~ = 194.3 Hz, 2H), 5.76 (d, J = 9.5 50 "C. After 12 h the reaction mixture was cooled to room Hz, lH), 7.32-7.40 (m, 3H), 7.55-7.57 (m, 2H); 13CNMR (100 temperature, diluted with 5 mL of hexanes, and filtered MHz, CDC13) 6 12.06, 13.98, 20.60, 22.46, 29.47,29.98,30.48, through a column of Florisil. The Florisil was rinsed two times 31.88, 34.65, 127.90, 129.43, 132.46, 132.85, 135.50, 152.27; with 5 mL portions of hexanes. The hexanes were combined IR (neat) 2131.0 cm-l; HRMS calcd for C17H28Si 260.1960, and concentrated by rotary evaporation. Crude material was found 260.1972; LRMS (EI) m / z (relative intensity) 260 (6.2), purified by flash chromatography in hexanes followed by 231 (6.6), 203 (291, 182 (361, 162 (271, 147 (201, 133 (18), 121 Kugelrohr distillation t o afford 83% (0.106 g, 0.43 mmol) of (35), 107 (loo),83 (57), 55 (31),41 (23). Anal. Calcd for C17H282a. Si: C, 78.38; H, 10.83. Found: C, 78.44; H, 10.96. (E)-5-(Phenylsilyl)-S-decene (2a). Purification by flash (E)-2,2-Dimethyl-4-(phenylsilyl)-3-tetradecene (2e). Puchromatography and Kugelrohr distillation afforded 83% of the rification by flash chromatography and Kugelrohr distillation desired product: oven temperature (ot) 85 "C/0.30 mmHg; Rf afforded 28% of the desired product ('99% pure by GC 0.49 (hexanes);lH NMR (400 MHz, CDC13) 6 0.84 (t,J = 6.97 analysis): ot 85-90 "U0.25 mmHg; Rf0.64 (hexanes); 'H NMR Hz, 3H), 0.90 (t,J = 6.97 Hz, 3H), 1.22-1.38 (m, 8H), 2.11(400 MHz, CDCl3) 6 0.87 (t, J = 6.8 Hz, 3H), 1.13(s,9H), 1.222 . 1 9 ( m , 4 H ) , 4 . 5 2 ( ~ , ~ J ~ ~ ~ ~ , ~ = 1 9 4 . 0 H z , 2 H ) , 6 . 0 0 ( t , J1.37 = 6 .(m, 9 1 16H), 2.28-2.31 (m, 2H), 4.49 (9,'JZgSi,H = 194.5 Hz, Hz, lH), 7.32-7.38 (m, 3H), 7.55-7.57 (m, 2H); 13CNMR (100 2H), 5.99 (s, lH), 7.31-7.39 (m, 3H), 7.54-7.56 (m, 2H); 13C MHz, CDC13) 6 13.92, 13.99, 22.46, 22.72, 28.53, 30.04, 31.53, NMR (100 MHz, CDC13) 6 14.11, 22.68, 29.32, 29.41, 29.55, 31.71,127.90, 129.44, 132.76,134.00, 135.54,146.23; IR (neat) 29.58,29.98, 30.06, 31.03, 31.10, 31.90,55.21, 127.89, 129.42, 133.05, 133.96, 135.48, 154.76; IR (neat) 2130 cm-'; HRMS (9) Typical alkylating procedure: 1.1equiv of alkyne in THF was calcd for C2zH3&i 330.2743, found 330.2739; LRMS (EI) m / z stirred at -78 "C. One equivalent of 1.6 M n-BuLi in hexanes was (relative intensity) 330 (lo), 315 (14), 287 (151, 273 (42), 189 added, and the mixture was stirred for 0.5 h, followed by the addition ( E ) , 175 (311,161 (391,121 (511,107 (100),97 (27),83 (34),69 of 1 equiv of the alkyl halide. The solution was warmed to room (23), 57 (58), 43 (47). Anal. Calcd for CzzH38Si: C, 79.92; H, temperature followed by an aqueous workup. HMPA was added when the alkylation involved a n alkyl halide other than Mel. 11.58. Found: C, 79.54; H, 11.77. (10) (a) Corey, E. J.; Venkatesvarlu, A. J . Am. Chem. SOC.1972, (E)-4-( (tert-Butyldimethylsilyl)oxy) -2-phenylsilyl-294,6190. (b) Corey, E. J.; Cho, H.; Riicker, C.; Hua, D. H. Tetrahedron pentene (4a). Purification by flash chromatography and Lett. 1981,22,3455. (c) Miyashita, M.; Yoshikoshi, A. J. Org. Chem. 1977, 42, 3772. (d) Colin-Messager, C.; Girard, J.-P.; Rossi, J.-C. Kugelrohr distillation afforded 82% of the desired product Tetrahedron Lett. 1992,33,2689. ('99% pure by GC analysis): ot 80-85 "C10.25 mmHg; Rf0.34 (11)Chen, C.; Senanayake, C. H.; Bill, T. J.; Larsen, R. D.; (7:l hexanes/dichloromethane); 'H NMR (400 MHz, CDC13) 6 Verhoeven, T. R.; Reider, P. J . Org. Chem. 1994,59,3738. 0.03 (9, 3H), 0.04 (9, 3H), 0.87 (5, 9H), 1.18 (d, J = 6.3 Hz, (12) (a) Threlkel, R. S.; Bercaw, J. E. J . Orgunomet. Chem. 1977, 136,l.(b) Den Haan, K. H.; Teuben, J. H. J . Organomet. Chem. 1987, 3H), 1.72 (d, J = 1.7 Hz, 3H), 4.49 (S, 'J%,H = 196.8 Hz, 2H), 322,321. (c) Den Haan, K. H.; Wielstra, Y.; Eshuis, J. J. W.; Teuben, 4.64-4.69 (m, lH), 6.01 (dq, J = 1.6, 7.6 Hz, lH), 7.33-7.41 J . H. J. Orgunomet. Chem. 1987,323,181. (m, 3H), 7.53-7.55 (m, 2H); 13C NMR (100 MHz, CDC13) 6 (13)Jeske, G.; Lauke, H.; Mauermann, H.; Swepston, P. N.; Schu-4.72, -4.58, 15.60, 18.23,23.76,25.86,65.67,126.73, 128.00, mann, H.; Marks, T. J. J . A m . Chem. SOC.1985,107, 8091.
Experimental Section
a
4574 Organometallics, Vol. 14,No.10,1995
Molander and Retsch
(E)-9-(Dimethylamino)-3-methyl-S-(phenylsilyl)-4-n0nene (6c). Purification by flash chromatography and Kugelrohr distillation afforded 73% of the desired product (>98% pure by GC analysis): ot 74-86 "C/0.16 mmHg; Rf 0.26 (ethyl acetate on triethylamine-deactivated silica); 'H NMR (400 MHz, CDC13) 6 0.84 (t, J = 7.4 Hz, 3H), 0.94 (d, J 6.6 Hz, 3H), 1.19-1.43 (m, 6H), 2.11-2.44 (m with overlapping s at 2.16, lOH), 2.44-2.52 (m, lH), 4.51 and 4.53 (AB system, JAB = 5.9 Hz, ' J z ~ s i ,=~ 194.8 Hz, 2H), 5.76 (d, J = 4.9 Hz, lH), 7.31-7.39 (m, 3H), 7.54-7.56 (m, 2H); 13C NMR (100 MHz, CDCl3) 6 12.04,20.55,27.62,27.83,29.91,30.40,34.62, 45.48, 59.73,127.90, 129.44,132.07, 132.67, 135.46, 152.50; IR (neat) 2130.4 cm-'; HRMS calcd for C18H31NSi 289.2226 (M - HI+, found 289.2226; LRMS (EI) m / z (relative intensity) 289 (7.5), 274 (35)) 232 (31), 182 (301, 107 (211, 105 (141, 58 (1001, 45 (16), 44 (12), 42 (13), 30 (7.5),29 (7.1). Anal. Calcd for C18H31NSi: C, 74.67; H, 10.79. Found: C, 74.63; H, 10.60. (9E)-(6R,1lR,S)-2,6,1 l-Trimethyl-9-(phenylsilyl)-2,9tridecadiene (8). Purification by preparative thin-layer chromatography and heating under high vacuum at 60 "C for 3 h afforded 80% of the desired product (>99% pure by GC analysis): Rf0.21 (hexanes); 'H NMR (400 MHz, CDCb) 6 0.83 (t, J = 6.7 Hz, 3H), 0.85 (t, J = 7.4 Hz, 3H), 0.95 (d, J = 6.6 Hz, 3H), 1.04-1.40 (m, 7H), 1.58 (s, 3H), 1.67 (s, 3H), 1.831.95 (m, 2H), 2.06-2.24 (m, 2H), 2.43-2.54 (m, lH), 4.52 and 4.54 (AB system, JAB= 7.0 Hz, 'J29s1,H = 194.6 Hz, 2H), 5.07 (t, J = 6.9 Hz, lH), 5.75 (d, J = 9.6 Hz, lH), 7.32-7.40 (m, 3H), 7.55-7.58 (m, 2H); 13CNMR (100 MHz, CDC13) 6 12.11, 17.62, 19.41, 19.50, 20.66, 25.50, 25.73, 27.93, 29.97, 32.53, 32.56, 34.67, 36.80, 36.88, 36.96, 124.94, 127.90, 129.44, 130.99, 132.53, 132.78, 135.51, 152.06; IR (neat) 2130.7 cm-'; HRMS calcd for C22H36Si 328.2586, found 328.2576; LRMS (EI) m l z (relative intensity) 328 (1.4),299 (141, 189 (17), 161 (29), 121 (50), 107 (1001, 105 (43), 81 (38), 69 (go), 57 (11),43(141, 29 (18). Anal. Calcd for C22H36Si: C, 80.41; H, 11.04. Found: C, 80.35; H, 11.05. (E)-2-(Phenylsilyl)-2-nonene (loa) and (E)3-(Phenylsilyl)-2-nonene (lob). The product ratio in the crude reaction (E)-9-Chloro-3-methyl-S-(phenylsilyl)4nonene (6a). Pumixture was 4.1:l by GC analysis. The major product was rification by flash chromatography and Kugelrohr distillation determined by the integration and splitting pattern of the afforded 79% of the desired product (98% pure by GC analyolefinic resonances in the 'H NMR. The products were sis): ot 60-70 "C/O.19 mmHg; RfO.25 (hexanes); 'H NMR (400 inseparable by TLC and HPLC. Purification by preparative MHz, CDC13) 6 0.85 (t, J = 7.4 Hz, 3H), 0.95 (d, J = 6.6 Hz, thin-layer chromatography and Kugelrohr distillation afforded 3H), 1.19-1.28 (m, lH), 1.30-1.40 (m, lH), 1.41-1.52 (m, 2H), an 81%yield of the product mixture (>98% overall purity by 1.65-1.74 (m, 2H), 2.12-2.25 (m, 2H), 2.42-2.53 (m, lH), 3.44 GC analysis): ot 50-58 "(30.23 mmHg; Rf 0.68 (hexanes);'H (t, J = 6.7 Hz, 2H), 4.52 and 4.54 (AB system, JAB= 7.3 Hz, NMR (400 MHz, CDC13) 6 0.83-0.90 (m, 3H), 1.22-1.40 (m, 'J29S1,H = 195.5 Hz, 2H), 5.80 (d, J = 9.6 Hz, lH), 7.33-7.41 8H), 1.71-1.73 (m, 3H), 2.10-2.20 (m, 2H), 4.50 (5, 'J29S1,H = (m, 3H), 7.55-7.57 (m, 2H); 13C NMR (100 MHz, CDC13) 6 194.9 Hz, 1.6H),4.51 (S, 'J29s1,H = 194.5 Hz, 0.4H), 6.04 (td, J 12.06, 20.57, 26.90, 29.58, 29.90, 32.43, 34.72, 44.78, 127.97, =6.9, 1.6Hz,0.8H),6.09(q,J=6.5Hz,0.2H),7.33-7.41(m, 129.56, 131.57, 132.45, 135.46, 152.96; IR (neat) 2131.3 cm-'; 3H), 7.54-7.60 (m, 2H); 13CNMR (100 MHz, CDC13) 6 14.08, HRMS calcd for C1.&sSiC1 279.1336 (M - HI+,found 279.1325; 14.64, 15.47, 22.60, 22.63, 28.87, 28.99, 29.05, 29.13, 29.28, LRMS (EI) m l z (relative intensity) 279 (30), 223 (27), 173 (391, 29.94, 31.68, 31.74, 127.92, 127.94, 128.46, 129.47, 129.52, 141 (97), 109 (loo), 107 (831, 81 (go), 69 (551, 55 (681, 43 (14). 132.32, 132.67, 135.35, 135.48, 135.56, 139.89, 146.29; IR Anal. Calcd for C16H25SiC1: C, 68.41; H, 8.97. Found: C, (neat) 2130.5 cm-'; HRMS calcd for C15H24Si 232.1647, found 68.01; H, 8.76. (E)-3-Methyl-S-(phenylsilyl)-9-((tetrahydrop~anyl)-232.1639; LRMS (E11 m/z (relative intensity) 232 (5.31, 203 (5.8), 147 (24), 121 (391, 107 (loo), 105 (801, 81 (26), 43 (27), oxy)4-nonene (6b). Purification by flash chromatography 29 (31). Anal. Calcd for C15H24Si: C, 77.51; H, 10.41. and heating under high vacuum afforded 84% of the desired Found: C , 77.50; H, 10.57. product (299% pure by GC analysis): Rf0.30(7%ethyl acetate (E)-S-Methyl-2-(phenylsilyl)-2-heptene (12a) and (E)in hexanes); 'H NMR (400 MHz, CDCl3) 6 0.85 (t, J = 7.4 Hz, S-Methyl-3-(phenylsilyl)-2-heptene (12b). The product 3H), 0.94 (d, J = 6.6 Hz, 3H), 1.18-1.60 (m, lOH), 1.63-1.71 ratio in the crude reaction mixture was 7.3:l by GC analysis. (m, lH), 1.75-1.83 (m, lH), 2.13-2.27 (m, 2H), 2.44-2.53 (m, The major product was determined by the integration and lH), 3.31 (dt, J = 6.4, 9.6 Hz, lH), 3.44-3.49 (m, lH), 3.67 splitting pattern of the olefinic resonances in the 'H NMR. (dt, J = 6.6, 9.6 Hz, lH), 3.79-3.85 (m, lH), 4.51-4.54 (m, The products were inseparable by TLC. Purification by flash 'Jzgs1,H = 194.6 Hz, 3H), 5.78 (d, J = 9.6 Hz, lH), 7.31-7.40 chromatography and Kugelrohr distillation afforded a 40% (m, 3H), 7.54-7.56 (m, 2H); 13C NMR (100 MHz, CDC13) 6 yield of the product mixture ('97% overall purity by GC 12.04, 19.52, 20.57, 25.49, 26.45, 29.69, 29.91, 30.26, 30.70, analysis): ot 58-62 "U0.28 mmHg; Rf0.53 (hexanes); 'H NMR 34.64, 62.10, 67.21, 98.64, 127.90, 129.44, 132.09, 132.65, (400 MHz, CDC13) 6 0.79-0.89 (m, 6H), 1.10-1.19 (m, lH), 135.45, 152.57; IR (neat) 2130.4 cm-'; HRMS calcd for 1.31-1.47(m,2H), 1.70-1.72(m,3H), 1.94-2.01(m,1H),2.09C21H3402Si 345.2250 (M - HI+, found 345.2241; LRMS (EI) 2.16 (m, lH), 4.50 (s, 'J29S1,H = 194.8 Hz, 2H), 6.05 (td, J = m l z (relative intensity) 346 (0.241, 261 (4.0), 232 (6.51, 203 7.0, 1.6 Hz, 0.88H), 6.15 (9, J = 6.4 Hz, 0.12H), 7.33-7.38 (m, (7.0), 177 (6.71, 123 (391, 107 (321, 85 (100),67 (201, 55 (20),41 NMR (100 MHz, CDC13) 6 11.56, 3H), 7.54-7.56 (m, 2H); (31).
129.66, 131.63, 135.50, 150.40; IR (neat) 2133 cm-l; HRMS calcd for C17H300Si2 306.1835, found 306.1823; LRMS (EI)mlz (relative intensity) 306 (3), 249 (37), 207 (lo), 193 (25), 181 (loo), 171 (12), 145 (111, 135 (131, 121 (161, 107 (21), 75 (581, 57 (11),41 (7). Anal. Calcd for C17H300Si2: C, 66.60; H, 9.86. Found: C, 66.39; H, 9.84. (E)-%((tert-Butyldimethylsilyl)oxy)-4-(phenylsilyl)-3tetradecene (4b). Purification by flash chromatography and Kugelrohr distillation afforded 84% of the desired product ('99% pure by GC analysis): ot 100-120 "ClO.25 mmHg; Rf 0.36 (7% dichloromethane in hexanes); 'H NMR (400 MHz, CDC13) 6 0.02 (s, 3H), 0.03 (s, 3H), 0.86 ( 8 , 9H), 0.87 (t,J = 6.9 Hz, 3H), 1.17-1.36 (m, 19H),2.07-2.21 (m, 2H), 4.49 and 4.50 (AB system, JAB= 6.3 Hz, 'J29sl,H = 196.4 Hz, 2H), 4.68 (dq, J = 6.4, 7.5 Hz, lH), 5.98 (d, J = 7.8 Hz, lH), 7.31-7.40 (m, 3H), 7.53-7.55 (m, 2H); 13C NMR (100 MHz, CDCl3) 6 -4.61, -4.46, 14.11, 18.21, 22.69, 24.46, 25.87, 29.32, 29.39, 29.52, 29.55, 29.59,29.74,30.77, 31.91,65.48, 127.96, 129.59, 132.12, 132.35, 135.56, 150.31; IR (neat) 2134.1 cm-'; HRMS calcd for C26H480Si2 432.3244, found 432.3243; LRMS (EI) m lz (relative intensity) 432 (2.2), 375 (39), 300 (6.3),181(loo), 121 (13), 107 (241, 75 (501, 57 (9), 41 (13). ( E ) -1-((tert-Butyldimethylsilyl)oxy)-3-phenylsilyl-2butene (4c). Purification by preparative thin-layer chromatography and Kugelrohr distillation afforded 23% of the desired product (>99% pure by GC analysis): ot 78-82 "Cl 0.10 mmHg; Rf 0.60 (2:l hexanesldichloromethane); lH NMR (400 MHz, CDC13) 6 0.06 (s, 6H), 0.89 (s, 9H), 1.71 (9, 3H), 4.30 (d, J = 5.2 Hz, 2H), 4.50 (9, 'J29S1,H = 197.0 Hz, 2H), 6.10 (tq, J = 1.7, 5.3 Hz, lH), 7.32-7.41 (m, 3H), 7.54-7.56 (m, 2H); '3C NMR (100 MHz, CDC13) 6 -5.15, 15.82, 18.37,25.94, 60.69,100.90, 128.00,129.53, 129.70,131.57, 145.27; IR (neat) 2133 cm-'; HRMS calcd for C16H2sOSiz 292.1679, found 292.1690; LRMS (EI) mlz (relative intensity) 292 (12), 235 (41), 233 (20), 207 (121, 193 (381, 181(1001, 179 (631, 157 (191, 135 (19), 121 (13),107 (211, 105 (27), 75 (771, 73 (42),59 (14), 57 (12), 41 (10).
Hydrosilylation Catalyzed by Cp Y;YCHyTHF 15.63, 19.13, 19.23, 29.34, 29.53, 34.66, 34.85, 35.78, 37.16, 127.91,127.96,129.19, 129.47,129.52, 132.34,135.47,135.58, 140.69,145.10; IR (neat) 2130.3 cm-'; HRMS calcd for C14H22Si 218.1491, found 218.1497; LRMS (EI) m / z (relative intensity) 218 (13), 203 (5.6)) 161 (33))147 (431, 134 (43), 121 (601, 107 (loo), 105 (741, 84 (22), 57 (241, 43 (181, 41 (291, 29 (31). (E)-3-Methyl-6-(phenylsilyl)-S-decene (14a)and (E)-3Methyl-6-(phenylsilyl)-6-decene(14b). The product ratio in the crude reaction mixture was 1:l by GC analysis. The products were inseparable by TLC and HPLC. Purification by flash chromatography and Kugelrohr distillation afforded 73% of the product mixture (>99% overall purity by GC mmHg; RfO.55(hexanes); 'H NMR analysis): ot 84-98 "C/0.28 (400 MHz, CDCL) 6 0.78-0.92 (m, 9H), 1.01-1.52 (m, 7H), 1.94-2.04 (m, lH), 2.11-2.19 (m, 3H), 4.50-4.54 (m, ' J z ~ s i = ,~ 194.5 Hz, 2H), 6.00-6.07 (m, lH), 7.33-7.41 (m, 3H), 7.557.68 (m, 2H); 13CNMR (100 MHz, CDC13) 6 11.54,11.56,13.94, 14.00, 19.18, 19.26, 22.48, 22.75, 28.83, 29.37, 29.53, 30.14, 31.48,31.63,34.63,34.96,35.69,37.60,127.90, 129.43,132.75, 132.78, 133.24, 134.71, 135.52, 135.54, 145.11, 147.07; IR (neat) 2130.3 cm-'; HRMS calcd for C1&& 260.1960, found 260.1962; LRMS (EI) m l z (relative intensity) 260 (7.51, 203 (12), 161 (19), 147 (20), 121 (241, 107 (loo), 105 (501, 97 (191, 81 (ll),55 (171, 29 (16). Anal. Calcd for C~d-bSi: C, 78.38; H, 10.83. Found: C, 78.30; H, 10.72. (E)-3-(Triphenylmethoxy)-&(phenylsily1)-6-decene (16a) and (E)-3-(Triphenylmethoxy)-6-(phenylsilyl)-5-decene (16b). The product ratio in the crude reaction mixture was
Organometallics, Vol. 14, No. 10, 1995 4575 2.5:l by 'H NMR. The major product was determined by the diastereotopic protons on silicon in the 'H NMR. The products were inseparable by TLC. Purification by flash chromatography and heating at 100 "C for 3 h at 0.12 mmHg afforded 64% of the product mixture (>95% overall purity by GC analysis): Rf 0.55 (hexanes); 'H NMR (400 MHz, CDC13) 6 0.63-0.72 (m, 3H), 0.79-0.89 (m, 3H), 1.01-1.31 (m, 6H), 2.02-2.27 (m, 3.75H), 2.57 (dd, J =15.0,g.O Hz, 0.25H), 3.383.43 (m, 0.71H), 3.52-3.57 (m,0.29H), 4.29 and 4.31 (AB system, JAB = 6.4 Hz, 'Jzssi,, = 199.2 Hz, 0.57H), 4.48 (s, 1J29S1,H = 194.8 Hz, 1.43H), 5.88 (t, J = 6.6 Hz, 0.71H), 5.95 (t, J = 6.6 Hz, 0.29H), 7.21-7.51 (m, 20H); 13CNMR (100 MHz, CD2Clz) 6 8.59,9.27, 14.07,14.14,22.80,23.09,25.46,27.08,29.41, 30.69, 31.71, 31.85, 33.13, 35.91, 73.86, 74.68, 86.83, 127.15, 129.76, 127.23, 127.93, 127.97,128.22,128.26,129.30,129.35, 129.84, 131.26, 132.88,135.76, 135.80, 135.88,142.64, 145.93, 148.88; IR (neat) 2129.9 cm-'; HRMS calcd for C3bH400Si 503.2770 (M - H)+,found 503.2769; LRMS (EI) m / z (relative intensity) 503 (0.34), 243 (1001, 165 (681, 107 (361, 105 (391, 91 (8.6), 77 (15), 41 (8.Q 29 (8.0). Anal. Calcd for c35H40OSi: C, 83.28; H, 7.99. Found: C, 83.01, H, 7.77.
Acknowledgment. We wish to thank the National Institutes of Health for their generous support of this research. OM950311W
