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ISSN: 2056-9890

Triphen­yl(prop-2-yn-1-yl)silane

aFakultät Chemie, Technische Universität Dortmund, Otto-Hahn-Strasse 6, 44221 Dortmund, Germany
*Correspondence e-mail: hans.preut@tu-dortmund.de

(Received 4 January 2012; accepted 10 January 2012; online 18 January 2012)

In the title compound, C21H18Si, the coordination geometry around the Si atom is a slightly distorted tetra­hedron with C—Si—C angles in the range 106.05 (11) to 110.58 (10) ° and Si–C bond lengths in the range 1.855 (2) to 1.883 (3) Å. The alkyne C—C bond length is 1.167 (4) Å. The dihedral angles between the three phenyl rings are 63.89 (7), 86.38 (7) and 70.51 (8)°. In the crystal, mol­ecules inter­act only by van der Waals forces.

Related literature

For the first report of the title compound, see: Masson et al. (1967[Masson, J. C., Le Quan, M. & Cadiot, P. (1967). Bull. Soc. Chim. Fr. pp. 777-777.]). For background to silane chemistry, see: Abraham et al. (2001[Abraham, L., Czerwonka, R. & Hiersemann, M. (2001). Angew. Chem. Int. Ed. 40, 4700-4703.], 2003[Abraham, L., Pollex, A. & Hiersemann, M. (2003). Synlett, pp. 1088-1095.]); Helmboldt & Hiersemann (2003[Helmboldt, H. & Hiersemann, M. (2003). Tetrahedron, 59, 4031-4038.]); Hiersemann (1999[Hiersemann, M. (1999). Tetrahedron, 55, 2625-2638.], 2000[Hiersemann, M. (2000). Synthesis, pp. 1279-1290.]); Nelson et al. (2011[Nelson, B., Hiller, W., Pollex, A. & Hiersemann, M. (2011). Org. Lett. 13, 4438-4441.]).

[Scheme 1]

Experimental

Crystal data
  • C21H18Si

  • Mr = 298.44

  • Triclinic, [P \overline 1]

  • a = 9.6668 (11) Å

  • b = 9.6857 (7) Å

  • c = 10.1178 (10) Å

  • α = 80.289 (7)°

  • β = 65.189 (10)°

  • γ = 72.957 (8)°

  • V = 820.98 (16) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 0.14 mm−1

  • T = 173 K

  • 0.40 × 0.30 × 0.10 mm

Data collection
  • Oxford Diffraction Xcalibur S CCD diffractometer

  • Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2008[Oxford Diffraction (2008). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Yarnton, England.]) Tmin = 0.973, Tmax = 0.986

  • 8081 measured reflections

  • 3224 independent reflections

  • 1940 reflections with I > 2σ(I)

  • Rint = 0.048

Refinement
  • R[F2 > 2σ(F2)] = 0.048

  • wR(F2) = 0.086

  • S = 1.05

  • 3224 reflections

  • 211 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.34 e Å−3

  • Δρmin = −0.29 e Å−3

Data collection: CrysAlis CCD (Oxford Diffraction, 2008[Oxford Diffraction (2008). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Yarnton, England.]); cell refinement: CrysAlis CCD; data reduction: CrysAlis RED (Oxford Diffraction, 2008[Oxford Diffraction (2008). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Yarnton, England.]); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL-Plus (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

Supporting information


Comment top

The title compound (I) (Masson et al., 1967) was synthesized from 3-bromoprop-1-yne by Grignard-reaction with ClSiPh3. Silane acts as an intermediate en route to alkoxy-carbonyl substituted allyl vinyl ethers (Hiersemann, 2000), which exhibit a wide range of reactivity for further synthetic transformation (Hiersemann, 1999; Abraham et al., 2001; Abraham et al., 2003; Helmboldt et al., 2003; Nelson et al., 2011) developed in our laboratory.

Related literature top

For the first report of the title compound, see: Masson et al. (1967). For background to silane chemistry, see: Abraham et al. (2001, 2003); Helmboldt & Hiersemann (2003); Hiersemann (1999, 2000); Nelson et al. (2011).

Experimental top

To an oven dried, three-necked-flask (equipped with a reflux condenser, a dropping funnel and a stopper, which is ultimately switched with a thermometer) under an atmosphere of argon was added Mg powder (1.02 g, 42 mmol, 2.1 eq) and HgCl2 (0.36 g, 1.3 mmol, 0.06 eq). The flask was heated with a heatgun, sealed with a septum and allowed to cool down to room temperature under an atmosphere of argon before Et2O (14 ml, 0.33 ml/mmol Mg) was added carefully. The flask was cooled to 273 K and propargylbromide (4.3 ml, 40 mmol, 2 eq, 80% in toluene) in Et2O (14 ml, 0.35 ml/mmol bromide) was added dropwise over a period of 25 min. After addition of the first few drops the solution became cloudy and started to boil. The rate of the addition was adjusted to maintain the internal temperature between 273 K and 293 K. The dark solution was stirred further for 50 min at 273 K before chlorotriphenylsilane (5.9 g, 20 mmol, 1 eq) in Et2O (50 ml, 2.5 ml/mmol silane) was added dropwise over a period of 30 min. The resulting reaction mixture was allowed to warm to room temperature overnight (16 h) and was then diluted by the careful addition of saturated aqueous NH4Cl solution and n-pentane. The aqueous layer was extracted with n-pentane (3 × and the combined organic phases were dried (MgSO4) and concentrated under reduced pressure (greater than 5 mbar). Purification by flash chromatography (n-pentane/Et2O 100/1) afforded silane I (2.3 g, 7.7 mmol, 38%) as a white solid. Subsequent recrystallization of I by vapor diffusion technique from isohexane and ethyl acetate provided colourless plates of (I). Rf 0.34 (cyclohexane/ethyl acetate 20/1); 1H NMR (CDCl3, 400 MHz, δ): 1.87 (t, J = 2.9 Hz, 1H), 2.35 (d, J = 3.0 Hz, 2H), 7.38–7.48 (m, 9H), 7.59–7.60 (m, 6H); C21H18Si, M = 298.45 g/mol.

Refinement top

The hydrogen atoms of the phenyl rings were placed in calculated positions with C–H bond distances of 0.95Å and refined as riding on their parent atoms with Uiso = 1.2 x Ueq(C). For the remaining hydrogen atoms coordinates and an isotropic temperature factor were refined.

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2008); cell refinement: CrysAlis CCD (Oxford Diffraction, 2008); data reduction: CrysAlis RED (Oxford Diffraction, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL-Plus (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. : The molecular structure of the title compound, showing displacement ellipsoids at the 30% probability level.
Triphenyl(prop-2-yn-1-yl)silane top
Crystal data top
C21H18SiZ = 2
Mr = 298.44F(000) = 316
Triclinic, P1Dx = 1.207 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 9.6668 (11) ÅCell parameters from 2879 reflections
b = 9.6857 (7) Åθ = 2.2–29.1°
c = 10.1178 (10) ŵ = 0.14 mm1
α = 80.289 (7)°T = 173 K
β = 65.189 (10)°Plate, colourless
γ = 72.957 (8)°0.40 × 0.30 × 0.10 mm
V = 820.98 (16) Å3
Data collection top
Oxford Diffraction Xcalibur S CCD
diffractometer
3224 independent reflections
Radiation source: Enhance (Mo) X-ray Source1940 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.048
Detector resolution: 16.0560 pixels mm-1θmax = 26.0°, θmin = 2.2°
ω scansh = 1111
Absorption correction: multi-scan
(CrysAlis RED; Oxford Diffraction, 2008)
k = 1111
Tmin = 0.973, Tmax = 0.986l = 1212
8081 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.048Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.086H atoms treated by a mixture of independent and constrained refinement
S = 1.05 w = 1/[σ2(Fo2) + (0.0228P)2]
where P = (Fo2 + 2Fc2)/3
3224 reflections(Δ/σ)max < 0.001
211 parametersΔρmax = 0.34 e Å3
0 restraintsΔρmin = 0.29 e Å3
Crystal data top
C21H18Siγ = 72.957 (8)°
Mr = 298.44V = 820.98 (16) Å3
Triclinic, P1Z = 2
a = 9.6668 (11) ÅMo Kα radiation
b = 9.6857 (7) ŵ = 0.14 mm1
c = 10.1178 (10) ÅT = 173 K
α = 80.289 (7)°0.40 × 0.30 × 0.10 mm
β = 65.189 (10)°
Data collection top
Oxford Diffraction Xcalibur S CCD
diffractometer
3224 independent reflections
Absorption correction: multi-scan
(CrysAlis RED; Oxford Diffraction, 2008)
1940 reflections with I > 2σ(I)
Tmin = 0.973, Tmax = 0.986Rint = 0.048
8081 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0480 restraints
wR(F2) = 0.086H atoms treated by a mixture of independent and constrained refinement
S = 1.05Δρmax = 0.34 e Å3
3224 reflectionsΔρmin = 0.29 e Å3
211 parameters
Special details top

Experimental. Absorption correction: CrysAlis RED, Oxford Diffraction Ltd., Version 1.171.32.37 (release 24-10-2008) Empirical absorption correction using sperical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C10.8154 (3)0.5812 (3)0.1515 (4)0.0418 (7)
C20.7846 (3)0.6191 (2)0.2662 (3)0.0332 (6)
C30.7508 (3)0.6647 (3)0.4086 (3)0.0395 (7)
C40.7985 (2)0.9730 (2)0.3179 (2)0.0257 (6)
C50.8267 (2)0.9789 (2)0.1710 (2)0.0328 (6)
H50.87350.89200.12050.039*
C60.7884 (3)1.1085 (2)0.0958 (3)0.0368 (6)
H60.80731.11010.00440.044*
C70.7222 (3)1.2353 (2)0.1697 (3)0.0382 (7)
H70.69581.32460.11950.046*
C80.6944 (2)1.2329 (2)0.3138 (3)0.0378 (7)
H80.64931.32060.36310.045*
C90.7317 (2)1.1033 (2)0.3891 (3)0.0308 (6)
H90.71181.10280.48940.037*
C100.8073 (2)0.8192 (2)0.6057 (2)0.0256 (5)
C110.6509 (2)0.8669 (2)0.7011 (2)0.0286 (6)
H110.57120.89320.66350.034*
C120.6081 (3)0.8771 (2)0.8479 (3)0.0297 (6)
H120.50030.90820.91020.036*
C130.7231 (3)0.8417 (2)0.9041 (3)0.0314 (6)
H130.69490.84941.00500.038*
C140.8787 (3)0.7953 (2)0.8126 (2)0.0301 (6)
H140.95780.77080.85090.036*
C150.9206 (2)0.7841 (2)0.6660 (2)0.0285 (6)
H151.02850.75200.60460.034*
C161.0757 (2)0.7216 (2)0.3174 (2)0.0247 (5)
C171.1798 (3)0.8035 (2)0.2971 (2)0.0313 (6)
H171.13860.90000.32750.038*
C181.3405 (3)0.7505 (2)0.2347 (3)0.0364 (6)
H181.40860.80870.22460.044*
C191.4016 (3)0.6110 (2)0.1867 (3)0.0417 (7)
H191.51230.57350.14180.050*
C201.3025 (3)0.5280 (2)0.2043 (3)0.0439 (7)
H201.34490.43250.17120.053*
C211.1409 (3)0.5807 (2)0.2696 (2)0.0337 (6)
H211.07380.52070.28200.040*
H10.764 (3)0.588 (2)0.475 (3)0.053 (8)*
H20.646 (3)0.707 (2)0.454 (3)0.049 (8)*
H30.839 (2)0.557 (2)0.066 (2)0.030 (7)*
Si0.85982 (7)0.79610 (6)0.41079 (7)0.02875 (19)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0559 (19)0.0359 (16)0.042 (2)0.0082 (13)0.0273 (18)0.0081 (14)
C20.0379 (15)0.0241 (13)0.0428 (18)0.0094 (11)0.0203 (14)0.0002 (12)
C30.0437 (18)0.0345 (16)0.042 (2)0.0121 (13)0.0166 (16)0.0017 (14)
C40.0234 (13)0.0262 (12)0.0294 (15)0.0051 (10)0.0131 (12)0.0010 (11)
C50.0318 (14)0.0298 (13)0.0381 (17)0.0064 (11)0.0155 (13)0.0025 (12)
C60.0373 (15)0.0431 (15)0.0328 (16)0.0103 (12)0.0193 (13)0.0060 (13)
C70.0341 (15)0.0307 (14)0.0495 (19)0.0038 (11)0.0221 (14)0.0065 (13)
C80.0314 (14)0.0225 (13)0.0586 (19)0.0033 (10)0.0188 (14)0.0031 (13)
C90.0296 (13)0.0282 (13)0.0349 (16)0.0050 (10)0.0127 (12)0.0063 (11)
C100.0317 (13)0.0150 (11)0.0314 (14)0.0049 (10)0.0148 (12)0.0008 (10)
C110.0287 (14)0.0243 (13)0.0360 (16)0.0046 (10)0.0175 (13)0.0004 (11)
C120.0279 (13)0.0227 (12)0.0366 (16)0.0030 (10)0.0118 (12)0.0046 (11)
C130.0400 (15)0.0281 (13)0.0281 (15)0.0059 (11)0.0156 (13)0.0050 (11)
C140.0344 (15)0.0265 (13)0.0333 (16)0.0044 (11)0.0195 (13)0.0008 (11)
C150.0277 (13)0.0214 (12)0.0345 (16)0.0028 (10)0.0126 (12)0.0018 (11)
C160.0330 (14)0.0165 (11)0.0244 (14)0.0034 (10)0.0139 (12)0.0017 (10)
C170.0359 (15)0.0203 (12)0.0355 (16)0.0002 (11)0.0153 (13)0.0048 (11)
C180.0364 (15)0.0315 (14)0.0398 (17)0.0081 (11)0.0144 (13)0.0003 (12)
C190.0339 (15)0.0321 (15)0.0471 (19)0.0036 (12)0.0117 (14)0.0038 (13)
C200.0463 (17)0.0218 (13)0.0550 (19)0.0059 (12)0.0190 (15)0.0086 (12)
C210.0415 (15)0.0189 (12)0.0422 (17)0.0070 (11)0.0187 (14)0.0002 (11)
Si0.0332 (4)0.0224 (3)0.0325 (4)0.0035 (3)0.0166 (3)0.0020 (3)
Geometric parameters (Å, º) top
C1—C21.167 (4)C11—C121.377 (3)
C1—H30.85 (2)C11—H110.9500
C2—C31.453 (4)C12—C131.386 (3)
C3—Si1.883 (3)C12—H120.9500
C3—H10.93 (2)C13—C141.377 (3)
C3—H20.92 (2)C13—H130.9500
C4—C51.388 (3)C14—C151.379 (3)
C4—C91.402 (3)C14—H140.9500
C4—Si1.871 (2)C15—H150.9500
C5—C61.390 (3)C16—C171.387 (3)
C5—H50.9500C16—C211.399 (3)
C6—C71.387 (3)C16—Si1.860 (2)
C6—H60.9500C17—C181.376 (3)
C7—C81.366 (3)C17—H170.9500
C7—H70.9500C18—C191.387 (3)
C8—C91.388 (3)C18—H180.9500
C8—H80.9500C19—C201.363 (3)
C9—H90.9500C19—H190.9500
C10—C111.396 (3)C20—C211.385 (3)
C10—C151.399 (3)C20—H200.9500
C10—Si1.855 (2)C21—H210.9500
C2—C1—H3177.5 (15)C13—C12—H12120.2
C1—C2—C3178.4 (3)C14—C13—C12119.5 (2)
C2—C3—Si116.24 (19)C14—C13—H13120.2
C2—C3—H1113.5 (15)C12—C13—H13120.2
Si—C3—H1107.8 (14)C13—C14—C15120.6 (2)
C2—C3—H2110.3 (15)C13—C14—H14119.7
Si—C3—H2106.5 (14)C15—C14—H14119.7
H1—C3—H2101 (2)C14—C15—C10121.3 (2)
C5—C4—C9117.8 (2)C14—C15—H15119.3
C5—C4—Si119.61 (16)C10—C15—H15119.3
C9—C4—Si122.45 (18)C17—C16—C21117.0 (2)
C4—C5—C6121.8 (2)C17—C16—Si120.64 (16)
C4—C5—H5119.1C21—C16—Si122.34 (17)
C6—C5—H5119.1C18—C17—C16122.6 (2)
C7—C6—C5118.8 (2)C18—C17—H17118.7
C7—C6—H6120.6C16—C17—H17118.7
C5—C6—H6120.6C17—C18—C19119.1 (2)
C8—C7—C6120.6 (2)C17—C18—H18120.5
C8—C7—H7119.7C19—C18—H18120.5
C6—C7—H7119.7C20—C19—C18119.8 (2)
C7—C8—C9120.5 (2)C20—C19—H19120.1
C7—C8—H8119.8C18—C19—H19120.1
C9—C8—H8119.8C19—C20—C21121.0 (2)
C8—C9—C4120.4 (2)C19—C20—H20119.5
C8—C9—H9119.8C21—C20—H20119.5
C4—C9—H9119.8C20—C21—C16120.5 (2)
C11—C10—C15116.7 (2)C20—C21—H21119.7
C11—C10—Si121.16 (16)C16—C21—H21119.7
C15—C10—Si122.11 (17)C10—Si—C16110.12 (10)
C12—C11—C10122.3 (2)C10—Si—C4110.58 (10)
C12—C11—H11118.8C16—Si—C4109.44 (9)
C10—C11—H11118.8C10—Si—C3106.05 (11)
C11—C12—C13119.6 (2)C16—Si—C3110.24 (12)
C11—C12—H12120.2C4—Si—C3110.37 (11)
C9—C4—C5—C61.0 (3)Si—C16—C21—C20178.13 (17)
Si—C4—C5—C6177.71 (16)C11—C10—Si—C16176.80 (16)
C4—C5—C6—C70.9 (3)C15—C10—Si—C160.4 (2)
C5—C6—C7—C80.3 (4)C11—C10—Si—C462.13 (19)
C6—C7—C8—C90.2 (4)C15—C10—Si—C4120.69 (17)
C7—C8—C9—C40.1 (3)C11—C10—Si—C357.54 (19)
C5—C4—C9—C80.5 (3)C15—C10—Si—C3119.65 (19)
Si—C4—C9—C8177.12 (16)C17—C16—Si—C1067.59 (18)
C15—C10—C11—C121.1 (3)C21—C16—Si—C10110.05 (19)
Si—C10—C11—C12176.23 (17)C17—C16—Si—C454.2 (2)
C10—C11—C12—C131.2 (3)C21—C16—Si—C4128.19 (19)
C11—C12—C13—C140.7 (3)C17—C16—Si—C3175.74 (17)
C12—C13—C14—C150.1 (3)C21—C16—Si—C36.6 (2)
C13—C14—C15—C100.0 (3)C5—C4—Si—C10179.73 (17)
C11—C10—C15—C140.5 (3)C9—C4—Si—C103.7 (2)
Si—C10—C15—C14176.79 (16)C5—C4—Si—C1658.8 (2)
C21—C16—C17—C180.8 (3)C9—C4—Si—C16117.74 (18)
Si—C16—C17—C18176.96 (17)C5—C4—Si—C362.7 (2)
C16—C17—C18—C191.6 (4)C9—C4—Si—C3120.76 (19)
C17—C18—C19—C201.2 (4)C2—C3—Si—C10174.65 (19)
C18—C19—C20—C210.0 (4)C2—C3—Si—C1655.5 (2)
C19—C20—C21—C160.8 (4)C2—C3—Si—C465.6 (2)
C17—C16—C21—C200.4 (3)

Experimental details

Crystal data
Chemical formulaC21H18Si
Mr298.44
Crystal system, space groupTriclinic, P1
Temperature (K)173
a, b, c (Å)9.6668 (11), 9.6857 (7), 10.1178 (10)
α, β, γ (°)80.289 (7), 65.189 (10), 72.957 (8)
V3)820.98 (16)
Z2
Radiation typeMo Kα
µ (mm1)0.14
Crystal size (mm)0.40 × 0.30 × 0.10
Data collection
DiffractometerOxford Diffraction Xcalibur S CCD
diffractometer
Absorption correctionMulti-scan
(CrysAlis RED; Oxford Diffraction, 2008)
Tmin, Tmax0.973, 0.986
No. of measured, independent and
observed [I > 2σ(I)] reflections
8081, 3224, 1940
Rint0.048
(sin θ/λ)max1)0.617
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.048, 0.086, 1.05
No. of reflections3224
No. of parameters211
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.34, 0.29

Computer programs: CrysAlis CCD (Oxford Diffraction, 2008), CrysAlis RED (Oxford Diffraction, 2008), SHELXS97 (Sheldrick, 2008), SHELXTL-Plus (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

 

References

First citationAbraham, L., Czerwonka, R. & Hiersemann, M. (2001). Angew. Chem. Int. Ed. 40, 4700–4703.  Web of Science CrossRef CAS Google Scholar
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