organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
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ISSN: 2056-9890
Volume 67| Part 5| May 2011| Page o1181

2,6-Bis[(S)-4-benzyl-4,5-di­hydro-1,3-oxazol-2-yl]pyridine

aLeibniz-Institut für Katalyse e. V. an der Universität Rostock, Albert-Einstein-Strasse 29a, 18059 Rostock, Germany
*Correspondence e-mail: kathrin.junge@catalysis.de

(Received 31 March 2011; accepted 14 April 2011; online 22 April 2011)

The commercially available title compound, C25H23N3O2, has been known since 1993 [Nesper et al. (1993[Nesper, R., Pregosin, P. S., Püntener, K. & Wörle, M. (1993). Helv. Chim. Acta, 76, 2239-2249.]). Helv. Chim. Acta, 76, 2239–2249], but has not been structurally characterized until now. In the free ligand, the N atoms of both oxazoline rings point in opposite directions. The phenyl rings make dihedral angles of 30.56 (5) and 84.57 (3)° with the pyridine ring and 72.85 (3)° with each other.

Related literature

For the synthesis, see: Nesper et al. (1993[Nesper, R., Pregosin, P. S., Püntener, K. & Wörle, M. (1993). Helv. Chim. Acta, 76, 2239-2249.]; 1996[Nesper, R., Pregosin, P., Püntener, K., Wörle, M. & Albinati, A. (1996). J. Organomet. Chem. 507, 85-101.]); Schaus & Jacobsen (2000[Schaus, S. E. & Jacobsen, E. N. (2000). Org. Lett. 2, 1001-1004.]); Towers et al. (2003[Towers, M. D. K. N., Woodgate, P. D. & Brimble, M. A. (2003). ARKIVOC, pp. 43-55.]); Meng et al. (2005[Meng, J.-C., Fokin, V. V. & Finn, M. G. (2005). Tetrahedron Lett. 46, 4543-4546.]); Hui et al. (2006[Hui, X.-P., Huang, J.-I., Chiou, S.-J. & Gau, H.-M. (2006). J. Chin. Chem. Soc. 53, 421-427.]). For crystal structures showing the same ligand coordinated to Pd(BF4)2 or AgBF4, see: Nesper et al. (1996[Nesper, R., Pregosin, P., Püntener, K., Wörle, M. & Albinati, A. (1996). J. Organomet. Chem. 507, 85-101.]); Provent et al. (1997[Provent, C., Hewage, S., Brand, G., Bernardinelli, G., Charbonnière, L. J. & Williams, A. F. (1997). Angew. Chem. Int. Ed. Engl. 36, 1287-1289.]). For applications in asymmetric catalysis, see: Desimoni et al. (2003[Desimoni, G., Faiti, G. & Quadrelli, P. (2003). Chem. Rev. 103, 3119-3154.]); Tse et al. (2006[Tse, M. K., Bhor, S., Klawonn, M., Anilkumar, G., Jiao, H., Döbler, C., Spannenberg, A., Mägerlein, W., Hugl, H. & Beller, M. (2006). Chem. Eur. J. 12, 1855-1874.]).

[Scheme 1]

Experimental

Crystal data
  • C25H23N3O2

  • Mr = 397.46

  • Orthorhombic, P 21 21 21

  • a = 7.0184 (2) Å

  • b = 13.2654 (3) Å

  • c = 21.5542 (8) Å

  • V = 2006.74 (10) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.09 mm−1

  • T = 150 K

  • 0.50 × 0.45 × 0.25 mm

Data collection
  • Stoe IPDS II diffractometer

  • 38412 measured reflections

  • 5433 independent reflections

  • 4254 reflections with I > 2σ(I)

  • Rint = 0.045

Refinement
  • R[F2 > 2σ(F2)] = 0.029

  • wR(F2) = 0.053

  • S = 0.86

  • 5433 reflections

  • 271 parameters

  • H-atom parameters constrained

  • Δρmax = 0.13 e Å−3

  • Δρmin = −0.18 e Å−3

Data collection: X-AREA (Stoe & Cie, 2005[Stoe & Cie (2005). X-AREA. Stoe & Cie, Darmstadt, Germany.]); cell refinement: X-AREA; data reduction: X-AREA; 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: XP in SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

The synthesis of chiral tridentate N,N,N-pyridine-2,6-bisoxazolines (pybox ligands) constitute a useful toolbox for the application in asymmetric catalysis (Desimoni et al., 2003). The title compound was used as part of our ongoing studies (Tse et al., 2006).

In contrast to the complexed ligand (Nesper et al., 1996; Provent et al., 1997) where all N atoms are pointed to the metal to permit coordination, in the free ligand the N atoms of both oxazoline rings point in the opposite direction (Fig. 1). The dihedral angle between the planes defined by C13 - C18 and C20 - C25 is 72.85 (3)°. The phenyl rings (C13 - C18 and C20 - C25) are twisted out of the N1, C4 - C8 plane by an angle of 30.56 (5)° and 84.57 (3)°, respectively. The absolute configuration has been assigned to correspond with that of the known chiral centres of the starting material.

Related literature top

For the synthesis, see: Nesper et al. (1993; 1996); Schaus & Jacobsen (2000); Towers et al. (2003); Meng et al. (2005); Hui et al. (2006). For crystal structures showing the same ligand coordinated to Pd(BF4)2 or AgBF4, see: Nesper et al. (1996); Provent et al. (1997). For applications in asymmetric catalysis, see: Desimoni et al. (2003); Tse et al. (2006).

Experimental top

The synthesis of the commercially available title compound was described by Nesper et al., 1993; Nesper et al., 1996; Schaus & Jacobsen, 2000; Towers et al., 2003; Meng et al., 2005 and Hui et al., 2006. The title compound was purchased from STREM and crystals were grown from a dichloromethane/hexane mixture. The solution was slowly evaporated to dryness for two days and colourless crystals suitable for X-ray analysis were isolated.

Refinement top

H atoms were placed in idealized positions with d(C—H) = 0.99 (CH2) and 0.95–1.00 Å (CH) and refined using a riding model with Uiso(H) fixed at 1.2 Ueq(C).

Computing details top

Data collection: X-AREA (Stoe & Cie, 2005); cell refinement: X-AREA (Stoe & Cie, 2005); data reduction: X-AREA (Stoe & Cie, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level.
2,6-Bis[(S)-4-benzyl-4,5-dihydro-1,3-oxazol-2-yl]pyridine top
Crystal data top
C25H23N3O2F(000) = 840
Mr = 397.46Dx = 1.316 Mg m3
Orthorhombic, P212121Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2abCell parameters from 7372 reflections
a = 7.0184 (2) Åθ = 1.8–29.6°
b = 13.2654 (3) ŵ = 0.09 mm1
c = 21.5542 (8) ÅT = 150 K
V = 2006.74 (10) Å3Prism, colourless
Z = 40.50 × 0.45 × 0.25 mm
Data collection top
Stoe IPDS II
diffractometer
4254 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.045
Graphite monochromatorθmax = 29.2°, θmin = 1.8°
ω scansh = 99
38412 measured reflectionsk = 1818
5433 independent reflectionsl = 2929
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)] = 0.029Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.053H-atom parameters constrained
S = 0.86 w = 1/[σ2(Fo2) + (0.0277P)2]
where P = (Fo2 + 2Fc2)/3
5433 reflections(Δ/σ)max = 0.001
271 parametersΔρmax = 0.13 e Å3
0 restraintsΔρmin = 0.18 e Å3
Crystal data top
C25H23N3O2V = 2006.74 (10) Å3
Mr = 397.46Z = 4
Orthorhombic, P212121Mo Kα radiation
a = 7.0184 (2) ŵ = 0.09 mm1
b = 13.2654 (3) ÅT = 150 K
c = 21.5542 (8) Å0.50 × 0.45 × 0.25 mm
Data collection top
Stoe IPDS II
diffractometer
4254 reflections with I > 2σ(I)
38412 measured reflectionsRint = 0.045
5433 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0290 restraints
wR(F2) = 0.053H-atom parameters constrained
S = 0.86Δρmax = 0.13 e Å3
5433 reflectionsΔρmin = 0.18 e Å3
271 parameters
Special details top

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
C10.08221 (18)0.78242 (8)0.86378 (6)0.0391 (3)
H1A0.04770.84700.84360.047*
H1B0.11240.79530.90790.047*
C20.07905 (16)0.70557 (7)0.85760 (5)0.0307 (2)
H20.16640.72740.82350.037*
C30.18890 (16)0.63775 (7)0.82495 (5)0.0271 (2)
C40.33449 (15)0.56927 (7)0.79877 (5)0.0271 (2)
C50.30631 (16)0.46567 (7)0.80236 (5)0.0320 (2)
H50.19930.43900.82380.038*
C60.43561 (16)0.40269 (8)0.77450 (5)0.0330 (3)
H60.41990.33160.77620.040*
C70.58872 (16)0.44469 (7)0.74402 (5)0.0302 (2)
H70.68010.40290.72410.036*
C80.60768 (16)0.54896 (7)0.74277 (5)0.0261 (2)
C90.76549 (16)0.59535 (7)0.70744 (4)0.0274 (2)
C101.02808 (19)0.58556 (8)0.64867 (6)0.0410 (3)
H10A1.04710.56880.60440.049*
H10B1.14830.57310.67150.049*
C110.96205 (16)0.69563 (8)0.65652 (5)0.0307 (2)
H110.90890.71990.61610.037*
C121.11831 (16)0.76752 (8)0.67706 (5)0.0308 (2)
H12A1.05950.83050.69270.037*
H12B1.19030.73660.71160.037*
C131.25418 (16)0.79284 (7)0.62524 (5)0.0287 (2)
C141.23770 (17)0.88259 (8)0.59240 (5)0.0341 (2)
H141.14070.92930.60320.041*
C151.36016 (18)0.90471 (10)0.54433 (6)0.0422 (3)
H151.34720.96650.52250.051*
C161.50168 (19)0.83760 (9)0.52768 (6)0.0415 (3)
H161.58550.85280.49440.050*
C171.52003 (17)0.74822 (9)0.55991 (6)0.0403 (3)
H171.61690.70160.54880.048*
C181.39795 (17)0.72647 (8)0.60832 (5)0.0352 (3)
H181.41260.66500.63040.042*
C190.19380 (17)0.69334 (8)0.91699 (5)0.0338 (2)
H19A0.30290.64770.90930.041*
H19B0.11270.66230.94940.041*
C200.26647 (15)0.79374 (7)0.93971 (5)0.0284 (2)
C210.19421 (16)0.83776 (8)0.99302 (5)0.0331 (3)
H210.09990.80311.01640.040*
C220.25669 (18)0.93129 (8)1.01295 (5)0.0369 (3)
H220.20510.96031.04960.044*
C230.39392 (18)0.98226 (8)0.97955 (6)0.0385 (3)
H230.43701.04660.99300.046*
C240.46803 (17)0.93922 (9)0.92658 (6)0.0380 (3)
H240.56320.97390.90370.046*
C250.40519 (17)0.84613 (8)0.90655 (5)0.0329 (2)
H250.45700.81750.86980.040*
N10.48293 (13)0.61177 (6)0.76977 (4)0.02706 (19)
N20.02005 (14)0.61231 (6)0.83845 (4)0.0311 (2)
N30.80484 (13)0.68788 (6)0.70200 (4)0.0307 (2)
O10.24182 (12)0.73528 (5)0.83241 (3)0.03401 (18)
O20.87275 (12)0.52786 (5)0.67492 (4)0.0402 (2)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0401 (7)0.0291 (5)0.0482 (7)0.0040 (5)0.0204 (6)0.0039 (5)
C20.0318 (6)0.0266 (5)0.0337 (6)0.0005 (4)0.0013 (5)0.0007 (4)
C30.0318 (6)0.0241 (5)0.0255 (5)0.0043 (4)0.0004 (5)0.0029 (4)
C40.0289 (6)0.0273 (5)0.0251 (5)0.0027 (4)0.0007 (4)0.0015 (4)
C50.0320 (6)0.0283 (5)0.0357 (6)0.0042 (5)0.0018 (5)0.0048 (4)
C60.0398 (7)0.0218 (5)0.0375 (6)0.0016 (5)0.0023 (5)0.0023 (4)
C70.0332 (6)0.0264 (5)0.0310 (6)0.0034 (4)0.0003 (5)0.0002 (4)
C80.0289 (6)0.0249 (5)0.0245 (5)0.0005 (4)0.0013 (4)0.0006 (4)
C90.0293 (6)0.0266 (5)0.0262 (5)0.0016 (5)0.0004 (5)0.0035 (4)
C100.0403 (7)0.0347 (6)0.0480 (7)0.0067 (5)0.0162 (6)0.0078 (5)
C110.0302 (6)0.0337 (5)0.0282 (5)0.0001 (5)0.0037 (5)0.0020 (4)
C120.0330 (6)0.0295 (5)0.0299 (5)0.0017 (5)0.0008 (5)0.0009 (4)
C130.0255 (6)0.0297 (5)0.0310 (5)0.0031 (4)0.0036 (5)0.0033 (4)
C140.0294 (6)0.0325 (5)0.0404 (6)0.0010 (5)0.0008 (5)0.0025 (4)
C150.0402 (7)0.0439 (7)0.0424 (7)0.0079 (6)0.0013 (6)0.0104 (5)
C160.0349 (7)0.0544 (7)0.0351 (6)0.0136 (6)0.0054 (6)0.0025 (5)
C170.0264 (6)0.0450 (7)0.0494 (7)0.0017 (5)0.0039 (6)0.0128 (5)
C180.0297 (6)0.0315 (6)0.0444 (7)0.0004 (5)0.0007 (5)0.0013 (5)
C190.0294 (6)0.0292 (5)0.0429 (6)0.0006 (5)0.0083 (5)0.0054 (5)
C200.0228 (5)0.0304 (5)0.0320 (5)0.0024 (5)0.0068 (5)0.0071 (4)
C210.0263 (6)0.0406 (6)0.0323 (6)0.0000 (5)0.0018 (5)0.0084 (4)
C220.0376 (7)0.0416 (6)0.0314 (5)0.0076 (5)0.0043 (5)0.0013 (5)
C230.0416 (7)0.0297 (6)0.0443 (7)0.0022 (5)0.0132 (6)0.0028 (5)
C240.0311 (6)0.0396 (6)0.0433 (7)0.0069 (5)0.0001 (5)0.0101 (5)
C250.0289 (6)0.0364 (6)0.0335 (6)0.0028 (5)0.0015 (5)0.0031 (5)
N10.0295 (5)0.0247 (4)0.0270 (4)0.0009 (4)0.0019 (4)0.0001 (3)
N20.0297 (5)0.0268 (4)0.0370 (5)0.0031 (4)0.0034 (4)0.0014 (4)
N30.0300 (5)0.0277 (4)0.0345 (5)0.0021 (4)0.0052 (4)0.0030 (4)
O10.0351 (4)0.0253 (3)0.0416 (4)0.0049 (3)0.0136 (4)0.0037 (3)
O20.0407 (5)0.0283 (4)0.0515 (5)0.0052 (4)0.0187 (4)0.0111 (3)
Geometric parameters (Å, º) top
C1—O11.4503 (14)C12—C131.5065 (15)
C1—C21.5290 (17)C12—H12A0.9900
C1—H1A0.9900C12—H12B0.9900
C1—H1B0.9900C13—C181.3879 (15)
C2—N21.4781 (14)C13—C141.3899 (14)
C2—C191.5211 (15)C14—C151.3778 (16)
C2—H21.0000C14—H140.9500
C3—N21.2660 (14)C15—C161.3813 (18)
C3—O11.3556 (11)C15—H150.9500
C3—C41.4790 (14)C16—C171.3801 (17)
C4—N11.3394 (13)C16—H160.9500
C4—C51.3905 (14)C17—C181.3808 (16)
C5—C61.3719 (15)C17—H170.9500
C5—H50.9500C18—H180.9500
C6—C71.3773 (15)C19—C201.5078 (14)
C6—H60.9500C19—H19A0.9900
C7—C81.3898 (13)C19—H19B0.9900
C7—H70.9500C20—C211.3852 (15)
C8—N11.3415 (13)C20—C251.3934 (15)
C8—C91.4784 (15)C21—C221.3843 (16)
C9—N31.2636 (13)C21—H210.9500
C9—O21.3636 (12)C22—C231.3796 (17)
C10—O21.4472 (14)C22—H220.9500
C10—C111.5413 (15)C23—C241.3784 (17)
C10—H10A0.9900C23—H230.9500
C10—H10B0.9900C24—C251.3806 (15)
C11—N31.4796 (14)C24—H240.9500
C11—C121.5193 (16)C25—H250.9500
C11—H111.0000
O1—C1—C2104.10 (8)C11—C12—H12B109.1
O1—C1—H1A110.9H12A—C12—H12B107.9
C2—C1—H1A110.9C18—C13—C14118.04 (10)
O1—C1—H1B110.9C18—C13—C12120.90 (9)
C2—C1—H1B110.9C14—C13—C12121.05 (10)
H1A—C1—H1B109.0C15—C14—C13120.90 (11)
N2—C2—C19113.26 (8)C15—C14—H14119.6
N2—C2—C1103.54 (9)C13—C14—H14119.6
C19—C2—C1112.94 (9)C14—C15—C16120.44 (11)
N2—C2—H2109.0C14—C15—H15119.8
C19—C2—H2109.0C16—C15—H15119.8
C1—C2—H2109.0C17—C16—C15119.34 (11)
N2—C3—O1118.92 (10)C17—C16—H16120.3
N2—C3—C4124.80 (9)C15—C16—H16120.3
O1—C3—C4116.24 (9)C16—C17—C18120.13 (11)
N1—C4—C5123.55 (10)C16—C17—H17119.9
N1—C4—C3117.18 (8)C18—C17—H17119.9
C5—C4—C3119.17 (10)C17—C18—C13121.14 (10)
C6—C5—C4118.91 (10)C17—C18—H18119.4
C6—C5—H5120.5C13—C18—H18119.4
C4—C5—H5120.5C20—C19—C2110.99 (8)
C5—C6—C7118.60 (9)C20—C19—H19A109.4
C5—C6—H6120.7C2—C19—H19A109.4
C7—C6—H6120.7C20—C19—H19B109.4
C6—C7—C8119.11 (10)C2—C19—H19B109.4
C6—C7—H7120.4H19A—C19—H19B108.0
C8—C7—H7120.4C21—C20—C25118.10 (10)
N1—C8—C7123.18 (10)C21—C20—C19121.19 (10)
N1—C8—C9116.99 (8)C25—C20—C19120.69 (10)
C7—C8—C9119.74 (9)C22—C21—C20121.29 (11)
N3—C9—O2118.00 (9)C22—C21—H21119.4
N3—C9—C8128.02 (9)C20—C21—H21119.4
O2—C9—C8113.89 (8)C23—C22—C21119.90 (11)
O2—C10—C11103.39 (9)C23—C22—H22120.1
O2—C10—H10A111.1C21—C22—H22120.1
C11—C10—H10A111.1C24—C23—C22119.52 (11)
O2—C10—H10B111.1C24—C23—H23120.2
C11—C10—H10B111.1C22—C23—H23120.2
H10A—C10—H10B109.0C23—C24—C25120.59 (11)
N3—C11—C12112.88 (9)C23—C24—H24119.7
N3—C11—C10103.36 (8)C25—C24—H24119.7
C12—C11—C10114.18 (10)C24—C25—C20120.60 (11)
N3—C11—H11108.7C24—C25—H25119.7
C12—C11—H11108.7C20—C25—H25119.7
C10—C11—H11108.7C4—N1—C8116.66 (8)
C13—C12—C11112.38 (9)C3—N2—C2106.35 (8)
C13—C12—H12A109.1C9—N3—C11106.97 (8)
C11—C12—H12A109.1C3—O1—C1104.79 (8)
C13—C12—H12B109.1C9—O2—C10105.64 (8)

Experimental details

Crystal data
Chemical formulaC25H23N3O2
Mr397.46
Crystal system, space groupOrthorhombic, P212121
Temperature (K)150
a, b, c (Å)7.0184 (2), 13.2654 (3), 21.5542 (8)
V3)2006.74 (10)
Z4
Radiation typeMo Kα
µ (mm1)0.09
Crystal size (mm)0.50 × 0.45 × 0.25
Data collection
DiffractometerStoe IPDS II
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
38412, 5433, 4254
Rint0.045
(sin θ/λ)max1)0.686
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.029, 0.053, 0.86
No. of reflections5433
No. of parameters271
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.13, 0.18

Computer programs: X-AREA (Stoe & Cie, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), XP in SHELXTL (Sheldrick, 2008).

 

References

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Volume 67| Part 5| May 2011| Page o1181
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