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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 66| Part 1| January 2010| Page o156
doi:10.1107/S1600536809052775

An inter­molecular dative B←N bond in 5-(4,4,5,5-tetra­methyl-1,3,2-dioxa­borolan-2-yl)-1,3-thia­zole

Jana Sopková-de Oliveira Santos,a* Nicolas Primas,a Jean-François Lohier,b Alexandre Bouillonc and Sylvain Raulta

aCentre d'Études et de Recherche sur le Médicament de Normandie (CERMN), UPRES EA-4258, FR CNRS INC3M, Université de Caen, bv becquerel, 14032 Caen, France, bLaboratoire de Chimie Moléculaire et Thio-organique, UMR CNRS 6507, UPRES EA-4258, FR CNRS 3038 INC3M, ENSICAEN - Université de Caen, 14050 Caen, France, and cBoroChem S.A.S., Immeuble Emergence, 7 rue Alfred Kastler, 14000 Caen, France
*Correspondence e-mail: jana.sopkova@unicaen.fr

(Received 29 October 2009; accepted 8 December 2009; online 16 December 2009)

The title compound, C9H14BNO2S, is in an unusual bend conformation and the B atom of one mol­ecule within the crystal forms an inter­molecular dative bond with the N atom of a neighbouring mol­ecule, an infrequent phenomenon in boronic derivative crystals.

Related literature

For related natural compounds, see: Dondoni & Merino (1996[Dondoni, A. & Merino, P. (1996). Comprehensive Heterocyclic Chemistry II, edited by I. Shinkai, Vol. 3, pp. 373-474. Oxford: Elsevier.]); Faulkner (1998[Faulkner, D. J. (1998). Nat. Prod. Rep. 15, 113-158.]); Hutchinson et al. (2000[Hutchinson, I., Stevens, M. F. G. & Westwell, A. D. (2000). Tetrahedron Lett. 41, 425-428.]); Kalgutkar et al. (1996[Kalgutkar, A. S., Crews, B. C. & Marnett, L. J. (1996). Biochemistry, 35, 9076-9082.]); Ogino et al. (1996[Ogino, J., Moore, R. E., Patterson, G. M. & Smith, C. D. J. (1996). J. Nat. Prod. 59, 581-586.]); Williams & Jacobs (1993[Williams, A. B. & Jacobs, R. S. (1993). Cancer Lett. 71, 97-102.]). For boronic esters, see: Allen (2002[Allen, F. H. (2002). Acta Cryst. B58, 380-388.]); Höpfl (1999[Höpfl, H. (1999). J. Organomet. Chem. 581, 129-149.]); Hall (2005[Hall, D. G. (2005). In Boronic Acids. New York: VCH.]); Rettig & Trotter (1975[Rettig, S. V. & Trotter, J. (1975). Can. J. Chem. 53, 1393-1401.]); Sopková-de Oliveira Santos et al. (2003a[Sopková-de Oliveira Santos, J., Bouillon, A., Lancelot, J.-C. & Rault, S. (2003a). Acta Cryst. C59, o596-o597.],b[Sopková-de Oliveira Santos, J., Lancelot, J.-C., Bouillon, A. & Rault, S. (2003b). Acta Cryst. C59, o111-o113.]). For details of the synthesis, see: Primas et al. (2008[Primas, N., Mahatsekake, C., Bouillon, A., Lancelot, J. C., Sopková-de Oliveira Santos, J., Lohier, J. F. & Rault, S. (2008). Tetrahedron, 64, 4596-4601.], 2009[Primas, N., Bouillon, A., Lancelot, J. C., El-Kashef, H. & Rault, S. (2009). Tetrahedron, 65, 5739-5746.]).

[Scheme 1]

Experimental

Crystal data

  • C9H14BNO2S

  • Mr = 211.08

  • Monoclinic, P 21 /c

  • a = 12.6169 (3) Å

  • b = 7.9845 (2) Å

  • c = 12.6679 (3) Å

  • β = 119.064 (1)°

  • V = 1115.46 (5) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.26 mm−1

  • T = 296 K

  • 0.53 × 0.36 × 0.32 mm
Data collection

  • Bruker APEXII CCD area-detector diffractometer

  • 42058 measured reflections

  • 5399 independent reflections

  • 3895 reflections with I > 2σ(I)

  • Rint = 0.023
Refinement

  • R[F2 > 2σ(F2)] = 0.046

  • wR(F2) = 0.159

  • S = 1.04

  • 5399 reflections

  • 139 parameters

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

  • Δρmax = 0.87 e Å−3

  • Δρmin = −0.68 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
C2—H2⋯O1i 0.94 (2) 2.36 (2) 3.2446 (14) 157.5 (17)
Symmetry code: (i) [x, -y+{\script{3\over 2}}, z+{\script{1\over 2}}].

Data collection: APEX2 (Bruker, 2006[Bruker (2006). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2006[Bruker (2006). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; 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: ORTEP-3 (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]) and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809052775/dn2507sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809052775/dn2507Isup2.hkl

checkCIF report


Comment top

The thiazole ring is a widespread heterocycle found in various biologically active natural products like vitamin B1 and penicillins (Dondoni & Merino, 1996; Kalgutkar et al., 1996; Hutchinson et al., 2000), and also in many peptides and peptolides isolated from marine organisms (Ogino et al., 1996; Williams & Jacobs, 1993; Faulkner, 1998). The search of new regioselective methods for the preparation of new thiazole derivatives is always a matter of interest.

As a part of our study of 1,3-azolylboronic derivatives, we are focused on the synthesis of the new thiazol-5-ylboronic acid pinacol ester (Primas et al., 2009). Indeed, this new boronic ester permits a facile synthetic route to 5-(het)arylthiazoles via a Suzuki-Miyaura cross-coupling reaction with various (het)halides. This boronic ester was stable under aqueous conditions in the Suzuki process (Primas et al., 2008). To date only a few crystallographic studies have been published on such heterocyclic compounds. We carried out this study with the aim to confirm the structure of the title compound and to find an explanation to its greater stability than its imidazole analogue (Primas et al., 2008).

The structure shows that the molecule is in an unusual bent conformation, thus the thiazole cycle and the dioxaborolane ring of the boronic ester forms an angle of about 55.0(0.05)° (Fig. 1). Usually, in the boronic esters deposed in Cambridge Structural Database (CSD, Version; Allen 2002) as well as in the ones solved previously in our laboratory, the ester ring is coplanar to the aromatic ring (Sopková-de Oliveira Santos et al., 2003a,b).

In the crystal structure the boron atom is the peak bending, and it is committed to the B←N dative bond with N of the neighbouring molecule (-x,y - 1/2, -z + 1/2), which leads to a tetracoordinated B atom in the crystal. As it was already published (Hall, 2005), the formation of tetracoordinate B influences all bond lenghts in the boron vicinity. The observed B—O bond lengths, 1.4351 (13)Å and 1.4447 (13) Å, are in agreement with the ones reported when B is tetracoordinated (Hall, 2005), between 1.43–1.47 Å. The observed C—B distance is about 1.6207 (15)Å which is closed to the usually observed value for tetracoordinate boron, 1.613Å (Rettig & Trotter, 1975). However, the B←N dative bond observed in the crystal is shorter with respect to the published value, its length is about 1.6354 (14) Å. Furthermore, the calculated parameter describing the tetrahedral character of boron (THCDA; Höpfl, 1999) is in the title compound of 81% which is a high value and shows that the formed B←N dative bond is a strong one. The existence of this strong B←N dative bond could explain the stability of this boronic ester even not only in the solid state but also in the solution. Further studies concerning this phenomenon are currently in progress.

The dioxaborolane ring of the boronic ester is in a half-chair conformation with an O1—C6—C7—O2 torsion angle of about -37.74(0.10)°.

The crucial element of the crystal packing is of course this intermolecular dative B←N bond. The interacting neighbouring molecules form a strand along the b axis (Fig. 2). Some electrostatic interactions occur between these strands, the strongest seems to be an electrostatic interaction between O1 and H2—C2 of symmetrically related molecule (Table 2, Fig. 3).

Related literature top

For related natural compounds, see: Dondoni & Merino (1996); Faulkner (1998); Hutchinson et al. (2000); Kalgutkar et al. (1996); Ogino et al. (1996); Williams & Jacobs (1993). For boronic esters, see: Allen (2002); Höpfl (1999); Hall (2005); Rettig & Trotter (1975); Sopková-de Oliveira Santos et al. (2003a,b). For details of the synthesis, see: Primas et al. (2008, 2009).

Experimental top

The title compound was synthesized from 2-trimethylsilylthiazole using the method described by Primas et al. (2009). Crystals of (I) suitable for X-ray analysis were obtained by slow evaporation from diethyl ether at room temperature.

Refinement top

All non-hydrogen atoms were refined anisotropically. All H atoms were determined via difference Fourier map and refined with isotropic atomic displacement parameters with exception on H atoms on methyl groups which were calculated and fixed on the atoms in the ideal geometry (distance 0.96 Å).

Computing details top

Data collection: APEX2 (Bruker, 2006); cell refinement: SAINT (Bruker, 2006); data reduction: SAINT (Bruker, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. View of the title compound showing the labelling scheme of the non-hydrogen atoms. Thermal ellipsoids are shown at the 50% probability levels; hydrogen atoms are drawn as small circles of arbitrary radii.
[Figure 2] Fig. 2. Partial packing view showing the chain formed by intermolecular dative B←N bonds. [Symmetry code: (i) -x, y - 1/2, -z + 1/2)]
[Figure 3] Fig. 3. Packing view showing the C-H···O hydrogen bonds connecting the chain. H atoms not involved in hydrogen bondings have been omitted for clarity. H bonds are shown as dashed lines.
5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1,3-thiazole top
Crystal data top
C9H14BNO2SF(000) = 448
Mr = 211.08Dx = 1.257 Mg m−3
Monoclinic, P21/cMelting point: 371 K
Hall symbol: -P 2ybcMo Kα radiation, λ = 0.71073 Å
a = 12.6169 (3) ÅCell parameters from 9543 reflections
b = 7.9845 (2) Åθ = 3.2–35.8°
c = 12.6679 (3) ŵ = 0.26 mm−1
β = 119.064 (1)°T = 296 K
V = 1115.46 (5) Å3Plate, colourless
Z = 40.53 × 0.36 × 0.32 mm
Data collection top
Bruker APEXII CCD area-detector
diffractometer		3895 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.023
Graphite monochromatorθmax = 36.4°, θmin = 1.9°
ϕ and ω scansh = −21→21
42058 measured reflectionsk = −10→13
5399 independent reflectionsl = −21→21
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)] = 0.046Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.159H atoms treated by a mixture of independent and constrained refinement
S = 1.04 w = 1/[σ2(Fo2) + (0.0814P)2 + 0.2917P]
where P = (Fo2 + 2Fc2)/3
5399 reflections(Δ/σ)max < 0.001
139 parametersΔρmax = 0.87 e Å−3
0 restraintsΔρmin = −0.68 e Å−3
Crystal data top
C9H14BNO2SV = 1115.46 (5) Å3
Mr = 211.08Z = 4
Monoclinic, P21/cMo Kα radiation
a = 12.6169 (3) ŵ = 0.26 mm−1
b = 7.9845 (2) ÅT = 296 K
c = 12.6679 (3) Å0.53 × 0.36 × 0.32 mm
β = 119.064 (1)°
Data collection top
Bruker APEXII CCD area-detector
diffractometer		3895 reflections with I > 2σ(I)
42058 measured reflectionsRint = 0.023
5399 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0460 restraints
wR(F2) = 0.159H atoms treated by a mixture of independent and constrained refinement
S = 1.04Δρmax = 0.87 e Å−3
5399 reflectionsΔρmin = −0.68 e Å−3
139 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
S10.16573 (3)0.62779 (5)0.44438 (3)0.04720 (12)
C20.06243 (12)0.77776 (17)0.42356 (10)0.0386 (3)
H20.0698 (18)0.848 (3)0.4859 (19)0.057 (5)*
N3−0.02480 (8)0.78577 (10)0.31137 (8)0.02725 (16)
C4−0.00940 (10)0.67047 (14)0.23876 (10)0.0305 (2)
H4−0.0704 (14)0.667 (2)0.1570 (15)0.040 (4)*
C50.08968 (9)0.57082 (12)0.29535 (9)0.02743 (18)
B10.13725 (10)0.41927 (13)0.24402 (10)0.02591 (19)
O20.24223 (7)0.34057 (10)0.33978 (7)0.02967 (16)
O10.16342 (7)0.46160 (10)0.14816 (7)0.03061 (16)
C60.29217 (10)0.43640 (17)0.19662 (10)0.0343 (2)
C80.31785 (16)0.3921 (3)0.09484 (14)0.0580 (4)
H8A0.40320.37330.12710.087*
H8B0.29250.48270.03780.087*
H8C0.27410.29240.05510.087*
C90.35543 (14)0.6010 (2)0.25586 (15)0.0492 (3)
H9A0.32130.69060.19850.074*
H9B0.44050.59190.28210.074*
H9C0.34410.62380.32410.074*
C70.31999 (10)0.29495 (15)0.29088 (10)0.0332 (2)
C100.44987 (12)0.2890 (2)0.39326 (14)0.0501 (3)
H10A0.46740.38910.44080.075*
H10B0.50410.28070.36050.075*
H10C0.46020.19330.44330.075*
C110.28385 (15)0.12147 (19)0.23354 (16)0.0519 (4)
H11A0.28240.04430.29090.078*
H11B0.34160.08420.20990.078*
H11C0.20480.12690.16380.078*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
S10.04648 (19)0.0520 (2)0.02922 (15)0.02133 (14)0.00746 (12)−0.00218 (12)
C20.0423 (6)0.0395 (6)0.0296 (5)0.0097 (5)0.0139 (4)−0.0041 (4)
N30.0284 (4)0.0240 (3)0.0294 (4)0.0009 (3)0.0141 (3)−0.0013 (3)
C40.0298 (4)0.0294 (4)0.0292 (4)0.0042 (3)0.0119 (4)−0.0028 (3)
C50.0281 (4)0.0246 (4)0.0301 (4)0.0011 (3)0.0146 (3)0.0003 (3)
B10.0258 (4)0.0243 (4)0.0283 (4)0.0008 (3)0.0136 (4)0.0013 (3)
O20.0293 (3)0.0315 (3)0.0278 (3)0.0057 (3)0.0136 (3)0.0029 (3)
O10.0275 (3)0.0366 (4)0.0288 (3)−0.0002 (3)0.0145 (3)0.0041 (3)
C60.0288 (4)0.0471 (6)0.0304 (4)−0.0017 (4)0.0171 (4)−0.0033 (4)
C80.0505 (8)0.0937 (13)0.0402 (7)0.0083 (8)0.0303 (6)−0.0025 (7)
C90.0424 (7)0.0543 (8)0.0497 (7)−0.0174 (6)0.0214 (6)−0.0024 (6)
C70.0279 (4)0.0376 (5)0.0312 (5)0.0053 (4)0.0120 (4)−0.0054 (4)
C100.0312 (5)0.0667 (9)0.0426 (6)0.0123 (6)0.0103 (5)−0.0041 (6)
C110.0541 (8)0.0399 (6)0.0550 (8)0.0094 (6)0.0212 (7)−0.0123 (6)
Geometric parameters (Å, º) top
S1—C21.6936 (12)C6—C71.5548 (17)
S1—C51.7122 (11)C8—H8A0.9600
C2—N31.3097 (15)C8—H8B0.9600
C2—H20.94 (2)C8—H8C0.9600
N3—C41.3803 (13)C9—H9A0.9600
N3—B1i1.6354 (14)C9—H9B0.9600
C4—C51.3561 (14)C9—H9C0.9600
C4—H40.945 (16)C7—C101.5182 (17)
C5—B11.6207 (15)C7—C111.5273 (18)
B1—O21.4351 (13)C10—H10A0.9600
B1—O11.4447 (13)C10—H10B0.9600
B1—N3ii1.6354 (14)C10—H10C0.9600
O2—C71.4386 (13)C11—H11A0.9600
O1—C61.4448 (13)C11—H11B0.9600
C6—C81.5159 (17)C11—H11C0.9600
C6—C91.5318 (19)
C2—S1—C592.26 (5)H8A—C8—H8B109.5
N3—C2—S1112.39 (8)C6—C8—H8C109.5
N3—C2—H2125.0 (13)H8A—C8—H8C109.5
S1—C2—H2122.6 (13)H8B—C8—H8C109.5
C2—N3—C4111.99 (9)C6—C9—H9A109.5
C2—N3—B1i126.44 (9)C6—C9—H9B109.5
C4—N3—B1i121.50 (8)H9A—C9—H9B109.5
C5—C4—N3115.54 (10)C6—C9—H9C109.5
C5—C4—H4127.7 (11)H9A—C9—H9C109.5
N3—C4—H4116.7 (11)H9B—C9—H9C109.5
C4—C5—B1130.68 (9)O2—C7—C10108.61 (10)
C4—C5—S1107.81 (8)O2—C7—C11109.02 (11)
B1—C5—S1121.49 (7)C10—C7—C11109.07 (12)
O2—B1—O1108.61 (8)O2—C7—C6101.54 (8)
O2—B1—C5110.94 (8)C10—C7—C6115.23 (12)
O1—B1—C5116.29 (8)C11—C7—C6112.94 (11)
O2—B1—N3ii109.23 (8)C7—C10—H10A109.5
O1—B1—N3ii107.26 (8)C7—C10—H10B109.5
C5—B1—N3ii104.22 (8)H10A—C10—H10B109.5
B1—O2—C7106.82 (8)C7—C10—H10C109.5
B1—O1—C6106.21 (8)H10A—C10—H10C109.5
O1—C6—C8109.38 (10)H10B—C10—H10C109.5
O1—C6—C9107.41 (11)C7—C11—H11A109.5
C8—C6—C9109.94 (12)C7—C11—H11B109.5
O1—C6—C7102.43 (8)H11A—C11—H11B109.5
C8—C6—C7114.97 (12)C7—C11—H11C109.5
C9—C6—C7112.19 (10)H11A—C11—H11C109.5
C6—C8—H8A109.5H11B—C11—H11C109.5
C6—C8—H8B109.5
O1—C6—C7—O2−37.74 (10)
Symmetry codes: (i) −x, y+1/2, −z+1/2; (ii) −x, y−1/2, −z+1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C2—H2···O1iii0.94 (2)2.36 (2)3.2446 (14)157.5 (17)
Symmetry code: (iii) x, −y+3/2, z+1/2.

Experimental details

Crystal data
Chemical formulaC9H14BNO2S
Mr211.08
Crystal system, space groupMonoclinic, P21/c
Temperature (K)296
a, b, c (Å)12.6169 (3), 7.9845 (2), 12.6679 (3)
β (°) 119.064 (1)
V (Å3)1115.46 (5)
Z4
Radiation typeMo Kα
µ (mm−1)0.26
Crystal size (mm)0.53 × 0.36 × 0.32
Data collection
DiffractometerBruker APEXII CCD area-detector
diffractometer
Absorption correction–
No. of measured, independent and
observed [I > 2σ(I)] reflections		42058, 5399, 3895
Rint0.023
(sin θ/λ)max (Å−1)0.834
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.046, 0.159, 1.04
No. of reflections5399
No. of parameters139
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)0.87, −0.68

Computer programs: APEX2 (Bruker, 2006), SAINT (Bruker, 2006), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C2—H2···O1i0.94 (2)2.36 (2)3.2446 (14)157.5 (17)
Symmetry code: (i) x, −y+3/2, z+1/2.
 

Acknowledgements

For the mol­ecular modelling software, we thank the CRIHAN, the `Région Haute-Normandie' and the European Community (FEDER).

References

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ISSN: 2056-9890
Volume 66| Part 1| January 2010| Page o156
doi:10.1107/S1600536809052775
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