2-(2-Cyclo­hex-1-enyl­vinyl)[1,3,6,2]­diox­aza­borocane

In the title compound, C₁₂H₂₀BNO₂, the B—N distance is 1.6720 (17) Å. Molecules are linked through intermolecular N—H...O hydrogen bonds to form infinite chains with an N...O distance of 2.8581 (13) Å.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.040
• wR factor = 0.102
• Data-to-parameter ratio = 16.7

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

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S1. Comment

The Diels–Alder (DA) reaction is a powerful method for the selective formation of functionalized cyclohexene derivatives. Dienylboronates have proved to be effective dienes for intermolecular DA reactions with reactive dienophiles (Vaultier et al., 1987; Tailor & Hall, 2000) or intramolecular tethered DA reactions with unreactive dienophiles (Batey et al., 1999). The synthetic utility of these dienes, though, can be limited due to their susceptibility to air and/or moisture. We are interested in developing stable dienylboronates that function as versatile equivalents for hetero-substituted dienes. The title compound, (I), fulfills the above criteria and is also amenable to long-term storage. Previously, it had been shown that compounds that are structurally related to (I) show promise in asymmetric Diels–Alder reactions (Wang, 1991).

The structure of the title compound is similar to that of the compound 4,5,7,8-tetrahydro-2-(2-propenyl)-6H-[1,3,6,2]dioxazaborocine, (II), which we have already determined (Thadani et al., 2001). As in (II), moleclues of (I) are linked by intermolecular N—H···O hydrogen bonds to form infinite chains through glide-plane transformations along the c axis. The N···O distance in (I) is 2.8581 (13) Å for N1.·O1 (see Fig. 2 and Table 2). The B1—N1 distance is 1.6720 (17) Å in (I) and 1.659 (4) Å in (II). A list of references for other dioxazaborocine compounds is included in our paper by Thadani et al. (2001).

S2. Experimental

To a solution of dicyclohexyl (2-cyclohex-1-enylvinyl)boronate (Batey et al., 1999) in a minimal amount of ⁱPrOH was added diethanolamine (1 equivalent). The reaction mixture was stirred for 2 h at room temperature. The solvent was then removed under reduced pressure and the resulting solid recrystallized from acetonitrile. Compound (I) was obtained in 51% yield as clear colourless needles.

S3. Refinement

H atoms were included in calculated positions with C—H distances ranging from 0.95 to 0.99 Å and an N—H distance of 0.93 Å.

Computing details

Data collection: COLLECT (Nonius, 2001); cell refinement: DENZO-SMN (Otwinowski & Minor, 1997); data reduction: DENZO-SMN; program(s) used to solve structure: SHELXTL (Sheldrick, 1999); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. View of (I) showing the atom-labelling scheme. Ellipsoids are shown at the 50% probability level.
	Fig. 2. View of the hydrogen bonding in (I) showing the infinite chains in the z direction. Ellipsoids are at the 50% probability level.

2-(2-Cyclohex-1-enylvinyl)-[1,3,6,2]dioxazaborocane

Crystal data

C12H20BNO2	F(000) = 480
Mr = 221.10	Dx = 1.227 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 11.6372 (3) Å	Cell parameters from 11487 reflections
b = 10.4879 (5) Å	θ = 4.2–26.4°
c = 9.9749 (4) Å	µ = 0.08 mm^−1
β = 100.657 (3)°	T = 100 K
V = 1196.44 (8) Å^3	Needle, colourless
Z = 4	0.32 × 0.28 × 0.19 mm

Data collection

Nonius KappaCCD diffractometer	2441 independent reflections
Radiation source: fine-focus sealed tube	1870 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.056
Detector resolution: 9 pixels mm^-1	θmax = 26.4°, θmin = 4.2°
ϕ scans and ω scans with κ offsets	h = −14→14
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997)	k = −13→13
Tmin = 0.975, Tmax = 0.985	l = −12→12
11487 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.040	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.102	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0485P)^2 + 0.168P] where P = (Fo^2 + 2Fc^2)/3
2441 reflections	(Δ/σ)max = 0.002
146 parameters	Δρmax = 0.21 e Å^−3
0 restraints	Δρmin = −0.16 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
O1	0.16422 (8)	0.23107 (8)	0.18954 (8)	0.0241 (2)
O2	−0.01799 (8)	0.31670 (9)	0.24368 (8)	0.0265 (2)
N1	0.11100 (9)	0.19011 (10)	0.41066 (10)	0.0225 (3)
H1B	0.1469	0.2218	0.4952	0.027*
C1	0.17778 (11)	0.42592 (12)	0.34248 (12)	0.0243 (3)
H1A	0.1439	0.4801	0.4009	0.029*
C2	0.27985 (11)	0.46122 (13)	0.31166 (13)	0.0260 (3)
H2A	0.3118	0.4054	0.2530	0.031*
C3	0.34929 (12)	0.57572 (13)	0.35704 (13)	0.0271 (3)
C4	0.45275 (13)	0.59339 (16)	0.32027 (15)	0.0386 (4)
H4A	0.4775	0.5313	0.2623	0.046*
C5	0.53303 (15)	0.70396 (19)	0.36368 (18)	0.0520 (5)
H5A	0.5346	0.7596	0.2839	0.062*
H5B	0.6133	0.6714	0.3956	0.062*
C6	0.49658 (14)	0.78183 (16)	0.47571 (17)	0.0434 (4)
H6A	0.5346	0.8666	0.4797	0.052*
H6B	0.5233	0.7389	0.5644	0.052*
C7	0.36482 (13)	0.79885 (15)	0.45241 (17)	0.0399 (4)
H7A	0.3383	0.8445	0.3653	0.048*
H7B	0.3438	0.8511	0.5269	0.048*
C8	0.30334 (12)	0.67015 (13)	0.44774 (14)	0.0306 (3)
H8A	0.3137	0.6350	0.5413	0.037*
H8B	0.2185	0.6826	0.4143	0.037*
C9	0.15847 (12)	0.09742 (12)	0.21281 (13)	0.0266 (3)
H9A	0.2191	0.0516	0.1739	0.032*
H9B	0.0807	0.0633	0.1714	0.032*
C10	0.17994 (11)	0.08361 (13)	0.36696 (13)	0.0261 (3)
H10A	0.1518	0.0001	0.3941	0.031*
H10B	0.2641	0.0924	0.4065	0.031*
C11	−0.07669 (12)	0.27914 (14)	0.34981 (13)	0.0279 (3)
H11A	−0.1602	0.2614	0.3133	0.033*
H11B	−0.0714	0.3468	0.4199	0.033*
C12	−0.01461 (11)	0.15944 (13)	0.40953 (12)	0.0255 (3)
H12A	−0.0287	0.1432	0.5029	0.031*
H12B	−0.0400	0.0842	0.3517	0.031*
B1	0.10880 (13)	0.29991 (14)	0.28868 (14)	0.0232 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0324 (5)	0.0202 (5)	0.0214 (5)	0.0002 (4)	0.0095 (4)	0.0000 (3)
O2	0.0287 (5)	0.0301 (6)	0.0215 (5)	0.0024 (4)	0.0070 (4)	0.0048 (4)
N1	0.0267 (6)	0.0215 (6)	0.0196 (5)	−0.0013 (4)	0.0046 (4)	0.0001 (4)
C1	0.0329 (7)	0.0220 (7)	0.0191 (6)	0.0038 (5)	0.0077 (5)	0.0016 (5)
C2	0.0302 (7)	0.0235 (7)	0.0251 (6)	0.0031 (6)	0.0068 (5)	0.0005 (5)
C3	0.0312 (7)	0.0267 (8)	0.0235 (7)	0.0000 (6)	0.0054 (5)	0.0027 (5)
C4	0.0367 (8)	0.0434 (10)	0.0382 (8)	−0.0080 (7)	0.0136 (6)	−0.0081 (7)
C5	0.0448 (10)	0.0616 (12)	0.0526 (10)	−0.0225 (9)	0.0171 (8)	−0.0120 (9)
C6	0.0413 (9)	0.0380 (10)	0.0470 (9)	−0.0089 (7)	−0.0019 (7)	−0.0036 (7)
C7	0.0412 (9)	0.0298 (9)	0.0452 (9)	−0.0037 (7)	−0.0009 (7)	−0.0046 (7)
C8	0.0348 (8)	0.0276 (8)	0.0291 (7)	−0.0009 (6)	0.0049 (6)	−0.0017 (6)
C9	0.0336 (7)	0.0203 (7)	0.0276 (7)	0.0010 (6)	0.0103 (5)	−0.0014 (5)
C10	0.0289 (7)	0.0210 (7)	0.0293 (7)	0.0028 (5)	0.0076 (5)	0.0031 (5)
C11	0.0293 (7)	0.0305 (8)	0.0258 (7)	−0.0002 (6)	0.0101 (5)	−0.0004 (5)
C12	0.0281 (7)	0.0271 (7)	0.0224 (6)	−0.0043 (6)	0.0078 (5)	0.0001 (5)
B1	0.0299 (8)	0.0230 (8)	0.0177 (7)	0.0018 (6)	0.0074 (5)	0.0036 (5)

Geometric parameters (Å, º)

O1—C9	1.4243 (16)	C5—H5B	0.9900
O1—B1	1.4666 (17)	C6—C7	1.518 (2)
O2—C11	1.4177 (15)	C6—H6A	0.9900
O2—B1	1.4713 (17)	C6—H6B	0.9900
N1—C10	1.4868 (16)	C7—C8	1.524 (2)
N1—C12	1.4947 (16)	C7—H7A	0.9900
N1—B1	1.6720 (17)	C7—H7B	0.9900
N1—H1B	0.9300	C8—H8A	0.9900
C1—C2	1.3332 (18)	C8—H8B	0.9900
C1—B1	1.587 (2)	C9—C10	1.5184 (18)
C1—H1A	0.9500	C9—H9A	0.9900
C2—C3	1.4713 (19)	C9—H9B	0.9900
C2—H2A	0.9500	C10—H10A	0.9900
C3—C4	1.3348 (19)	C10—H10B	0.9900
C3—C8	1.5047 (19)	C11—C12	1.5145 (19)
C4—C5	1.502 (2)	C11—H11A	0.9900
C4—H4A	0.9500	C11—H11B	0.9900
C5—C6	1.507 (2)	C12—H12A	0.9900
C5—H5A	0.9900	C12—H12B	0.9900
C9—O1—B1	109.56 (9)	H7A—C7—H7B	108.1
C11—O2—B1	109.48 (9)	C3—C8—C7	112.59 (12)
C10—N1—C12	114.59 (10)	C3—C8—H8A	109.1
C10—N1—B1	103.92 (9)	C7—C8—H8A	109.1
C12—N1—B1	105.04 (9)	C3—C8—H8B	109.1
C10—N1—H1B	111.0	C7—C8—H8B	109.1
C12—N1—H1B	111.0	H8A—C8—H8B	107.8
B1—N1—H1B	111.0	O1—C9—C10	104.77 (10)
C2—C1—B1	124.72 (12)	O1—C9—H9A	110.8
C2—C1—H1A	117.6	C10—C9—H9A	110.8
B1—C1—H1A	117.6	O1—C9—H9B	110.8
C1—C2—C3	128.15 (13)	C10—C9—H9B	110.8
C1—C2—H2A	115.9	H9A—C9—H9B	108.9
C3—C2—H2A	115.9	N1—C10—C9	103.21 (10)
C4—C3—C2	120.05 (13)	N1—C10—H10A	111.1
C4—C3—C8	120.84 (13)	C9—C10—H10A	111.1
C2—C3—C8	119.09 (12)	N1—C10—H10B	111.1
C3—C4—C5	124.93 (15)	C9—C10—H10B	111.1
C3—C4—H4A	117.5	H10A—C10—H10B	109.1
C5—C4—H4A	117.5	O2—C11—C12	105.28 (10)
C4—C5—C6	112.76 (13)	O2—C11—H11A	110.7
C4—C5—H5A	109.0	C12—C11—H11A	110.7
C6—C5—H5A	109.0	O2—C11—H11B	110.7
C4—C5—H5B	109.0	C12—C11—H11B	110.7
C6—C5—H5B	109.0	H11A—C11—H11B	108.8
H5A—C5—H5B	107.8	N1—C12—C11	102.66 (10)
C5—C6—C7	111.40 (13)	N1—C12—H12A	111.2
C5—C6—H6A	109.3	C11—C12—H12A	111.2
C7—C6—H6A	109.3	N1—C12—H12B	111.2
C5—C6—H6B	109.3	C11—C12—H12B	111.2
C7—C6—H6B	109.3	H12A—C12—H12B	109.1
H6A—C6—H6B	108.0	O1—B1—O2	113.23 (11)
C6—C7—C8	110.83 (13)	O1—B1—C1	112.33 (11)
C6—C7—H7A	109.5	O2—B1—C1	114.79 (11)
C8—C7—H7A	109.5	O1—B1—N1	101.66 (10)
C6—C7—H7B	109.5	O2—B1—N1	100.60 (10)
C8—C7—H7B	109.5	C1—B1—N1	112.87 (10)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1B···O1^i	0.93	1.97	2.8581 (13)	158

Symmetry code: (i) x, −y+1/2, z+1/2.