2,2′-{[(2,2′-Dieth­oxy-1,1′-binaphthalene-6,6′-di­yl)bis­(4,1-phenyl­ene)]bis­(methan­ylyl­idene)}dimalononitrile

Shikun Chen

doi:10.1107/S1600536812037282

. 2012 Sep 5;68(Pt 10):o2852. doi: 10.1107/S1600536812037282

2,2′-{[(2,2′-Diethoxy-1,1′-binaphthalene-6,6′-diyl)bis(4,1-phenylene)]bis(methanylylidene)}dimalononitrile

Shikun Chen ^a,^*

PMCID: PMC3470211 PMID: 23125655

Abstract

The title compound, C₄₄H₃₀N₄O₂, was prepared from 6,6′-dibromo-2,2′-diethoxy-1,1′-binaphthalene through a coupling reaction with 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzaldehyde followed by a Knoevenagel reaction with malononitrile. The dihedral angle between the symmetry-related naphthalene ring systems is 68.82 (8)° while the dihedral angle between the the naphthalene ring system and the adjacent benzene ring is 16.92 (7)°. Four symmetry-independent molecules which are linked by intermolecular C—H⋯π interaction generate the packing motif in the crystal structure. One of the CN groups is disordered over two sets of sites in a 0.60 (2):0.40 (2) ratio.

Related literature

For applications of 6,6′-dibromo-[1,1′-binaphthalene]-2,2′-diol and its derivatives in asymmetric synthesis, see: Hu et al. (1996 ▶); Lou et al. (2006 ▶); Brunel (2006 ▶). For standard bond lengths, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C₄₄H₃₀N₄O₂
M _r = 646.72
Tetragonal,
a = 8.4556 (12) Å
c = 46.991 (9) Å
V = 3359.7 (10) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 173 K
0.24 × 0.15 × 0.08 mm

Data collection

Rigaku MM007HF diffractometer with Saturn724+ CCD detector
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2008 ▶) T _min = 0.789, T _max = 1.000
11840 measured reflections
1901 independent reflections
1825 reflections with I > 2σ(I)
R _int = 0.043

Refinement

R[F ² > 2σ(F ²)] = 0.043
wR(F ²) = 0.095
S = 1.15
1901 reflections
246 parameters
40 restraints
H-atom parameters constrained
Δρ_max = 0.17 e Å⁻³
Δρ_min = −0.14 e Å⁻³

Data collection: CrystalClear (Rigaku/MSC, 2008 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: Mercury (Macrae et al., 2006 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812037282/qm2082sup1.cif

e-68-o2852-sup1.cif^{(20.4KB, cif)}

Supplementary material file. DOI: 10.1107/S1600536812037282/qm2082Isup2.mol

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812037282/qm2082Isup3.hkl

e-68-o2852-Isup3.hkl^{(93.7KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812037282/qm2082Isup4.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

Cg2 and Cg3 are the centroids of the C11-C16 and C14/C15/C17–C20 rings, respectively.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C4—H4⋯Cg3ⁱ	0.95	2.90	3.710 (3)	144
C10—H10⋯Cg2ⁱ	0.95	2.50	3.363 (3)	150
C22—H22C⋯Cg2ⁱⁱ	0.98	2.94	3.769 (3)	143

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

This project was supported by the Natural Science Foundation of Anhui Province (KJ2011Z340).

supplementary crystallographic information

Comment

Chiral compounds especially when used as chiral ligands are particularly important in asymmetric synthesis. 6,6'-dibromo-[1,1'-binaphthalene]-2,2'-diol and its derivatives have received considerable attention in the literature. They are attractive from several points of view in application (Hu et al., 1996; Lou et al., 2006; Brunel, 2006). As part of our search for new 6,6'-dibromo-[1,1'-binaphthalene]-2,2'-diol compounds, we synthesized the title compound (I), whose X-ray crystal structure is reported herein. No classical inter- or intramolecular hydrogen bonds were found in the structure. Bond lengths (Allen et al., 1987) and angles are within normal ranges. The angle between the planes of the naphthalene rings is 68.82 °.

Experimental

6,6'-dibromo-2,2'-diethoxy-1,1'-binaphthalene (1 g, 2 mmol) in dry THF (45 ml) was treated with 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzaldehyde (1 g, 4.3 mmol) through a coupling reaction to give 4,4'-(2,2'-diethoxy-[1,1'-binaphthalene]-6,6'-diyl)dibenzaldehyde which then reacted with malononitrile to give the title compound as a yellow solid in 83% yield (2 steps). Single crystals of the title compound suitable for X-ray diffraction were obtained by slow evaporation of CH\2Cl\2/n-hexane solution over a period of several days.