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Keywords
- Asymmetric Catalysis (1)
- Bisamidines (1)
- Brønsted base (1)
- Diels- Alder reaction (1)
- Organocatalysis (1)
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2-({4-[4-(1H-Benzimidazol-2-yl)phenyl]-1H-1,2,3-triazol-1-yl}methoxy)ethanol
(2012)
- In the title molecule, C18H17N5O2, the dihedral angle between the benzene plane and the benzimidazole plane is 19.8 (1)° and the angle between the benzene plane and the triazole plane is 16.7 (1)°. In the crystal, molecules are connected by O—H[cdots, three dots, centered]N hydrogen bonds, forming zigzag chains along the c-axis direction. The chains are connected by bifurcated N—H[cdots, three dots, centered](N,N) hydrogen bonds into layers parallel to (100). These layers are connected along the a-axis direction by weak C—H[cdots, three dots, centered]O contacts, forming a three-dimensional network.
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N-(2,6-Diisopropylphenyl)formamide toluene 0.33-solvate
(2012)
- The crystal packing of the title compound, C13H19NO·0.33C7H8, shows a channel at [001], which contains grossly disordered toluene solvent molecules. The angle between the benzene ring and the mean plane of the formamide group is 71.1 (1)°. The amide groups of neighbouring molecules are connected by N—H(...)O hydrogen bonds, forming 21 helical chains propagating along [001]. Molecules are also connected by weak intermolecular C—H(...)O hydrogen bonds, forming 61 helices.
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(Acetonitrile-κN)chloridobis[2-(pyridin-2-yl)phenyl-κ2 C 1,N]iridium(III)
(2011)
- The IrIII atom of the title compound, [Ir(C11H8N)2Cl(CH3CN)], displays a distorted octahedral coordination. The pyridyl groups are in trans positions [N—Ir—N = 173.07 (10)°], while the phenyl groups are trans with respect to the acetonitrile and chloride groups [C—Ir—N = 178.13 (11) and C—Ir—Cl = 176.22 (9)°]. The pyridylphenyl groups only show a small deviation from planarity, with the dihedral angle between the planes of the two six-membered rings in each pyridylphenyl group being 5.6 (2) and 5.8 (1)°. The crystal packing shows intermolecular C—H[cdots, three dots, centered]Cl, C—H[cdots, three dots, centered]π(acetonitrile) and C—H[cdots, three dots, centered]π(pyridylphenyl) contacts.
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Biphenyl-4,4'-diyl bis(2,2,5,5-tetramethyl-1-oxyl-3-pyrroline-3-carboxylate)
(2009)
- In the title compound, C30H34N2O6, the complete molecule is generated by a crystallographic 2/m symmetry operation. The 1-oxyl-3-pyrroline-3-carboxylate group lies on a mirror plane. The dihedral angle between the ring planes of the biphenyl fragment is constrained by symmetry to be zero, resulting in rather short intramolecular H...H contact distances of 2.02 Å. In the crystal, molecules are connected along the a-axis direction by very weak intermolecular methyl-phenyl C-H...[pi] interactions. The C-H bond is not directed to the center of the benzene ring, but mainly to one C atom [C-H...C(x - 1, y, z): H...C = 2.91 Å and C-H...C = 143°]. Key indicators: single-crystal X-ray study; T = 169 K; mean σC–C) = 0.002 Å ; R factor = 0.049; wR factor = 0.126; data-to-parameter ratio = 19.8.
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4-Ethynyl-2,2,6,6-tetramethyl-1,2,5,6-tetrahydropyridine N-oxide
(2009)
- The six-membered ring of the title compound, C11H16NO, has a distorted envelope conformation. The piperidine N atom deviates by 0.128 (1) Å from the plane through its three neighbouring atoms. In the crystal structure, molecules are connected by intermolecular Cethynyl-H...O contacts to form chains extending in the [10\overline{1}] direction. Key indicators: single-crystal X-ray study; T = 167 K; mean σ(C–C) = 0.001 Å ; R factor = 0.040; wR factor = 0.112; data-to-parameter ratio = 27.3.
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3-Ethynyl-2,2,5,5-tetramethyl-1-oxyl-3-pyrroline
(2009)
- The five-membered ring of the title compound, C10H14NO, is almost planar [mean deviation from best plane = 0.006 (1) Å]. The N-O bond is in the plane of the five-membered ring. The molecule is positioned about a pseudo-mirror plane at y = 0.375. In the crystal, molecules are connected by intermolecular C-H...O contacts into layers parallel to (010). Key indicators: single-crystal X-ray study; T = 167 K; mean σ(C–C) = 0.002 Å; R factor = 0.062; wR factor = 0.157; data-to-parameter ratio = 27.3.
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C2-symmetric bisamidines : chiral Brønsted bases catalysing the Diels-Alder reaction of anthrones
(2008)
- C2-symmetric bisamidines 8 have been tested as chiral Brønsted bases in the Diels- Alder reaction of anthrones and N-substituted maleimides. High yields of cycloadducts and significant asymmetric inductions up to 76% ee are accessible. The proposed mechanism involves proton transfer between anthrone and bisamidine, association of the resulting ions and finally a cycloaddition step stereoselectively controlled by the chiral ion pair.
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(Z,Z)-1,4-Diiodo-1,4-bis(trimethylsilyl)buta-1,3-diene
(2008)
- The asymmetric unit of the title compound, C10H20I2Si2, contains two half-molecules. Both complete molecules are generated by crystallographic inversion centers located at the mid-points of the central C-C single bonds; the butadiene groups are planar, with a trans conformation about the central C-C bond. The molecules show short intramolecular H...I contacts of 2.89 and 2.92 Å. The crystal packing shows no short intermolecular contacts. Key indicators: single-crystal X-ray study; T = 155 K; mean σ(C–C) = 0.002 Å ; R factor = 0.021; wR factor = 0.059; data-to-parameter ratio = 43.6.
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(Rp)-1-{(R)-(Dimethylamino)[2-(diphenylphosphanyl)phenyl]methyl}-2-(diphenylphosphanyl)ferrocene chloroform solvate
(2008)
- The absolute configuration of the title molecule, [Fe(C5H5)(C38H34NP2)]·CHCl3, is R,Rp. The molecular structure is similar to the structure of the solvent-free compound [Fukuzawa, Yamamoto & Kikuchi (2007). J. Org. Chem. 72, 1514-1517], but some torsion angles about the P-Cphenyl bonds differ by up to 25°. The P atoms and the N atom have a distorted trigonal-pyramidal geometry. The chloroform solvate group donates a C-H...[pi] bond to the central benzene ring and is also involved in six intermolecular C-H...Cl contacts with H...Cl distances between 2.96 and 3.13 Å. Key indicators: single-crystal X-ray study; T = 163 K; mean σ(C–C) = 0.003 Å; R factor = 0.039; wR factor = 0.088; data-to-parameter ratio = 24.2.
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(Sp)-1-Diphenylphosphanyl-2-{(S)-[2-(diphenylphosphanyl)phenyl]hydroxymethyl}ferrocene
(2008)
- The absolute configuration of the title compound, [Fe(C5H5)(C36H29OP2)], is Sp at the ferrocene group and S at the asymmetric C atom. Both P atoms have a trigonal-pyramidal conformation. There is a short intramolecular C-H...P contact with an H...P distance of 2.56 Å. The hydroxy group is involved in an intramolecular O-H...[pi]phenyl interaction. The crystal packing shows five very weak intermolecular C-H...[pi] contacts, with H...Cg distances between 3.26 and 3.39 Å (Cg is the centroid of a phenyl or cyclopentadienyl ring). Key indicators: single-crystal X-ray study; T = 162 K; mean σ(C–C) = 0.004 Å; R factor = 0.038; wR factor = 0.083; data-to-parameter ratio = 22.3.
