15 research outputs found
Racemic tricarbonyl[(4a,5,6,7,8,8a-η)-2-phenyl-3,4-dihydro-2H-1-benzopyran]chromium(0)
The title compound, [Cr(C15H14O)(CO)3], displays a distorted envelope configuration of the dihydropyrane ring. The dihedral angle between the phenyl and phenylene rings is 50.63 (4)°. The Cr0 atom is coordinated by three CO groups and the phenylene ring of the flavan ligand in an η6 mode, with a common arene-to-metal distanc
Racemic tricarbonyl(η6-7-methoxyflavan)chromium(0)
In the title compound [systematic name: tricarbonyl(η6-7-methoxy-2-phenyl-3,4-dihydro-2H-1-benzopyran)chromium(0)], [Cr(C16H16O2)(CO)3], the Cr(CO)3 unit is coordinated by the phenylene ring of the flavan ligand, exhibiting a three-legged piano-stool conformation, with a point to plane distance of 1.750 (1) Å. The phenyl ring is twisted away from the fused ring system by 36.49 (5)° (r.m.s. deviation = 0.027 Å; fitted atoms are the C6 ring and the attached fused-ring C and O atoms). The dihydropyran ring displays a distorted envelope configuration by displacement of the phenyl-bearing and the adjacent ring C atoms from the fused-ring system plane by 0.356 (2) and 0.402 (2) Å, respectively
Tricarbonyl(η6-flavone)chromium(0)
In the title compound, [Cr(C15H10O2)(CO)3], the Cr(CO)3 unit exhibits a three-legged piano-stool conformation. The chromium metal centre is coordinated by the phenyl ring of the flavone ligand [Cr—(phenyl centroid) distance = 1.709 (1) Å]. The ligand is approximately planar, the dihedral angles between the γ-pyrone ring and the phenyl ring and between the γ-pyrone and the phenylene ring being 2.91 (5) and 3.90 (5)°, respectively. The molecular packing shows π–π stacking between the flavone ligands of neighbouring molecules
2′,3,4,4′,5-Pentamethoxychalcone
In the title chalcone [systemetic name 1-(2,4-dimethoxyphenyl)-3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one], C20H22O6, the dihedral angle between the plane of the two benzene rings is 7.03 (4)° with all but one of the methoxy groups essentially co-planar with these rings [C—C—O—C torsion angles = −76.1 (2), −0.7 (3), 1.8 (3), −6.2 (3), 2.0 (3)°]. An intramolecular C—H⋯O interaction occurs. The crystal packing is stabilized by weak intermolecular C—H⋯O hydrogen bonds
4,5-Bis(2,4-di-tert-butylphenoxy)phthalonitrile
In the title compound, C36H44N2O2, the dihedral angles between the phthalonitrile ring and the two di-tert-butylbenzene rings are 68.134 (8) and 70.637 (11)°. The two nitrile groups are almost coplanar with the phthalonitrile ring except for one of the N atoms which deviates from the plane by 0.125 (4) Å. One of the tert-butyl groups is disordered over two orientations, with refined occupancies of 0.814 (6) and 0.186 (6). Intramolecular C—H⋯O interactions stabilize the molecular structure. The crystal packing is stabilized by intermolecular C—H⋯N interactions
2′,3,4,4′-Tetramethoxychalcone
In the title compound [systematic name: 1-(2,4-dimethoxyphenyl)-3-(3,4-dimethoxyphenyl)prop-2-en-1-one], C19H20O5, the dihedral angle between the benzene rings is 26.88 (5)°. One of the methoxy groups is twisted slightly away from the plane [C—O—C—C torsion angle = −12.8 (3)°] while the others are almost co-planer [C—O—C—C torsion angles = −3.2 (3), 2.6 (3) and −3.6 (3)°]. The crystal packing is stabilized by intermolecular C—H⋯O interactions. A weak intramolecular C—H⋯O interaction occurs
Tricarbonyl(ŋ6-4′,7-dimethoxyiso-flavone) chromium(0)
The metal atom of the Cr(CO)3 unit of the title compound, [Cr(C17H14O4)(CO)3], is coordinated to the methoxyphenyl ring of the isoflavone ligand; the Cr(CO)3 unit exhibits a three-legged piano-stool conformation. The aromatic ring of the methoxyphenyl group is twisted by 42.49 (9)° with respect to the -pyrone ring. In the fused-ring, the dihedral angle between the phenylene and -pyrone rings is 3.08 (13)°.This paper includes supplementary materials
Regioselective Hydrogenation of alpha,beta-Unsaturated Ketones over Wilkinson's Catalyst
The reactivity of a variety of alpha,beta-unsaturated acyclic and cyclic ketones towards regioselective hydrogenation in the presence of Wilkinson's catalyst was determined. Hydrogenation of sterically hindered alpha,beta-unsaturated ketones proceeded at inefficient rates, if at all.</p