Synthesis of Novel Chiral Thioether Ligands Containing Imidazole Rings Based on Natural Amino Acids

Dibromido[N-(1-diethylamino-1-oxo-3-phenylpropan-2-yl)-N′-(pyridin-2-yl)imidazol-2-ylidene]palladium(II) dichloromethane monosolvate

In the molecule of the title N,N′-disubstituted imidazol-2-ylidene palladium(II) complex, [PdBr2(C21H24N4O)]·CH2Cl2, the palladium(II) atom adopts a slightly distorted square-planar coordination (r.m.s. deviation = 0.0145 Å), and the five-membered chelate ring is almost planar [maximum displacement = 0.015 (8) Å]. The molecular conformation is enforced by intramolecular C—H...Br hydrogen bonds. In the crystal, complex molecules and dichloromethane molecules are linked into a three-dimensional network by C—H...O and C—H...Br hydrogen bonds.

Chelating palladium complexes containing pyridine/pyrimidine hydroxyalkyl di-functionalized N-heterocyclic carbenes: synthesis, structure, and catalytic activity towards C–H activation

Chelating palladium complexes containing pyridine/pyrimidine hydroxyalkyl di-functionalized NHCs were synthesized, characterized and tested for C–H activation of (benzo)oxazoles.

2-[2-(2-Nitro-phen-yl)-4,5-diphenyl-1H-imidazol-1-yl]-3-phenyl-propan-1-ol

In the title compound, C30H25N3O3, the central imidazole ring forms dihedral angles of 77.34 (6), 12.56 (6) and 87.04 (6)°, respectively, with the o-nitro-benzene ring and the phenyl substituents in the 5- and 4-positions. The mol-ecular conformation is stabilized by weak intra-molecular C-H⋯π inter-actions. In the crystal, mol-ecules are linked by O-H⋯N hydrogen bonds, forming chains running parallel to the b-axis direction.

(S)-4,5-Diphenyl-1-[1-phenyl-3-(phenylsulfanyl)propan-2-yl]-2-(thiophen-2-yl)-1H-imidazole

In the title compound, C₃₄H₂₈N₂S₂, the central imidazole ring (r.m.s. deviation = 0.0015 Å) forms dihedral angles of 55.7 (3), 17.94 (11) and 86.27 (11)°, respectively, with the mean planes of the attached thienyl and two phenyl substituents. The thienyl ring shows ring-flip disorder [occupancy ratio = 0.647 (2):0.353 (2)]. The chiral centre maintains the S configuration of the l-phenyl­alaninol starting material. Intra- and inter­molecular C—H⋯S hydrogen bonds involving the disordered thienyl ring are observed.

2-[2-(5-Bromothiophen-2-yl)-4,5-diphenyl-1H-imidazol-1-yl]-3-phenylpropan-1-ol

In the title compound, C₂₈H₂₃BrN₂OS, the dihedral angles formed by the imidazole ring with the 5-bromo­thio­phenyl and phenyl rings are 76.90 (8), 34.02 (10) and 80.93 (11)°, respectively. The chiral centre maintains the S configuration of the l-phenyl­alaninol starting material. In the crystal, mol­ecules are linked by O—H⋯N hydrogen bonds, forming chains running parallel to the a-axis direction.

1-[(2S)-1-Chloro-3-phenylpropan-2-yl]-2,4,5-triphenyl-1H-imidazole

In the title compound, C₃₀H₂₅ClN₂, the chiral center maintains the S configuration of the stating l-phenyl­alaninol. The two phenyl groups closest to the substituted N atom adopt an almost perpendicular orientation relative to the central imidazole ring, with dihedral angles of 88.9 (4) and 84.7 (3)°. The third phenyl group is nearly coplanar with it, making a dihedral angle of 11.0 (5)°.

2-(4,5-Diphenyl-2-p-tolyl-1H-imidazol-1-yl)-3-phenylpropan-1-ol

In the title compound, C₃₁H₂₈N₂O, the dihedral angles formed by the imidazole ring with the three aryl substituents are 18.52 (8) and 85.56 (7) and 85.57 (7)°, respectively. In the crystal, mol­ecules are linked by O—H⋯N and C—H⋯O hydrogen bonds into chains parallel to the a axis.