The catalytic performance of NHC-ligated Ru-indenylidene or benzylidene complexes bearing a tricyclohexylphosphine or a pyridine ligand in ring closing metathesis (RCM), cross metathesis, and ring closing enyne metathesis (RCEYM) reactions is compared. While the PCy₃ complexes perform significantly better in RCM and RCEYM reactions than the pyridine complex, all catalysts show similar activity ...

The central pyridine ring of the 2,2':6',2''-terpyridine fragment of the title compound, C(35)H(24)N(4)O(2), forms dihedral angles of 8.3 (2), 10.6 (3) and 39.4 (3)°, respectively, with the two outer pyridine rings and the attached benzene ring. In the crystal, weak C-H⋯O inter-actions link the mol-ecules into chains in [010].

In the crystal structure of the title compound, C(22)H(19)FN(4), the quinoxaline system makes dihedral angles of 32.07 (13) and 69.64 (13)° with the 4-fluoro-phenyl and pyridine rings, respectively. The 4-fluoro-phenyl ring makes a dihedral angle of 71.77 (16)° with the pyridine ring. The crystal structure is stabilized by inter-molecular N-H⋯N hydrogen bonding.

In the crystal structure of the title compound, C(21)H(18)FN(5), the pyridopyrazine ring system forms dihedral angles of 33.27 (7) and 48.69 (9)° with the 4-fluoro-phenyl and pyridine ring, respectively. The dihedral angle of the 4-fluoro-phenyl and pyridine rings is 57.45 (8)°. The crystal packing is characterized by an inter-molecular N-H⋯N hydrogen bond.

In the mol-ecule of the title compound, C(20)H(14)N(2)O, the tetra-hydro-benzo[h]quinoline fused-ring system is buckled owing to the ethyl-ene -CH(2)CH(2)- fragment, the benzene ring and the pyridine ring being twisted by 19.7 (1)°. The 4-substituted aromatic ring is bent away from the pyridine ring by 62.9 (1)° in order to avoid crowding the cyanide substituent. In the crystal, two mol-ecules ...

The Front Cover illustrates how the pyridine ring of antihistamine loratadine can be selectively functionalised at ortho-, meta-, or para-position (each them activated by a thunder). Indeed, selective functionalisation this N-heterocycle is often problematic, thus lighthouse guides chemists through late-stage functionalisations pyridine-containing biomolecules. More information found in Review ...

In the title compound, C20H25NO5, the di-hydro-pyridine ring adopts a flattened boat conformation. The meth-oxy-phenyl ring is almost perpendicular to the mean plane of the pyridine ring [dihedral angle = 88.42 (3)°]. The two carbonyl units adopt a synperiplanar conformation with respect to the double bonds in the di-hydro-pyridine ring. In the crystal, mol-ecules are connected by N-H⋯O hydroge...

In the title compound, C(17)H(10)F(6)N(4)·H(2)O, the pyridine ring is not coplanar with the quinoline ring system; the dihedral angle between the two planes is 21.3 (1)°. One of the trifluoro-methyl group is disordered over two orientations with occupancies of 0.70 (1) and 0.30 (1). The water mol-ecule is disordered over two positions with occupancies of 0.76 (1) and 0.24 (1). In the crystal, t...

In the title complex, [Mn(C22H14N3O2)2]·3H2O, the Mn(II) ion is coordinated by two N,N',O-tridentate 2-(2,2':4',2''-terpyridin-6'-yl-κ(2) N (1),N (1'))benzoate ligands in a distorted cis-MnO2N4 octa-hedral geometry. In one ligand, the dihedral angles between the central pyridine ring, the other bonded pyridine ring, the terminal pyridine ring and the benzene ring are 14.3 (15), 18.3 (18) and 43...

In the title compound, C(29)H(18)ClN(5)·C(2)H(6)O, the dihydro-pyridine ring adopts a strongly flattened envelope conformation, with a maximum deviation of 0.139 (2) Å from its best plane for the Csp(3) atom. The dihedral angles between the dihydro-pyridine ring plane and the two indole rings in positions 2 and 6 are 34.28 (5) and 40.50 (6)°, respectively. In turn, the benzene ring and the dihy...