ABSTRACT
For the first time the computed mechanisms for the novel reaction of 2-naphthol with N-methyl-N-phenylhydrazine, leading to 1-amino-2-naphthol (Tang et al., J Am Chem Soc 2008, 130, 5840), have been investigated using the density functional theory. Four distinct possible pathways were evaluated: two amination mechanisms with the attack of NH(2) group respectively at the α-position C1 and ß-position C3 atoms of 2-naphthol (pathways 1 and 2) as well as two rearrangement processes with displacement of the phenolic hydroxyl group followed by the benzidine-like rearrangement at the α-position C1 and ß-position C3 atoms of 2-naphthol, respectively (pathways 3 and 4). Solvent effect has been tested based on the optimized geometries of the stationary points in solution at the B3LYP/PCM/6-31+G(d,p) level of theory with an averaged dielectric constant of binary solvent. Single-point energies of the optimized structures have been calculated using three hybrid density functionals, B3LYP, MPW3LYP, and B3PW91 with the 6-311++G(3df,2p) basis set. Our computed results clearly manifest that pathway 1 (α-amination) has the highest possibility to occur, with the Gibbs free energies being lower by 6 to 20 kcal/mol compared with the other three pathways, which leads to 1-amino-2-naphthol and N-methylaniline as products. It is in excellent agreement with the experimental observation.
Subject(s)
Naphthols/chemistry , Phenylhydrazines/chemistry , Quantum Theory , Amines/chemical synthesis , Amines/chemistry , Molecular Structure , StereoisomerismABSTRACT
The coordination geometry about the Pd centre in the title compound, [Pd(C(40)H(42)N(5))Cl], is approximately square-planar. The CNC pincer-type N-heterocyclic carbene ligand binds to the Pd atom in a tridentate fashion by the amido N atom and the two carbene atoms and generates two six-membered chelate rings, completing the coordination.
ABSTRACT
The coordination geometry of the Pd atom in the title compound, [Pd(SCN)(2)(C(46)H(54)N(4)O(6))], is approximately square-planar. The N-heterocyclic carbene (NHC) metallacrown ether ligand binds to the Pd atom in a trans orientation through the carbene C atoms of the two imidazole rings and generates a 25-membered chelate ring. Two mutually trans S-bound thio-cyanate ligands complete the coordination.
ABSTRACT
In the title compound, C(25)H(35)N(3) (2+)·2Br(-)·H(2)O, the dihedral angles between the imidazole ring and the two outer benzene rings are 80.16â (16) and 69.40â (18)°. The component species are linked by N-Hâ¯Br, O-Hâ¯Br and C-Hâ¯Br hydrogen bonds.
ABSTRACT
In the title compound, C(19)H(22)N(3)O(+)·Br(-), the imidazole ring is approximately coplanar with the pyridine ring [dihedral angle = 0.88â (13)°] and nearly perpendicular to the benzene ring [dihedral angle = 81.70â (13)°]. O-Hâ¯Br and C-Hâ¯Br hydrogen bonding helps to stabilize the crystal structure.
