27832-35-5

Upstream product

• 574-96-9 1-hydroxy-2-naphthaldehyde 
• 62-53-3 aniline 
• 98-95-3 nitrobenzene 
• 50493-08-8 2-formyl-1-tetralone 

Downstream Products

• 123589-15-1 bis(1-hydroxy-2-naphthylmethylideneanilinato)palladium(II) 

Relevant academic research and scientific papers

Synthesis, Structure, and Catalytic Hydrogenation Activity of [NO]-Chelate Half-Sandwich Iridium Complexes with Schiff Base Ligands

A series of N,O-coordinate iridium(III) complexes with a half-sandwich motif bearing Schiff base ligands for catalytic hydrogenation of nitro and carbonyl substrates have been synthesized. All iridium complexes showed efficient catalytic activity for the hydrogenation of ketones, aldehydes, and nitro-containing compounds using clean H2 as reducing reagent. The iridium catalyst displayed the highest TON values of 960 and 950 in the hydrogenation of carbonyl and nitro substrates, respectively. Various types of substrates with different substituted groups afforded corresponding products in excellent yields. All N,O-coordinate iridium(III) complexes 1-4 were well characterized by IR, NMR, HRMS, and elemental analysis. The molecular structure of complex 1 was further characterized by single-crystal X-ray determination.

Influence of bond fixation in benzo-annulated N-salicylideneanilines and their ortho-C(=O)X derivatives (X = CH3, NH2, OCH 3) on tautomeric equilibria in solution

(Chemical Equation Presented) 1H, 13C, and 15N NMR spectra show that an ortho-C(=O)X group present in the molecules of N-salicylideneanthranilamide (X = NH2), methyl N-salicylideneanthranilate (X = OCH3), N-salicylidene-o- aminoacetophenone (X = CH3), and their benzo analogues have only a minor effect on the tautomeric OH/NH-equilibrium in solution. Only two of three possible tautomers were detected Lability of the absent form was proved by theoretical calculations. Calculated energies show that the enolimino form (OH) is less stable than the enaminone (NH) form only for dibenzo-annulated N-salicylideneanilines. The population of each species in the tautomeric mixture was found to be inversely proportional to its energy. Application of the geometry-based aromaticity index HOMA shows that the effectiveness of the π-electron delocalization in different rings in the molecule depends mostly on the position of benzoannulation. Both the NH...O and N...HO hydrogen bonds present in the NH and OH tautomers respectively, increase the aromaticity of the quasirings H-O-C=C-C=N and O=C-C=C-N-H and decrease the aromatic character of the fused benzene ring. These results seem to be reliable when N-salicylideneanilines studied are compared with naphthalene and their benzo-annulated derivatives i.e., phenanthrene, anthracene, and triphenylene. An analysis of the effectiveness of π-electron delocalization confirms that in all cases studied, the OH form is more stable. Although the HOMA values and calculated energies are not a criterion that allows determination of the dominating tautomer, both of these parameters correctly show the effect of changes in the molecular topology on tautomeric preferences.

Tautomerism in hydroxynaphthaldehyde anils and azo analogues: A combined experimental and computational study

The enol imine ? enaminone tautomerization constants, K T, and thermodynamic parameters, ΔHT and ΔST, of 1-hydroxy-2-naphthaldehyde Schiff bases are determined by UV/vis spectroscopy. Polar solvents shift the equilibrium toward the quinone form (for the unsubstituted derivative 1c, KT = 0.20 (cyclohexane) and KT = 1.49 (ethanol)). Both donor (MeO, NMe2) and acceptor (CN, NO2) substituents lead to a decreased KT independent of solvent polarity. In apolar solvents, for all derivatives 1a-1e, the enol imine ? enaminone equilibria are endergonic but exothermic. Linear solvation energy relationships allow extrapolation of ΔG T to the gas phase. Density functional theory calculations (B3LYP/6-311+G**) yield good agreement with these extrapolated ΔGT values. Solvent effects on le are also successfully reproduced by the calculations. Geometric (0...N distance) and energetic criteria (conformer energy differences, homodesmotic reactions) establish the importance of intramolecular hydrogen bonding for the tautomerism of these compounds. The results obtained for 1a-1e are compared with tautomeric properties of the isomeric naphthaldehyde anils 2-4, the monocyclic analogues 5 and 6, the corresponding azo derivatives 7-9, and the N-alkyl derivative 10.