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The synthesis of fiveand six-membered oxygen-and nitrogen-containing heterocycles has been regarded as the most fundamental issue in organic chemistry and chemical industry because they are used in producing high-value products. In this study, an efficient, economic, sustainable, and green protocol for multicomponent synthesis has been developed. The one-pot direct Knoevenagel condensation−Michael addition−cyclization sequences for the transformation of aromatic aldehydes, malononitrile, and 4-hydroxycoumarin or phthalhydrazide generate the corresponding dihydropyrano[2,3-c]chromenes and 1Hpyrazolo[1,2-b]phthalazine-5,10-diones over a novel mesoporous metal− organic framework-based supported Cu(II) nanocatalyst

A novel, totally asymmetrical tripodal 2,3',4"-tetraamine ligand, N((CH2)2NH2)((CH2)3NH2)((CH2)4NH2), epb, has been synthesized. In the presence of copper(II) and nickel(II) ions it condenses with 2,6-diacetylpyridine in 1:1 ethanol-water solution, producing some new CR-type complexes with a pendant primary amino group. The X-ray crystal structure of the resulting copper(II) complex, [Cu(3,4(2)-CR)](PF6)2 (1), and two other related complexes, [Cu(2,4(2)-CR)](ClO4)2 (2) and [Cu(3,3(2)-CR)](ClO4)2 (3), are reported. Crystal data: complex 1, monoclinic, P2(1)/n, a = 8.366(3) A, b = 15.549(3) A, c = 20.283(2) A, beta = 98.73(2) degrees, V = 2607.8(11) A3, Z = 4, R1 = 0.0621, wR2 = 0.1615; complex 2, monoclinic, P2(1)/c, a = 7.981(10) A, b = 18.882(3) A, c = 15.185(3) A, beta = 96.40(2) degrees, V = 2275.7(6) A3, Z = 4, R1 = 0.0773, wR2 = 0.1635; complex 3, monoclinic, P2(1)/n, a = 7.8764(10) A, b = 15.361(2) A, c = 19.370(2) A, beta = 100.330(10) degrees, V = 2305.7(5) A3, Z = 4, R1 = 0.0537, wR2 = 0.1397. In all of these, copper atoms are bonded to four nitrogens of a macrocyclic ring and a nitrogen of the pendant arm. The arrangements are slightly distorted square-pyramidal in which the primary amino groups occupy apical positions and have the longest Cu-N distances. For all isomers, copper(II) ions are somewhat above the plane of the imino-pyridine system of the macrocylic ring in the direction of the pendant coordinated primary amino group.

A simple, clean, and highly efficient green protocol has been developed for synthesis of bis(indolyl), di(bis-indolyl), and tris-indolyl methanes by the reaction of indole with aldehydes and ketones in the presence of oxalic acid dihydrate [(CO(2)H)(2).2H(2)O] and N-cetyl-N, N, N-trimethylammonium bromide (CTAB) in water. Also, tri(bis-indolyl) and tetra(bis-indolyl)methanes as new bis(indolyl)methanes were prepared under thermal conditions.

In this research study we designed and synthesized CoII(macrocyclic Schiff base ligand containing 1,4‐diazepane) immobilized on Fe3O4 nanoparticles as a novel, recyclable, and heterogeneous catalyst. The nanomaterial was fully characterized using various techniques such as Fourier‐transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, energy‐dispersiveX‐ray spectroscopy, thermogravimetric analysis, vibrating sample magnetometry, differential reflectance spectroscopy, Brunauere–Emmette–Teller method, inductively coupled plasma, and elemental analysis (CHNS). Then, the catalytic performance was successfully investigated in the multicomponent synthesis of 2‐amino‐4‐aryl‐6‐(phenylsulfanyl)pyridine‐3,5‐dicarbonitrile and 2‐amino‐5,10‐dioxo‐4‐aryl‐5,10‐dihydro‐4H‐benzo[g]chromene‐3‐carbonitrile derivatives. Furthermore, the catalyst was isolated using a simple filtration, and recovery of the nanocatalyst was demonstrated five times without any loss of activity.

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N-Nitrosation chemistry of amines is an important and well-established reaction in organic synthesis. 1 The most general reagent is nitrous acid, generated from sodium nitrite and mineral acid in water or in mixed alchoholwater solvents. 2 Other nitrosating agents, such as Fremy's salt, 3 bis(triphenylphosphine)nitrogen(1+) nitrite, 4 N-haloamides and sodium nitrite under phase-transfer conditions, 5 oxyhyponitrite, 6 dinitrogen tetroxide, 7 solid acids (i.e., oxalic acid dihydrate, 8 inorganic acidic salts 9 and hydrolyzable chloride salts 10 ), and sodium nitrite have also been used. We were interested to find a completely homogeneous reagent for the N-nitrosation of secondary amines, and thus we have investigated a number of different reaction conditions based upon the in situ generation of NO + . In continuing of our studies on the application of NOX, 11 N 2 O 4 , 12 metal nitrate dinitrogen tetroxide complexes. 13 and complexation of transition metals with macrocyclic ethers, 14 we found that 18-Crown-6 gives an ionic complex with N 2 O 4 gas as [NO + ‚Crown‚H(NO 3 ) 2 -] in quantitative yields. In this communication we now report a simple and convenient method using this new reagent for the effective Nnitrosation of secondary amines (1) to their corresponding N-nitroso derivatives (2) under mild conditions. Different types of secondary amines (1) were subjected to the nitrosation reaction in the presence of [NO + ‚Crown‚H(NO 3 ) 2 -] (I) and dry SiO 2 in dichloromethane. The nitrosation reactions were performed under mild conditions at room temperature and take place with quantitative yields (Scheme 1).This present nitrosation reaction can be readily carried out by placing the complex [NO + ‚Crown‚H(NO 3 ) 2 -] (I), amine (1), dry SiO 2 and CH 2 Cl 2 as the solvent in a reaction vessel and efficiently stirring the resulting mixture at room temperature. The reactions were completed after 5 min. The reaction mixture was filtered, and dichloromethane was also removed by water bath (40-50°C) and simple distillation. The highly pure nitrosoamines (2) were obtained by passing the residue through a pad of silica gel.A competitive reaction was performed between dicyclohexylamine (1c) and anisole. It was observed that amine nitrosation occurred exclusively, whereas anisole remained intact in the reaction mixture after 1 h. The nitrosation reaction of diphenylamine shows the chemoselectivity of the method as the N-nitrosodiphenylamine is the only product. This system thus behaves differently from some reported methods 2 so that the nitrosonium ion (NO + ) attacks the nitrogen sites of the secondary amines even where an aromatic moiety is connected directly to the nitrogen atom.Furthermore, the chiral center of L-proline (1h) also remained intact in the course of the reaction so that L-nitrosoproline (2h) was obtained quantitatively. LNitrosoproline (2h) is a precursor of mesoionic moieties in an important class of dipolar heterocyclic compounds with special properties. 15,16 Ghorbani Choghamarani, A.; Taqiannasab, A...