(±) Methanodibenzodiazocine tethered [C-H]δ+ functional site: Study towards benzoin condensation and Baylis-Hillman reactions

New heterocyclic ring systems consisting of (±) methanodibenzodiazocine and imidazolium/ benzimidazolium salts were synthesized in very good yield. Subsequently, these halide salts were subjected to the anion exchange reaction with KPF6 to yield the corresponding azolium salts in excellent yield. The possible applications of these newly prepared salts were investigated in homogeneous catalysis. Remarkable changes in the catalytic activity were observed by varying the bulkiness of N-substituent at imidazole. Catalytic activity of these newly prepared salts was tested for the benzoin condensation reaction. Exclusive formation of benzoin products were observed in good yield. Similarly, the dimerization of cyclohexen-1-one to Baylis-Hillman type product, 2-(3-oxocyclohexyl)-2-cyclohexen-1-one was studied

(+/-)Methanodibenzodiazocine tethered [C-H](delta+) functional site: Study towards benzoin condensation and Baylis-Hillman reactions

New heterocyclic ring systems consisting of (+/-) methanodibenzodiazocine and imidazolium/ benzimidazolium salts were synthesized in very good yield. Subsequently, these halide salts were subjected to the anion exchange reaction with KPF6 to yield the corresponding azolium salts in excellent yield. The possible applications of these newly prepared salts were investigated in homogeneous catalysis. Remarkable changes in the catalytic activity were observed by varying the bulkiness of N-substituent at imidazole. Catalytic activity of these newly prepared salts was tested for the benzoin condensation reaction. Exclusive formation of benzoin products were observed in good yield. Similarly, the dimerization of cyclohexen-1-one to Baylis-Hillman type product, 2-(3-oxocyclohexyl)-2-cyclohexen-1-one was studied

Cationic zinc (II) dimers and one dimensional coordination polymer from ionic carboxylic acid

A rare example of chelating two tetra cationic paddle-wheel zinc dimers were synthesized from the reaction between flexible imidazolium carboxylate (L H 2 B r 2 ) and corresponding zinc precursors. A zinc coordination polymer was synthesised by treating in situ generation of 2 in the presence of 4,4'-bipyridine. These new molecules, dimers and polymer, were characterized by FT-IR, NMR, UV-vis, fluorescent and single crystal X-ray diffraction techniques. Zinc polymer is the first example of 1D coordination polymer constructed by tetra cationic zinc dimer as a secondary building unit in coordination polymer

Linear Cu(I) chalcogenones: synthesis and application in borylation of unsymmetrical alkynes

The syntheses and structures of copper(I) chalcogenone complexes are described. The homoleptic mononuclear copper(I) complexes [(IPrvE)(2)Cu]ClO4, IPr=E, 1,3-bis(2,6-diisopropylphenyl)imidazoline-2-thione (1) and 1,3-bis(2,6-diisopropylphenyl)imidazoline-2-selone (2); [(IMes=E)(2)Cu]ClO4, IMes=E, 1,3-bis(2,4,6-trimethylphenyl)imidazole-2-thione (3) and 1,3-bis(2,4,6-trimethylphenyl)imidazole-2-selone(4); [(IPr=E)(2)Cu]BF4, E = S (5); E = Se (6) and [(IMes=E)(2)Cu]BF4, E = S (7); E = Se (8) are formed from the reduction of copper(II) to copper(I) with the corresponding imidazoline-2-chalcogenones. X-ray structure analyses of seven compounds (1-3 and 5-8) show that the copper(I) ion is in a perfect linear coordination, while 4 is in quasi-linear geometry. Molecules 2, 4, 6 and 8 are the first structurally characterized homoleptic copper(I) selone complexes. The optical and thermal properties of imidazoline-2-chalcogenones and their copper(I) derivatives are investigated. These complexes are able to act as catalysts in regioselective borylation of numerous unsymmetrical alkynes, yielding synthetically useful vinylboronates. Among catalysts 1-8, catalyst 4 is highly selective towards the regioselective boron addition of 1-phenyl-1- propyne

Thermal, optical and structural properties of disulfide and diselenide salts with weakly associated anions

The imidazole disulfide and diselenide dicataions were conveniently isolated for the first time by treating imidazole thione or imidazole selone with bismuth(III) triflate or copper perchlorate hexa-hydrate in very good yield. These new salts were characterized by elemental analysis, FT-IR, solid state UV-vis, thermogravimetric analysis and single crystal X-ray diffraction techniques. Interesting thermal properties and unusual bonding situations were observed for these dichalcogenide salts

Semi-rigid imidazolium carboxylate controlled structural topologies in zwitterionic coordination networks

The zwitterionic coordination networks [L2Mn(H2O)2]∞ (1), [L2Co(H2O)2]∞ (2), [L2Ni(H2O)4]∞ (3), [L2Cu]∞ (4), [L2Zn(H2O)2]∞ (5) and [L3Cd2(Br)2]∞ (6) were synthesized from the reaction between the semi-rigid imidazolium carboxylate spacer LH2+Br− and the corresponding metal nitrates in DMF/H2O at 130 °C. The solid state structures of 1–6 were confirmed by the single-crystal X-ray diffraction technique. The molecules 1, 2 and 5 are isostructural one-dimensional coordination polymers. 3 was isolated as a monomer and the monomers are associated into a three dimensional fashion through O–H⋯O hydrogen bonds, while 4 was isolated as a 1D coordination polymer. Compound 6 was constructed as a two-dimensional coordination framework with a rare [Cd2(μ2-Br)2] core. The purity of 1–6 in the bulk was confirmed by the powder X-ray diffraction technique. Furthermore the electronic properties of 1–6 were studied using UV–Vis spectroscopy and the thermal stabilities of 1–6 were confirmed by TGA

Coumarin-Picolinohydrazone derived Schiff base as fluorescent sensor(OFF-ON) for detection of Al3+ ion: Synthesis, Spectral and theoretical studies

New coumarin based Schiff base (7MIZ) was synthesized and characterized by various spectral techniques and the true nature was established by X-ray single crystal studies. The probe (7MIZ) acted as fluorescent sensor for detection of Al3+ ion among different metal ions (chloride salts) with high selectively. There was a drastic enhancement in the emission intensity at 482 nm showed fluorescence turn ‘ON’ behavior of the probe when it interacted with Al3+ ion which may be due to CHEF (chelation enhanced fluorescence) effect that inhibited the PET (photo-induced electron transfer) mechanism. Further, Job's plot, binding constant value, LOD value, DFT studies established the interaction between probe (7MIZ) andAl3+ ion and MTT assay studies were carried out for the probe (7MIZ) and Al3+ ion in Breast cancer cell line (MDA-MB-231)

Bidentate Selones Supported Bismuth(III) Catalysts for O-Acylative Cleavage of Cyclic Ethers

An efficient noble methodology, to synthesise a series of novel dibenzimidazole based selone compounds with high yield has been demonstrated here by using NaH route at room temperature. On the basis of experimental data here a method has been adopted for the evaluation of a series of selone compounds by which σ-donor and π-acceptor components of NHC moieties has been investigated. Moreover, a mild, quantitative, regioselective O-acylative cleavage of cyclic ethers was established by in situ generation of bidentate selones supported bismuth(III) catalysts. In particular, with increasing σ-donation property as well as increasing chelation capability of selone ligands towards bismuth(III) activity of catalyst towards O-acylative cleavage of 2-methyl tetrahydrofuran also increases

Antithyroid Drug Analogues Synthesis and Structural Study

Thiourea-based Antithyroid drugs propylthiouracil (PTU), methimazole (MMI), and carbimazole (CBZ) may block the thyroid hormone biosynthesis whereas selenourea containing drugs reduce H2O2, which is required for oxidation of catalyst leads to decrease in thyroid hormone production. Thus, new tris organo selone derivatives 3,3',3''-((2,4,6-trimethylbenzene-1,3,5-triyl)tris(methylene))tris(1-(2,6-alkyl/aryl)-1H-imidazole-2(3H)-selenone) 4a-4f have been synthesized for the first time by the reaction of 1,1',1''-((2,4,6-trimethylbenzene-1,3,5-triyl)tris(methylene))tris(3-alkyl/aryl-1H-imidazol-3-ium)bromide (1eq.), potassium carbonate (6eq.) and selenium powder (6eq.). These new molecules have been characterized by multinuclear NMR (1H NMR, 13C NMR, DEPT), FT-IR and UV-vis. studies. The 1H and 13C chemical shifts have been confirmed on the basis of correlation spectra e.g HSQC, HMBC. Photophysical properties have been derived from UV−vis. The molecular structures of 4a, 4b, 4c, 4d and 4e have been determined by X-ray crystallography, which suggests that these compounds exist as zwitterions in which the selenium atom carries a large negative charge which enhances the nucleophilic activity of compound

Discrete monomeric bismuth(III) triflate trapped by bis-selenone

A series of imidazolium salts were made from the reaction between alkyl or aralkyl dihalide and 1-alkyl imidazole. These were treated with Selenium metal powder in the presence of K2CO3 as base to generate insitu carbene to make imidazoselones. The product formation was unambiguously confirmed by NMR (1HNMR, 13C NMR, DEPT and HSQC, HMBC correlations), FTIR and UV-vis studies. In addition the solid-state structure also proved by single crystal X-ray diffraction technique. These newly prepared imidazoselones were subjected towards bismuth(III)triflate to get tetra selenium coordinated bismuth(III)triflate complex which was unambiguously confirmed by single crystal X-ray diffraction technique. Further it was characterized by NMR (1HNMR, 13C NMR, DEPT and 19F NMR), FT-IR, UVvis and powder X-ray diffraction technique. The thermal stability of the bismuth(III)triflate complex was carried out by TGA