Journal of Chemical Research

The difunctional distannoxanes, XR₂SnOSnR₂X, can be prepared by a number of different routes, and frequently turn up unexpectedly in reactions involving organotin compounds. They show a variety of (usually dimeric) structures, and are mild but effective catalysts for a variety of polar organic reactions. This article gives an overview of their chemistry.

The oxidation of several aldo- and keto-phenylhydrazones by [bis(trifluoroacetoxy)iodo]benzene (TFAIB), in aqueous acetic acid leads to the regeneration of the parent carbonyl compounds. The reaction exhibits a first order dependence on both the phenylhydrazone and TFIAB. The oxidation of ketoximes is slower than that of aldoximes. The oxidation of aliphatic phenylhydrazones correlates well in terms of Pavelich–Taft dual substituent-parameter equation. The low positive value of the polar reaction constant indicates a nucleophilic attack by TFIAB on the carbonyl carbon. The reaction is subject to steric hindrance by the alkyl group. A mechanism involving the formation of a cyclic activated complex in the rate-determining step is proposed.

Single crystal X-ray structures of 4-phenyl sulfonyl 2-azetidinone 1, a 1:2 conglomerate of the corresponding 3-methyl (trans) and 3,3-dimethyl derivatives 2A and 2B/2C respectively and 3-acetoxymethyl 1,4-diphenyl 2-azetidinone 3 revealed interesting variation in crystal packing dictated by H-bonding and hydrophobic interactions which may be responsible for molecular recognition in β-lactams.

In an efficient two step synthesis of substituted 8-aryloxy/arylthio-16H-dinaphtho[2,1-d:1′,2′-g][1,3,2] dioxaphosphocin 8-sulfides, dimethylaminopyridine (DMAP) catalyses the preparation of the intermediate monochloride 3 from bis-(2-hydroxy-1-naphthyl)methane (1) and thiophosphoryl chloride. Displacement of the chlorine in 3 with substituted sodium phenoxides or thiophenoxides proceeds nearly quantitatively in toluenetetrahydrofuran at room temperature.

Pyrazolo[3,4-d]pyrrolo[2,3-b]pyridine derivatives (6a–f) were obtained by oxidation of tosylhydrazones of 2-allylamino-5-methoxypyrrole-3-carbaldehydes (3a–f) with lead tetraacetate. The nitrilimine intermediates (5a–f) underwent intramolecular 1,3-dipolar cycloaddition to yield the tricyclic heterocycles 6a–f in good yields.

The recyclable room temperature ionic liquid [bmim]PF₆, namely l-butyl-3-methyl-imidazolium hexafluorophosphate, is used as an alternative solvent to dipolar aprotic solvents for the synthesis of aryl allyl ether by the Williamson method.

The convenient synthesis of seven dinorcholane and 5β-cholane derivatives, 3β-acetoxy-23,24-dinorchol-5-en-22-oyl methoxy anhydride (2), 3β-acetoxy-23,24-dinorchol-5-en-22-oyl chloride (3), 3β-acetoxy-23,24-dinorchol-5-en-22-ol (4), 3α-acetoxy-5β-cholan-24-oic acid (6), 3α-acetoxy-5β-cholan-24-oic acid ethyl ester (7), 3-oxo-5β-cholan-24-oic acid (8) and 3-oxo-5β-cholan-24-oic acid ethyl ester (9) have been described. Full spectroscopic data for these compounds are presented.

Alkenes on treatment with iodine and cadmium acetate in acetic acid give α-iodoacetates in high yields. The reaction is facile and α-iodoacetates are obtained from both acyclic and cyclic alkenes within 5–30 min.

Liquid-phase synthesis of isoxazoles and isoxazolines through a 1,3-dipolar of nitrile oxides is described. Soluble polymer-supported nitrile oxides generated in situ react with dipolarophiles to afford isoxazoles and isoxazolines in good yields and purity.

A new stilbene dimer, andalasin B, was isolated from the root trunk of Morus macroura Miq., together with three known compounds, andalasin A, lunularin, oxyresveratrol, and β-resorcylaldehyde.

The treatment of 1-benzyl-, or 1-methyl-6-chlorouracil (1a,b) with nucleophilic primary amines followed by nitrosation, reduction, formylation and dehydro-cyclisation lead to xanthines 5 and 7. While, the treatment of uracil 8 with aromatic aldehydes 9a–f leads to the formation of dipyrimidinopyridines 10a–f, reaction with formalin and primary amines gives pyrimidopyrimidines 11a–d via double Michael reactions.

The N-alkylation of benzotriazole with alkyl halides proceeds efficiently in the presence of potassium hydroxide in ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF₄]).

Indenoquinoxaline-11-one derivatives react with proline and N-aryl maleimides via decarboxylative azomethine ylide formation and subsequent 1,3-dipolar cycloaddition involving an exo- transition state to give new heterocyclic adducts in 71–94% yields.

Reaction of V^IVO(acac)₂ (where Hacac = acetylacetone) with 2-hydroxybenzylalcohol (H₂L) produces [V^VO(L)(acac) (H₂O)], 1 but the above reaction mixture produces [V^VO(L)(hq)(CH₃OH)], 2 and [V^IVO(HL)(pa)(CH₃OH)], 3 in presence of 8-hydroxyquinoline(Hhq) and picolinic acid(Hpa), respectively.

1-Aryl-2-bromo-3,3-difluorocyclopropanes were prepared from the reaction of 2′,2′-difluorostyrene and dibromocarbene instead of from 1-aryl-2-haloacetylenes and difluorocarbene. These results are rationalised by the energy gap between HOMO_(styrene), HOMO_(acetylene) and LUMO_(CX2). The title compounds were converted to methyl arylpropynoate in MeOH solution in quantitative yield.

Three-component condensation of substituted Meldrum's acids with methyl ketones and aminomethylating agent in present of carboxylic anhydride, such as acetic anhydride, gives 5-(3-oxoalkyl)Meldrum's acids.

Ab initio calculations have been performed for H₃⁺ at the Restricted–Hartree–Fock, RHF/cc-pVQZ, level of calculations. The electron density function [Rho(r)] of this simple classical ring system was analysed using AIM theory. Our results showed the nature of the bonds and the quantum mechanical structure of H₃⁺. This analysis resulted in a thoroughly different bond scheme and structure in comparison to what is deduced from the classical view and the previous AIM analysis. The Rho(r) of the H₂ molecule was also analysed by the same manner for comparison.

A variety of polysubstituted thiophenes have been prepared via a solvent-free one-pot microwave assisted Gewald reaction using poly (ethylene glycol) as a soluble polymer support.

The effect of replacing a hydroxyl group by a methoxyl group on the microbiological hydroxylation of some steroids by the fungus, Cephalosporium aphidicola, has been examined.

Kieselguhr supported copper chloride catalyses the oxidation of thiols to disulfides in the presence of oxygen or air.

In this paper, a series of N-aryl substituted toluenesulfamides were synthesised by grinding under solvent-free conditions at room temperature. The yields were excellent (88%–97%), and the process is simple.

In the present study, 4-thiazolidinones have been assembled by HBTU mediated three-component reaction of amine, aldehyde and mercapto acid derivatives at room temperature. The final compounds are obtained in excellent yields within 30 minutes.

Condensation of 2-carbamoylmethyl-1-methyl-3,4-dihydroisoquinolinium chloride with nicotinaldehyde in the presence of a catalytic amount of piperidine affords trans-3-carbamoyl-2-(3-pyridyl)-1,2,5,6-tetrahydro-3H-pyrrolo[2,1-a]isoquinolinium chloride.0

The crystal structure of 3β,22-dihydroxy-23,24-dinorchol-4-ene, previously synthesised from 3-oxo-23,24-dinorchol-4-ene-22-al, has been determined by X-ray crystallography.

The syntheses of three new thiamacrocycles 5, 6 and 7 including the 1,10-phenanthroline unit are described and show high selectivity for Pb²⁺ and Ag⁺.