It is known that phosphinic acids do not undergo direct esterification under conventional conditions. However, the reaction may take place on microwave irradiation. 1-Hydroxy-3-phospholene 1-oxides, 1-hydroxy-phospholane 1-oxides, and a 1-hydroxy-1,2,3,4,5,6-hexahydrophosphinine 1-oxide were esterified with n-pentanol, i-pentanol, n-octanol, and i-octanol(2-ethylhexanol). The phosphinates prepared in 50%–94% yield are all new compounds, and a number of them are useful intermediates.

The mechanism of the reaction of tributyl[(trimethylsilyl)methylene]phosphorane with benzaldehyde and its p-substituted analogues has been examined. It has been found that the electronic nature of the p-substituents in aromatic aldehydes strongly influences the stereochemical and kinetic outcome of the Peterson olefination whereas temperature substantially affects their Hammett correlation. This indicates that the Peterson olefination is a multistep reaction involving the formation of at least an oxyanion/betaine and a carbanion as intermediates. In turn, moderate Z-selectivity might be the result of “steric approach intermediate control”; however, E-selectivity seems to result from the silicon–oxygen interaction and interactions of steric substituents in competing erythro- and threo-betaines.

It has been shown that the derivatives of diethyl 5-amino-2-phthalimidoalkyl-1,3-oxazol-4-ylphosphonates can be employed in the synthesis of phosphorylated peptidomimetics containing the phosphonoglycine residue. The reaction of diethyl 5-alkylamino-2-aminoalkyl-1,3-oxazol-4-ylphosphonates with unsaturated azlactones was utilized to obtain phosphorylated peptidomimetics with dehydroamino acid moieties. The double bond in the latter was reduced with zinc in acetic acid to provide the corresponding saturated peptidomimetics containing a diethoxyphosphoryl group in the side chain.

Alkoxysilyl derivatives of dibenzoylmethanatoboron difluoride (DBMBF₂) are synthesized by the hydrosilylation reaction of the corresponding O-allyl derivatives of DBMBF₂ with triethoxysilane. The photophysical properties of the synthesized O-allyl and alkoxysilyl derivatives are investigated. It is found that the absorption and fluorescence spectra of the DBMBF₂ derivatives essentially depend on the position of the O-allyl or O-propyl alkoxysilyl substituent. The highest fluorescence quantum yield is obtained for the para-position, whereas the substitution at the meta-position gives the largest bathochromic shift in the fluorescence spectrum. Density functional theory calculations of the structures and time-dependent density functional theory calculations of the gas-phase excitation and emission energies of alkoxysilyl derivatives are performed at the PBE0/SVP level of theory. Some spectral features of para-, ortho-, and meta-substituted derivatives can be adequately explained by the overlapping of two absorption bands.

In the present work, CuCr catalysts supported on γ-Al₂O₃ are prepared and modified with alkali earth elements by impregnation, characterized by N₂ adsorption–desorption, XRD, H₂-TPR (temperature-programmed reduction by H₂), CO₂-TPD and NH₃-TPD (temperature-programmed desorption of NH₃ or CO₂), and applied in the synthesis of 3-methylindole (3-MI) with a N-heterocycle from glycerol and aniline in the fixed-bed reactor. The results show that the introduction of alkali earth elements into the CuCr/Al₂O₃ catalyst can improve the yield of target 3-MI in the order of Mg < Ca < Sr < Ba. CuCr-Ba/Al₂O₃ gives rise to a high 3-MI yield of 39.09% and 65.17% in N₂ as a carrier gas and 20%H₂–N₂ mixture gas, respectively. According to catalysts characterization and catalytic tests, the reaction pathway of glycerol cyclization with aniline is proposed, the formation of 3-MI and 3H-indol-3-yl methanol is hypothesized to be through the aniline cyclization with 2,3-hydroxypropanal from glycerol dehydrogenation over Cu⁰ centers and basic sites. The acidic sites mainly play a role on activating aniline, which interacts with glycerol to form 3-MI or quinoline through cyclization and dehydration.

N,N-Di(arenesulfonyl)-N′,N′-dimethyl-hydrazines, readily prepared from arenesulfonyl chlorides and N,N-dimethylhydrazine, were heated at 120°C in chlorobenzene to give S-aryl arenethiosulfonates, ArSSO₂Ar, in good yields.

A new synthetic approach to aromatic diols substituted with two, three, and four (similar or different) phosphorus groups via the Michael-type addition of the PH bond containing reagents to p-benzoquinone derivatives, reoxidation, and subsequent addition of another phosphorus unit is presented. A variety of new phosphorus-containing p-hydroquinone derivatives were synthesized and fully characterized.

In this work, the geometry optimizations in the ground state and electronic excitation energies and corresponding oscillation strengths of the low-lying electronically excited states for the isolated fluorenone (FN) and FN-based molecular monomers, the relatively hydrogen-bonded dimers, and doubly hydrogen-bonded trimers, are calculated by the density functional theory and time-dependent density functional theory methods, respectively. We find the intermolecular hydrogen bond CO···HO is strengthened in some of the electronically excited states of the hydrogen-bonded dimers and doubly hydrogen-bonded trimers, because the excitation energy in a related excited state decrease and electronic spectral redshift are induced. Similarly, the hydrogen bond CO···HO is weakened in other excited states. On this basis, owing to the important difference of electronegativity, heteroatoms S, Se, and Te that substitute for the O atom in the carbonyl group of the FN molecule have a significant effect on the strength of the hydrogen bond and the spectral shift. It is observed that the hydrogen bond CTe···HO is too weak to be formed. When the CS and CSe substitute for CO, the strength of the hydrogen bonds and electronic spectra frequency shift are significantly changed in the electronic excited state due to the electron transition type transformation from the ππ* feature to σπ* feature. © 2013 Wiley Periodicals, Inc. Heteroatom Chem 24:153–162, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21075

A new reaction of white phosphorus (P₄) with elemental sulfur and thiols in the presence of different amines has been investigated. Ammonium salts of S,S′-dialkyltetrathiophosphoric acids have been observed as main products of the reaction. Octathiotetraphosphetane ammonium salts were formed as side products. The reaction is characterized by a complete conversion of the white phosphorus and is not accompanied by the release of hydrogen sulfide. The crystal structures of both products were determined by the single crystal X-ray diffraction. Biological activity of obtained compounds was investigated, and some promising compounds with antifungal activity identified. © 2013 Wiley Periodicals, Inc. Heteroatom Chem 24:163–167, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21077

Electronic structures of three types of heterostructure armchair BC₂N nanotube besides armchair (4,4)CNT and (4,4)BNNT were calculated by the B3LYP method of density functional theory. The reactivities of nanotubes were discussed by means of obtained vertical ionization potentials and electron affinity potentials. The corresponding electrophilicity values are well correlated with those obtained from the HOMO and LUMO energies of the nanotubes. The good linear correlation found between ω(I,A) and ω(H,L) allows to confirm the use of the easily available B3LYP/6-31G(d) HOMO and LUMO energies to obtain reasonable values of the global electrophilicity index of nanotubes at a lower computational cost. © 2013 Wiley Periodicals, Inc. Heteroatom Chem 24:168–173, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21078

A highly efficient one-pot three-component reaction of aldehydes or ketones, amines, and trimethyl or triethyl phosphite catalyzed by p-dodecylbenzensulfonic acid is developed for the synthesis of α-aminophosphonates at room temperature in water. © 2013 Wiley Periodicals, Inc. Heteroatom Chem 24:174–178, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21079

The earlier described a 3-methyl-1-phenyl-3-phospholene 1-oxide (1) → 6,6-dichloro-1-methyl-3-phenyl-3-phosphabicyclo[3.1.0]hexane 3-oxide (2) → 4-chloro-1-phenyl-1,2-dihydrophosphinine 1-oxide (3) → 4-chloro-5-methyl-1-phenyl-1,2,3,6-tetrahydrophosphinine 1-oxide (4) reaction sequence was investigated from the point of view of preparing optically active intermediates/products (2–4). In principle, both the resolution of the corresponding racemic products and the transformation of the optically active starting materials are suitable approaches for the preparation of optically active six-membered P-heterocycles (2–4). Racemization occurred during the dichlorocyclopropanation reaction of (S)-3-methyl-1-phenyl-3-phospholene 1-oxide ((S)-1), but the thermolytic ring opening of (−)-2, and the selective reduction of α,β-double bond of (−)-3 did not cause the loss of optical activity. First in the literature, the resolution of a 3-phosphabicyclo[3.1.0]hexane 3-oxide (2) and a 1,2,3,6-tetrahydrophosphinine 1-oxide (4) was elaborated. © 2013 Wiley Periodicals, Inc. Heteroatom Chem 24:179–186, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21080

Polyfunctional β-haloalkenyl α-hydroxy phosphonates were synthesized chemoselectively by an economical alkali metal alkoxide catalyzed reaction of dialkyl phosphites with α-haloenals. © 2013 Wiley Periodicals, Inc. Heteroatom Chem 24:187–190, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21081

Two novel series of phosphorus-substituted 3,5-bis(arylidene)piperid-4-ones bearing 1,3,2-oxazaphosphorinane cycle either directly attached to the piperidone core through the PN bond (diamidophosphates 4) or connected with it via thiocarbamoyl linker (thioureas 5) were obtained by the phosphorylation of NH precursors with 2-oxo-1,3,2-oxazaphosphorinane chloride or the reaction of the former ones with the corresponding cyclic isothiocyanate. According to the results of cytotoxicity screening against human carcinoma cell lines (A549, CaOv3, KB), thioureas 5 were more active than the diamidophosphates 4 bearing the same arylidene rings, with compounds with electron-withdrawing side groups displaying IC₅₀ in the micromolar range of 1.2–7 μM. © 2013 Wiley Periodicals, Inc. Heteroatom Chem 24:191–199, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21082

A new series of potentially biological active derivatives, namely alkyl-2-((4-oxo-2-(phenylimino)-3-(β-d-pyranosyl-2-ylamino)thiazolidine-5-ylidene)acetate (5a–f), 4-(4-bromophenyl)thiazol-2(3H)-ylidene)hydrazinyl)-β-d-pyranosyl (4a–c), and 5-(4-bromophenyl)-2-(phenylimino)-3-(β-d-pyranosyl-2-ylamino)thiazolidine-4-one (6) were synthesized via a reaction of the sugar thiosemicarbazone derivatives with 2,4′-dibromoacetophenone, dialkylacetylenedicarboxylate, and ethylbromoacetate, respectively. The structures of the synthesized compounds were established by spectroscopic methods (FT-IR, ¹H NMR, ¹³C NMR, and 2D NMR) and elemental analyses. Furthermore, the effect of various solvents at reflux and also ambient temperature on the reactions of the sugar thiosemicarbazone with 2,4′dibromoacetophenone, diethyl acetylenedicarboxylate, and dimethyl acetylenedicarboxylate was investigated. © 2013 Wiley Periodicals, Inc. Heteroatom Chem 24:200–207, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21083

4-Phenyl-2-aminothaizole was diazotized and coupled with N-(alkyl)-2-oxo-3-cyano-4-methyl-6-hydroxypyridine (2-pyridone). The resultant dyes were named as N-(alkyl)-6-hydroxy-4-methyl-2-oxo-5-((4-phenylthiazole-2-yl)diazenyl)-1,2-dihydro pyridine-3-carbonitrite and duly characterized. The diazotized aryl amines were then coupled to a moiety of above-mentioned dyes at 5-position of thiazole. The obtained bisheteroaryl azo dyes were characterized by elemental analysis and spectral studies. Solvent effects on the visible absorption spectra of the dyes were evaluated. The color of the dyes is discussed with respect to the nature of the heterocyclic ring, aromatic amines, and substituents present therein. All these dyes were applied as disperse dyes on to polyester fabrics, and their fastness properties were evaluated. © 2013 Wiley Periodicals, Inc. Heteroatom Chem 24:208–220, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21085

The microwave-assisted Kabachnik–Fields reaction of a series of 3-amino-6-methyl-2H-pyran-2-ones, paraformaldehyde, and dialkyl phosphites or diphenylphosphine oxide led to α-aminophosphonates or α-aminophosphine oxides, respectively. The α-aminophosphonates were obtained under solvent-free conditions, whereas the α-aminophosphine oxides in acetonitrile. The novel products were characterized by NMR and mass spectral data. © 2013 Wiley Periodicals, Inc. Heteroatom Chem 24:221–225, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21086

New dihydro[3,2-c][1,2,4]triazolo[4,3-a]pyridines were synthesized by the reaction of 4-(methylsulfanyl)-6,7-dihydrothieno[3,2-c]pyridine with acid hydrazides. One bis(dihydrothienotriazolo-pyridine) was also prepared. In a few cases, the corresponding intermediate could be detected by LC-MS. The bromophenyl derivative was involved in Suzuki and Sonogashira cross-coupling reactions. © 2013 Wiley Periodicals, Inc. Heteroatom Chem 24:226–233, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21087

The synthesis of tetraethyl 1,2-epoxy-2-aryl ethylgembisphosphonates by direct epoxidation of 2-aryl,vinyl-1,1-diphosphonate derivatives with ethyl methyldioxirane generated in situ from potassium hydrogen monopersulfate (caroate) and butanone in a phase transfer system is reported. The epoxides were isolated in excellent yields and fully characterized by spectral and microanalytical data. © 2013 Wiley Periodicals, Inc. Heteroatom Chem 24:234–241, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21084