Selective phosphorylation of dihydroquercetin with trivalent phosphorus reagents

Characteristic features of phosphorylation of dihydroquercetin with trivalent phosphorus reagents were studied. Preparative methods for regioselective phosphorylation were found. The most important chemical properties of dihydroquercetin phosphites and cyclophosphites were studied. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:399–403, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10115     

3‐Aryl‐5‐furylpyrazolines and their biological activities

Aryl‐furyl substituted pyrazolines 2a–c and 4a–c were prepared by the reaction of α,β‐unsaturated carbonyl compounds with hydrazine or phenyl hydrazine. N‐chloroacetyl derivatives 3a–c were obtained by the N‐acetylation of 2a–c . The antibacterial activities of synthesized pyrazolines were examined by employing the disk‐diffusion technique. All synthesized compounds showed antibacterial effects in 1200 μg concentration. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:345–347, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10159     

Studies on reactivity of ketosulfones

The cycloaddition of diazomethane, cyclocondensation of hydrazine hydrate, and cyclopropanation of TMSOI to 1‐aroyl‐2‐styrylsulfonylethenes were studied and different novel products thereby obtained were characterized with spectral parameters. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:155–159, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10117     

Conversion of 2(3H)‐furanones bearing indole nuclei into novel amide,pyrrolone, and imidazole derivatives

2(3H)‐Furanones 1a–d having exocyclic double bond and N‐acetylisatin nucleus were converted into the corresponding novel amides, pyrrolones, and imidazoles via nitrogen nucleophiles. All purposed structures were confirmed by NMR, mass spectra GC/MS, and chemical evidence. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:434–442, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10175     

Photodesulfurization of 2,4‐diaryl‐1,2, 4‐triazole‐3‐thiones

Irradiation of triazole thiones in thin‐film reactor furnished the corresponding desulfurized triazoles in good yield. The required triazole thiones were synthesized from the respective acid hydrazide and isothiocyanate. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:269–272, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10140     

A convenient synthesis of diacyl sulfides using a novel sulfur transfer reagent

Various diacyl sulfides were synthesized by reaction of acyl chlorides with LiAlHSH. Reaction of glutaryl chloride with LiAlHSH afforded glutaric thioanhydride. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:633–635, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10217     

Synthesis of N‐aryl S‐alkylthiocarbamates

Several N‐aryl S‐alkylthiocarbamates were synthesized by reactions of isocyanates with LiAlHSH and then with alkyl halides. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:374–378, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10163     

A facile approach to phosphonic acid diesters

The symmetric H‐phosphonates of carbohydrate and other compounds were conveniently prepared by direct transesterification of the corresponding monohydroxylic compounds with diphenyl phosphite. The approach has the merits of mild reaction conditions and high yields. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:208–210, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10130     

Conversion of 2(3H)‐furanones into 1,3,4‐oxadiazoles

A series of 2‐phenyl‐5‐alkenyl‐1,3,4‐oxadiazoles were synthesized in high yields from the corresponding dicarbonylhydrazides through cyclodehydration. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:570–574, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10197     

Synthesis of novel thia‐oxadiazolophanes

The novel thia‐1,3,4‐oxadiazolophanes were synthesized regioselectively from 1,4‐bis(5‐mercapto‐1,3,4‐oxadiazol‐2‐yl)butane and various 1,ω‐dihaloalkanes in presence of potassium hydroxide. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:273–275, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10141     

Cycloaddition of nitrile oxides to substituted vinylphosphonates

Cycloaddition of nitrile oxides to substituted vinylphosphonates was performed. A series of 4,5‐dihydroisoxazoles containing phosphonyl group were synthesized under very mild condition in excellent regiospecificity. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:309–311, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10149     

A convenient synthesis of substituted 3‐alkoxycarbonyl‐β,γ‐unsaturated esters with predominant Z‐selectivity

The consecutive reaction of bis[2,2,2‐trifluoroethyl]phosphite with sodium hydride, dimethyl maleate, and aldehydes gives 3‐alkoxycarbonyl‐β,γ‐unsaturated esters with predominant Z‐selectivity in 62–94% yields (Z/E = 85–60:15–40). The Z‐ and E‐isomer can be separated conveniently by column chromatography. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:276–279, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10142     

Synthesis of α‐aminophosphinates by the hydrophosphinylation of imines

Numerous substituted α‐aminophosphinates were synthesized by addition of alkyl and phenyl H‐phosphinates to aromatic imines and characterized. Modest diastereoselectivity was observed in the reaction. The size of the substituents exerts a small effect on the diastereoselectivity of P C bond formation. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:235–240, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10133     

Syntheses of 3,4,7‐triazaacenaphthylene and pyrido[3,4,5‐de]cinnoline derivatives

The title compounds were prepared by four different routes: (1) reaction of cycloalkanopyridazines 3a–e with trichloroacetonitrile in basic medium; (2) reaction of 3a–d with DMF DMA, followed by nucleophilic treatment with a primary amine; (3) reaction of 2‐(dimethylamino)methylene‐cycloalkylidene‐malononitrile with arene diazonium salt, followed by amine treatment; (4) reaction of cycloalkylidenemalononitrile with phenyl or benzoyl isothiocyanate and heating the product with diazoaminobenzene. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:427–433, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10168     

Syntheses of cyanoselenoamides and diselenoamides: Conversion into selenazoles and selenazines

Reactions of dicyano compounds with a potassium selenocarboxylate afforded the corresponding cyanoselenoamides and diselenoamides in good yields of experimentally determined ratios. The obtained cyanoselenoamides were allowed to react with potassium selenocarboxylate, again to afford the corresponding diselenoamides in higher yields. The cyanoselenoamides and diselenoamides were investigated as substrates for preparations of selenazoles and selenazines. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:106–110, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10111     

Cycloaddition of bis‐1,3‐dipolar reagents to 1,3‐diarylprop‐2‐en‐1‐ones

Bis pyrazolines and isoxazolines were prepared by 1,3‐dipolar cycloaddition of benzene‐1,3/1,4‐dicarboxaldehyde dihydrazones and dioximes to 1,3‐diaryl‐prop‐2‐en‐1‐ones. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:379–383, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10169     

Reactivity of pyridazin‐3(2H) thiones

4,6‐Disubstituted pyridazin‐3(2H) thiones 3a–f were prepared by thiation of 4,6‐disubstituted pyridazin‐3(2H)‐one 1a–f either with thiourea or phosphorus pentasulphide. The reactivity of 3a‐f towards nucleophilic and electrophilic species under different conditions was studied successively. The structure of the products was confirmed by NMR and mass spectral data. Mechanisms for their formation are also proposed. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:334–341, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10157     

Novel cyclization of dimeric dianions of anils or aldehydes with triphosgene: A safe and efficient synthesis of substituted imidazolidin‐2‐ones and 4,5‐diaryl‐1,3‐dioxolan‐2‐ones

The reaction of Schiff bases or aldehydes with samarium diiodide in dry THF, followed by addition of triphosgene, gives substituted imidazolidin‐2‐ones and 4,5‐diaryl–1,3‐dioxolan‐2‐ones, respectively, in moderate to good yields under mild conditions. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:46–49, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10065     

Report on the 28th symposium on heteroatom chemistry of the chemical society of Japan

The 28th domestic Symposium on Heteroatom Chemistry of the Chemical Society of Japan was held at Saitama Culture Center in Saitama during the period of December 12–14, and about 250 chemists from various academic institutes and industries took part in the symposium. There were four plenary lectures, 44 oral presentations, and 52 poster presentations. The present article describes abstracts of the plenary lectures and graphical abstracts of oral presentations. Titles of poster presentations are also given. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:1–12, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10073     

Oxidative cyclization in the synthesis of 5‐ and 6‐membered N,O‐heterocycles

The versatility and potential of oxidative cyclization in the synthesis of 5‐ and 6‐membered N‐ and/or O‐heterocycles is presented through judiciously selected examples.© 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:642–670, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10200