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The palladium-catalyzed cross-coupling reaction of aryl iodides with 3,3,3-triethoxy-1-propyne gave 1-aryl-3,3,3-triethoxy-1-propynes which were converted to the corresponding ethyl arylpropiolates. The arylpropiolates were also synthesized from the cross-coupling reactions of aryl iodides with 2-ethoxycarbonyl-1-ethynylzinc chloride or ethyl (tributylstannyl)propiolate, but the reactions were not generally applicable

1,3-Dipolar cycloaddition reaction of diazomethane and ethyl diazoacetate with tributylstannyl-acetylenes occurred regioselectively to afford the corresponding 3(5)-tributylstannylpyrazoles. The cycloaddition reaction of 3-phenylsydnone with the stannylacetylenes proceeded also regioselectively, and 3-tributylstannyl-1-phenylpyrazoles were isolated. 4-Tributylstannyl- and 5-tributylstannyl-1-phenylpyrazole were prepared by the stannylation of 4-lithio- and 5-lithio-1-phenylpyrazoles with tributylstannyl chloride. Iodination, benzoylation, and phenylation of the stannylpyrazoles were examined

The reaction of 3-bromopyridine with phenylacetonitrile in the presence of NaH in THF gave a simple substitution product, α-phenyl-3-pyridineacetonitrile, whereas the reaction of 5-bromopyrimidine with phenylacetonitrile under similar conditions gave a ring-transformation product, 2-amino-5-bromo-3-phenylpyridine. 3-bromoquinoline and 4-bromoisoquinoline underwent the former type reaction, while 3-bromo- and 3-chloroisoquinolines were converted into 2-amino-3-phenyl-1-naphthalencarbonitrile according to the latter type reaction

Inverse electron-demand Diels-Alder reaction of 3,6-disubstituted 1,2,4,5-tetrazines with tributylstannylacetylenes containing a substituent gave 4-(tributylstannyl)pyridazines. Particularly, dimethyl 1,2,4,5-tetrazine-3,6-dicarboxylate gave 4-(tributylstannyl)pyridazines in good yields. Substitution reaction of 3,6-diphenyl-4-(tributylstannyl)pyridazine was also described

The oxidative addition of active zinc to bromo- and iodopyridines gave pyridinylzinc halides which were coupled with aryl halide or benzoyl chloride in the presence of a palladium catalyst.

Condensation of halo-substituted 1,3-azoles (1,3-oxazoles, 1,3-thiazoles and imidazoles) with phenylsulfonylacetonitrile under basic conditions was promoted by catalytic action of tetrakis(triphenylphosphine)palladium(0) to give α-phenylsulfonyl-1,3-azoleacetonitriles. The adaptability of halogen atoms for the cross-coupling reaction was investigated. The reaction of 4-halo-1,2-azoles was also examined

4 H -1,3-Dioxin was firstly arylated by using Heck reaction, and the reaction in the presence of ( R )-BINAP gave enantiomerically enriched 4-phenyldioxin which was converted into optically active 1-phenyl-1,3-propanediol.

Rigidin, a marine alkaloid, was synthesized by the combination of acylation via lithiation and arylation by palladium-catalyzed reaction starting from 2,4-dimethoxypyrrolo[2,3- d ]pyrimidine.

Methyl 2-(nitrogen-heteroaryl)propanoates were synthesized by the palladium-catalyzed reaction of heteroaryl halides with (E)-1-methoxy-1-trimethylsiloxypropene

The oxidative addition of active zinc to iodo- and bromo-substituted π-deficient heteroarenes such as pyridine, pyrimidine, and quinoline gave the corresponding heteroarylzinc halides which were transformed to the arylated and benzoylated derivatives by palladium-catalyzed reaction.

1,3-Dioxep-5-ene was arylated by using Heck reaction, and the arylated 1,3-dioxep-4-ene derivatives were easily converted into 4-arylbutyrolactones, intermediates for the synthesis of natural products and biological active compounds

Indolylzinc derivatives were prepared by the oxidative addition of active zinc to iodoindoles, which coupled with aromatic halides in the presence of palladium catalyst to give arylated indoles.

3-Methyleneindoline derivatives were synthesized by intramolecular Heck reaction of N-allyl-2-iodoaniline derivatives in the presence of Ag2Co3. This method was successfully applied to the synthesis of the CC-1065/duocarmycin pharmacophore.

1, 3-Dipolar cycloaddition reaction of trimethylstannylacetylene with nitrile oxides yielded 3-substituted 5-(trimethylstannyl)isoxazoles. On the other hand, the same reaction of (trimethylstannyl)phenylacetylene, -1-hexyne, and -(trimethylsilyl)acetylene gave 3, 5-disubstituted 4-(trimethylstannyl)isoxazoles almost regioselectively. The regioselectivity of the cycloaddition reaction is interpreted by application of the frontier-electron theory.

Palladium-catalyzed reaction of aryl and heteroaryl iodides with ethoxy(trialkylstannyl)acetylenes gave the ethoxyethynylarenes and -heteroarenes, which were easily transformed by hydration reaction into ethyl areneacetates and heteroareneacetates.

The marine alkaloid rigidin has been synthesized from 2,4-dimethoxy-7-phenylsulfonylpyrrolo[2,3-d]pyrimidine. Lithiation of the pyrrolo[2,3-d]pyrimidine followed by electrophilic substitution with N, 4-dimethoxy-N-methylbenzamide afforded a 6-(4-methoxy)benzoyl derivative which by alkaline hydrolysis and subsequent iodination was converted into 2,4-dimethoxy-5-iodopyrrolo [2,3-d] pyrimidin-6-yl 4-methoxyphenyl ketone. The palladium-catalysed arylation of this with 2-(4-methoxyphenyl)-1,3,2-dioxaborinane followed by demethylation with boron tribromide gave rigidin.

The Cu(I)-catalyzed boration of an α,β-enone using a diboron is described. Combination of a Cu(I) salt and tributylphosphine is an effective catalyst system, though the individual use of Cu(I) and tributylphosphine is not active for the reaction.

Nucleophilic addition-elimination reactions of 2-methylsulfonyl-1,3-azoles with active methylene compounds were investigated in order to compare the reactivity of substrates. The order of oxasole > thiazole >> N-methylimidazole in the reactivity was exhibited clearly. Furthermore, in oxazole and thiazole series, the predominant reactivity of the 2-position over the 4- and 5-positions was indicated on the reaction with the carbanions generated from active methylene compounds

The syntheses and reactions of pyrimidines N-oxides are reviewed. Pyrimidines having alkyl, aryl, and alkoxyl groups are convertible to their mono-N-oxides by N-oxidation with an organic peroxy acid. The position of the N-oxide group can be elucidated by physical methods. Pyrimidine N-oxides are highly reactive to various nucleophilic reagents owing to their π-deficient character. The reactivity of a methyl group enhanced by introducing an N-oxide group and the characteristic ring-cleavage of N-oxides are also described

A number of 2-substituted 4,5-diphenylthiazoles were synthesized by the nucleophilic substitution of 2-methylsulfonyl-4,5-diphenylthiazole with various sodium alkoxides, amines, and carbanions of active methylene compounds. 2-Methylsulfonyl-4,5-diphenylthiazole was obtained by the potassium permanganate oxidation of 2-methylthio-4,5-diphenylthiazole in the presence of a phase-transfer catalyst. 2-Ethoxy-4,5-bis(4-methoxyphenyl) thiazole was prepared in a similar manner. 2-Ethynyl-4,5-diphenylthiazoles were synthesized by the palladium catalyst cross-coupling reaction of 2-iodo-4,5-diphenylthiazole with monosubstituted acetylenes. These compounds were tested for inhibitory activity against blood platelet aggregation in vitro. Among them, 2-alkoxy-, and 2-(4-methylpiperazin-1-yl)-4,5-diphenylthiazole were found to have potent inhibitory activity.

Title reaction is well prompted by the catalytic action of dichlorobis(triphenylphosphine)palladium in dimethylformamide in the presence of tetraethylammonium chloride to give (Z)-1-ethoxy-2-(4-substituted phenyl)ethene. The method is also useful for the introduction of a 2-ethoxyethenyl moiety into heteroaromatic rings such as pyridine, thiophene, indole

3-Substituted 5-(tributylstannyl)isoxazoles were synthesized in good yields by the 1,3-dipolar cycloaddition reaction of ethynyltributylstannane with nitrile oxides generated in situ . 3-Methyl-5-(tributylstannyl)isoxazole was easily converted to the corresponding 5-benzoyl- and 5-arylisoxazoles by the palladium-catalyzed reaction.

4-Chlorothieno[2,3-d]pyrimidines were prepared by the chlorination of 4-oxo-3,4-dihydrothieno[2,3-d]pyrimidines with phosphoryl chloride. 4-Oxo-3,4,5,6,7,8-hexahydro[1]-benzo- and 4-oxo-6-phenylthieno[2,3-d]pyrimidine were synthesized by the cyclization of 2-acylaminothiophene-3-carboxamide derivatives with base. 2-Methyl-4-oxo-3,4-dihydrothieno[2,3-d]pyrimidine was prepared by the treatment of 2-methyl-4-trichloromethylthieno-[2,3-d]pyrimidine with sodium hydroxide in aqueous methanol. A series of 4-alkylamino- and 4-arylaminothieno[2,3-d]pyrimidines were synthesized by the nucleophilic substitution of 4-chlorothieno[2,3-d]pyrimidines with various amines. These compounds were evaluated for antifungal activity against Piricularia oryzae. The preventive effects on Rice blast, Sheath blight, and Cucumber powdery mildew were also determined by pot tests.

The reflectance and structure changes of iridium oxide films by reduction were investigated in an attempt to apply the films to optical data storage media. The films were prepared by the thermal oxidation of iridium-carbon composite films. The films were easily reduced by heating them in 5% H/sub 2/ in Ar at temperatures in the range 100/sup 0/-300/sup 0/C. When the films were reduced, the particles size of Ir metal and the reflectance of the films increased with an increase in the reducing temperature. The reduced films were stable against oxidation at temperatures of 250/sup 0/C or higher. Optical writing on the films was carried out with an argon laser at 0.84W power. The writing mechanism was based on changes in the film's optical properties caused by laser-induced reduction.