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A rhenium complex, (ReBr(CO) 3 (thf)) 2 , catalyzed insertion of terminal alkynes into a C-H bond of active methylene sites of 1,3-dicarbonyl compounds. When a catalytic amount of isocyanide or molecular sieves was added to the reaction mixture, the reaction course changed markedly, and insertion of alkynes into a C-C single bond between α- and β-positions of cyclic and acyclic β-keto esters occurred. The formed acyclic δ-keto esters could be converted to 2-pyranones, which were applied to the synthesis of multisubstituted aromatic compounds via the Diels-Alder reaction and successive elimination of carbon dioxide. In the case of the rhenium-catalyzed reactions between terminal alkynes and β-keto esters without substituent at the α-position, tetrasubstituted benzenes were produced regioselectively by two-to-one reaction of the components. The yields of tetrasubstituted benzenes were improved by using a manganese catalyst.

The arylation of benzanilide (I) possessing ether oxygen(s) proceeds under phosphine-ligand free conditions to afford the para-product (II) and the ortho-product (III) in a similar ratio as in the presence of the P(o-Tol)3 ligand, suggesting that the bulkiness of palladium under phosphine-free conditions is comparable to that under P(o-Tol)3 conditions.

Biruthenocene was prepared in high yield by a radical reaction of ruthenocene in sulfuric acid at 80°C. Biruthenocene reacts with FeIII salts, HX (X; Br, Cl), and NH4PF6, giving diamagnetic biruthenoceniumX+PF−6 salts. Based on the 13C-Cp-MAS, 13C-, and 1H-NMR spectroscopic studies of the salts, it was found that the structure is expressed as [RuIICp(C5H4)(C5H4)(C5H4)CpRuIVX]+PF−6 in solid, and there is a rapid intramolecular electron transmission between the two Ru atoms, [RuIICp*(C5H4)(C5H4)CpRuIVX]+ ⇌ [XRuIVCp*(C5H4)(C5H4)CpRuII]+, in acetonitrile.

Reaction of allyltris(trimethylsilyl)silane with organic halides under the free radical conditions resulted in allylation of the halides in modrate to good yields. The presence of three trimethylsilyl groups on the silicon could enhance the homolytic dissociation of a Si–C bond in the β-silylalkyl radical.

The Catalytic properties of ISI-1, 3, 4, 5 and 6, synthesized in mixtures of water and organic solvent, have been studied. Although having acidic properties similar to a sample of ZSM-5 zeolite comprising small and aggregated crystallites, the five zeolites showed low selectivities for C 5 + product and fraction of aromatics in the C 5 + product in syngas-to-gasoline and methanol-to-gasoline reactions. Under methanol-to-gasoline reaction conditions, ISI-3, 4, 5 and 6 showed a high production of p -xylene in the xylene product. From the results of physicochemical measurements, the unique Catalytic properties of each ISI zeolite can be attributed to its crystal structure, pore size and large crystallite size.

Poly-γ-benzyl-L-glutamate (PBLG) when treated with a silane coupling agent on a glass surface forms a molecular oriented film; a new liquid crystal texture induced by the α-helical structure of PBLG attached to the substrate surface is observed.

The photoreaction of 10-methylacridone with N,N-dimethylaniline proceeds via the triplet state of the former and results in electron transfer followed

1,8-Di(2-thienyl)-, 1,8-bis(5,2′-bithiophene-2-yl)-, 1,8-bis(5,2′:5′,2″-terthiophene-2-yl)-, and 1,8-bis-(5,2′:5′,2″:5″,2″′-quaterthiophene-2-yl)naphthalenes (1a, 1b, 1c and 1d, respectively) were synthesized starting from 1,8-dibromonaphthalene by appliction of NiCl2(dppp)-catalyzed coupling of aryl bromides with thienylmagnesium bromides. For comparison with these compounds, 1-(2-thienyl)-, 1-(5,2′-bithiophene-2-yl)-, 1-(5,2′:5′,2″-terthiophene-2-yl)-, and 1-(5,2′:5′,2″:5″,2″′-quaterthiophene-2-yl)naphthalenes (2a–d) were also prepared. Inspection of 1H and 13C NMR and UV/Vis data of 1a–d and 2a–d including X-ray single crystal structure data of 1b suggests that the planes of two oligothiophene units of 1a–d are approximately parallel to each other and are at large angles to the naphthalene ring. In accordance with these findings, CV oxidation potential data show that the radical cations formed from 1a–d are stabilized by intramolecular electron transfer interaction of the two oligothiophene units.

Esterification reactions from cyclic 1,3-diketones and alcohols are carried out in the presence of several Lewis acids. In particular, indium(III) triflate, In(OTf)(3), iron(III) triflate, Fe(OTf)(3), copper(II) triflate, Cu(OTf)(2), and silver(I) triflate, AgOTf, show high catalytic activities. These reactions proceed through the carbon-carbon bond cleavage by a retro-aldol reaction and were found to be highly regioselective even in the presence of other functional groups. This type of reaction can also be applied to the preparation of the keto esters during the synthesis of seratrodast, which is an antiasthmatic and eicosanoid antagonist.

Three new β-coumaranones, sparanone A, sparanone B and sparanoside B, were isolated from bulbs of Sparaxis tricolor. Their stereostructures were established on the basis of chemical evidence and spectroscopic studies.

Treatment of 2,2-dimethyl-6-nonene-4,8-diynal (2) with CeCl3/LiN(TMS)2 at −5∼25°C gave 2,2-dimethyl-1-indanol (3) in a moderate yield. In the present study, acyclic (Z)-enediyne aldehyde (2) was cyclized to afford a nine-membered monocyclic enediyne (7), which cycloaromatized spontaneously at room temperature.

Coupling of the azatyrosine fragment with the cyclopentadiene monoepoxide derivative corresponding to the core moiety of the kedarcidin chromophore has been effectively achieved using CsF.

Irradiation of chromone-2-carboxylic acid in aerated ethanol solution gives 4-hydroxycoumarine with the quantum yield of 0.02. The reaction proceeds via the decarboxylation followed by the addition of the oxygen molecule. Chemiluminescence measuring was successfully applied to detect the ketohydroperoxide intermediate in the photoreaction.

Dimeric fluorescent compounds were formed from an (E)-5,5′-diphenyl-2,2′,3,3′-tetrahydro-3,3′-bipyrrolylidene-2,2′-dione by a treatment with acid anhydride and TFA. The structures of these compounds were clarified by X-ray analysis and spectral (UV-vis, 1H and 13C NMR) comparisons.

Irradiation (λ >300 nm) of coumarin-3-carboxylic acid gives the decarboxylated 4,4′-dimer of chroman-2-one, the structure of which is quite different from that of [π2s+π2s] cycloaddition dimer as is observed in the past in the photoreaction of coumarin or some of its derivatives.

We have succeeded in the development of three approaches to the synthesis of aromatic compounds from 1,3-dicarbonyl compounds and alkynes. The first approach is a manganese-catalyzed [2+2+2] cycloaddition between 1,3-dicarbonyl compounds, which have no substituents at the active methylene moiety, and terminal alkynes. This reaction proceeds with high regioselectivity when aryl acetylenes are employed as the alkyne component. The second approach is a rhenium- or manganese-catalyzed formal [2+1+2+1] cycloaddition between beta-keto esters and two kinds of alkynes. In this reaction, the aromatic compounds are obtained by the following reaction sequence: (1) insertion of the first alkyne into a carbon-carbon single bond of a beta-keto ester, (2) formation of 2-pyranones via intramolecular cyclization with the elimination of ethanol, and (3) Diels-Alder reaction between the formed 2-pyranone and the second alkyne. This reaction provides multisubstituted aromatic compounds in a regioselective manner. The third approach is a rhenium-catalyzed formal [2+2+1+1] cycloaddition reaction from two 1,3-diketones and one alkyne. In this reaction, the aromatic skeleton is constructed from three carbons of the first 1,3-diketone, two carbons of the alkyne, and one carbon of the second 1,3-diketone.

Treatment of alkynes with cyclic and acyclic 1,3-dicarbonyl compounds in the presence of a catalytic amount of a rhenium or manganese complex gives ring-expanded and carbon-chain extension products, respectively. In these reactions, alkynes insert into a non-strained carbon-carbon single bond of 1,3-dicarbonyl compounds. The ring-expansion reaction is also promoted by the addition of 4-A molecular sieves instead of a catalytic amount of an isocyanide.

A combination of catalytic amounts of [ReBr(CO)3(thf)]2 and tetrabutylammonium fluoride (TBAF) promoted the dimerization of aryl- and alkenyl-substituted alkynes with high regio- and stereoselectiv...

Treatment of cyclic β-keto esters with terminal alkynes in the presence of a catalytic amount of a rhenium complex, [ReBr(CO)3(thf)]2, gave bicyclo[3.3.1]nonene derivatives. The reaction conditions and yields of the bicyclo[3.3.1]nonenes were improved by the sequential use of tetrabutylammonium fluoride (TBAF) after the rhenium-catalyzed reactions.

Rhenium- and manganese-catalyzed reactions between β-keto esters and acetylenes, followed by treatment with tetrabutylammonium fluoride, gave 2-pyranone derivatives regioselectively.

A reaction between a β-keto ester and an acetylene in the presence of a rhenium complex, [ReBr(CO)3(thf)]2, as a catalyst, provided a 2-pyranone derivative in excellent yield via retro-aldol reaction (C−C single bond cleavage). By adding an acetylene-bearing ester group(s) after the formation of 2-pyranones, an aromatization reaction proceeded and multisubstituted aromatic compounds were obtained in good to excellent yields.

Rhenium complex, (ReBr(CO) 3 (thf)) 2 -catalyzed reactions between aromatic imines and either acetylenes or α,β-unsaturated carbonyl compounds gave indene derivatives in good to excellent yields. These reactions proceed via C-H bond activation, insertion of acetylenes or α,β-unsaturated carbonyl compounds, intramolecular nucleophilic cyclization, and reductive elimination. Indene derivatives were also obtained from aromatic ketones and α,β-unsaturated carbonyl compounds in the presence of catalytic amounts of the rhenium complex and p-anisidine. Sequential ruthenium-catalyzed hydroamination of aromatic acetylenes with anilines, and rhenium-catalyzed reactions of the formed aromatic ketimines with α,β-unsaturated carbonyl compounds also provided indene derivatives.

Isomerization between two isomers of 1,2-disubstituted 3-aminoindenes occurs via the rearrangement of indene frameworks. In contrast to previous rearrangements of indene derivatives, which occur under high-temperature conditions or the irradiation of light, this rearrangement proceeds at room temperature without UV light irradiation. An amino group at the 3-position plays an important role to accelerate the rearrangement under mild conditions.

This chapter attempts to give an overview of the historical development and current progress of femtosecond laser micro-nanofabrication based on multiphoton absorption, and particular emphasis is placed on two-photon photopolymerization. Femtosecond laser interaction with matter differs essentially from those with longer pulses or CW lasers in its significant nonlinearity, ultrafast characteristics and the possibility of highly localization of reaction volume. These features enable three-dimensional (3D) micro-nanofabrication in solid and liquid media. In two-photon photopolymerization, when a near-infrared femtosecond laser is tightly focused into a photopolymerizable resin, 3D polymer micro-nanostructures are produced by pinpoint photopolymerization of liquid precursory resins. Using this direct laser writing scheme, various photonic, micro-optical components and micromechanical devices have been readily produced. The two-photon photopolymerization technology is expected to play a similar role to that played by lithography for planar semiconductor device processing, but for micro-nanofabrication of 3D polymer-based optoelectronic devices as well for microelectromechanical systems.

Our continuing program to develop new antifolate drugs useful against rheumatoid arthritis led us to modify the pteridine ring of gamma-fluoromethotrexate. Pyrrolopyrimidine derivatives 1e and 1t were found to exhibit potent suppressive effects on the responses of both T and B cells to mitogens, although tetrahydropyridopyrimidine derivatives 2e and 2t and quinazoline derivatives 3e, 3t and 4e showed very weak suppressive activities. Thus, conversion of the pteridine ring of gamma-fluoromethotrexate to a pyrrolopyrimidine ring led to a new potential antirheumatic compound.