Language：Others  

Gold-Catalyzed Facile Synthesis and Crystal Structures of Benzene-/Naphthalene-Based Bispentalenes as Organic Semiconductors

DOI： 10.1002/chem.201805637

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/ejoc.202200873

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1055/a-1739-4793

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1039/d1cc06212c

Language：English   Publishing type：Research paper (scientific journal)  

Tribenzosilepins were synthesized from terphenyls and dihydrosilanes via a facile approach using a double sila-Friedel-Crafts reaction. Several silepin derivatives were obtained in moderate to high yield. The reaction system was found to be suitable for synthesizing a bidirectional silepin. Furthermore, the transformation of the amino groups of tribenzosilepin derivatives to aryl groups and the extension of the backbone π-system in tribenzosilepin were demonstrated.

DOI： 10.1039/d1cc02326h

Language：English   Publishing type：Research paper (scientific journal)  

Often stoichiometric amounts of gold find use in materials science; occasionally gold is even used as a support. This review discusses the contributions of gold catalysis, both homogeneous and heterogeneous, to the field of materials science. One topic is the synthesis of polymers, including nanowires and polyesters, the postcyclization of polymers, polymerization by cyclopropanation, and gold-catalyzed radical polymerization reactions. Other topics are dyes, phosphonium salts, and a wide range of extended conjugated π-systems, the latter ranging from acenes, pentalene derivatives, and different heterocyclic π-systems to fascinating applications in the synthesis of helical anellated aromatic molecules. The existing contributions clearly demonstrate the potential of gold catalysis for significant future impulses for the field of materials science.

DOI： 10.1021/acs.chemrev.0c00824

Language：English   Publishing type：Research paper (scientific journal)  

A simple gold-catalyzed annulation of 1,8-dialkynylnaphthalenes utilizing a cationic gold catalyst was developed. Such a peri-position of two alkynyl substituents has not been studied in gold catalysis before. Dependent on the substrate, the reactions either follow a mechanism involving vinyl cation intermediates or involve a dual gold catalysis mechanism which in an initial 6-endo-dig-cyclization generates gold(I) vinylidene intermediates that are able to insert into C-H bonds. Indenophenalene derivatives were obtained in moderate to high yields. In addition, the bidirectional gold-catalyzed annulation of tetraynes provided even larger conjugated π-systems. The optoelectronic properties of the products were also investigated.

DOI： 10.1002/chem.202004846

Language：Others   Publishing type：Research paper (scientific journal)  

<p>Additives enhance the performance of a recyclable ruthenium-triphos catalyst system in the hydrogenation of carbon dioxide to dimethoxymethane.</p>

DOI： 10.1039/d0gc02528c

Language：English   Publishing type：Research paper (scientific journal)  

We synthesised novel hexacoordinated organosilicon compounds with two 2-(2-pyridyl)phenyl groups. Single-crystal X-ray structure analyses indicated that Lewis acid-base interactions exist between the silicon atom and two nitrogen atoms of the pyridine rings, and that hexacoordinated organosilicon compounds have slightly distorted octahedral structures in the solid state. The hexacoordinated organosilicon compounds are stable in air, water, heat, acids, and bases. The fluorescent quantum yield increased dramatically and a significant red-shift of the maximum fluorescence wavelength was observed with the introduction of amino groups on the 2-(2-pyridyl)phenyl aromatic rings. The fluorescence colours of a hexacoordinated organosilicon compound with two amino groups can be switched by protonation and deprotonation (neutralisation) of the amino groups.

DOI： 10.1039/d0ob00484g

Language：English   Publishing type：Research paper (scientific journal)  

We have developed a catalytic synthetic method to prepare phenoxasilins. A borane-catalyzed double sila-Friedel-Crafts reaction between amino group-containing diaryl ethers and dihydrosilanes can be used to prepare a variety of phenoxasilin derivatives in good to excellent yields. The optimized reaction conditions were also applicable for diaryl thioethers to afford their corresponding six-membered silacyclic products. The gram-scale synthesis of a representative bis(dimethylamino)phenoxasilin and the transformation of its amino groups have also been demonstrated.

DOI： 10.3762/bjoc.16.39

Language：Others   Publishing type：Research paper (scientific journal)  

© 2019 The Royal Society of Chemistry. The solubilizing side-groups of solution-processable π-conjugated organic semiconductors affect both the crystal structure and microstructure of the respective thin films and thus charge-carrier mobility in devices. In this work, we explore how the alkyl side-chain length influences thin-film structure and charge transport in field-effect transistors of zone-cast, naphthalene-based bispentalenes. By tuning the alkyl-chain length and the casting speed, we alter the microstructure from highly aligned ribbons, to feathered ribbons, to disordered grains. Concurrently, the hole mobility changes over two orders of magnitude, from 0.001 cm2 V-1 s-1 at the fastest speeds to roughly 0.1 cm2 V-1 s-1 at slower speeds. The highest mobilities correspond to the presence of an aligned ribbon morphology. While optical measurements indicate negligible electronic differences between the molecules, grazing incidence X-ray diffraction measurements show that the films display different degrees of order and alignment. The compound with pentyl side-chains exhibits the largest tolerance to different processing conditions, yielding an aligned ribbon microstructure and high mobility over a wide range of casting speeds. Our results highlight the impact that even small changes to the molecular structure can have on the processing window and transport properties of thin-film devices.

DOI： 10.1039/c9tc04470a

Language：Others   Publishing type：Research paper (scientific journal)  

This journal is © The Royal Society of Chemistry. The synthesis of silafluorene derivatives from aminobiphenyl compounds and dihydrosilanes via a double sila-Friedel-Crafts reaction using a borane catalyst has been achieved. This method is applicable to the synthesis of a variety of silafluorene derivatives, such as multisubstituted silafluorenes, spirosilabifluorenes, and silicon-bridged terphenyl compounds, which are not readily obtained using conventional synthetic methods. In addition, we have demonstrated the transformation of the amino groups in these silafluorene derivatives into other substituents.

DOI： 10.1039/c9cc07692a

Language：Others   Publishing type：Research paper (scientific journal)  

© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Precise control of the selectivity in organic synthesis is important to access the desired molecules. We demonstrate a regiospecific annulation of unsymmetrically substituted 1,2-di(arylethynyl)benzene derivatives for a geometry-controlled synthesis of linear bispentalenes, which is one of the promising structures for material science. A gold-catalyzed annulation of unsymmetrically substituted 1,2-di(arylethynyl)benzene could produce two isomeric pentalenes, but both electronic and steric effects on the aromatics at the terminal position of the alkyne prove to be crucial for the selectivity; especially a regiospecific annulation was achieved with sterically blocked substituents; namely, 2,4,6-trimetyl benzene or 2,4-dimethyl benzene. This approach enables the geometrically controlled synthesis of linear bispentalenes from 1,2,4,5-tetraethynylbenzene or 2,3,6,7-tetraethynylnaphthalene. Moreover, the annulation of a series of tetraynes with a different substitution pattern regioselectively provided the bispentalene scaffolds. A computational study revealed that this is the result of a kinetic control induced by the bulky NHC ligands.

DOI： 10.1002/chem.201902381

Language：Others  

Chemodivergent reaction of azomethine imines and 2H-azirines for the synthesis of nitrogen-containing scaffolds.

DOI： 10.1039/c9ob00740g

Language：Others  

The Combination of Benzaldehyde and Nickel-Catalyzed Photoredox C(sp3)−H Alkylation/Arylation

DOI： 10.1002/anie.201810526

Language：Others  

Dual Gold/Silver Catalysis Involving Alkynylgold(III) Intermediates Formed by Oxidative Addition and C,H-Activation for the Direct Alkynylation of Cyclopropenes

Language：Others  

Light-Induced Gold-Catalyzed Hiyama Arylation: A Coupling Access to Biarylboronates

DOI： 10.1002/anie.201806427

Language：Others  

Silver-Catalyzed CO2 Incorporation

DOI： 10.1002/9783527342822.ch7

Language：Others  

N-Heterocycle-Fused Pentalenes by a Gold-Catalyzed Annulation of Diethynyl-Quinoxalines and -Phenazines

DOI： 10.1002/chem.201803096

Language：Others  

Gold-Catalyzed Regiospecific C−H Annulation of o-Ethynylbiaryls with Anthranils: π-Extension by Ring-Expansion En Route to N-Doped PAHs

DOI： 10.1002/anie.201802445

Language：Others  

New transmetalation reagents for the gold-catalyzed visible light-enabled C(sp or sp2)–C(sp2) cross-coupling with aryldiazonium salts in the absence of a photosensitizer

DOI： 10.1039/c8cc08227h

Language：Others  

Homogeneous catalysed hydrogenation of HMF

DOI： 10.1039/c8gc01025k

Language：English   Publishing type：Research paper (scientific journal)  

Highly substituted 2-cyclopentenones were stereospecifically and regioselectively constructed with high catalytic efficiency through Lewis-acid catalyzed decarboxylative Nazarov cyclization of the cyclic carbonate derivative, which is prepared by reacting the propargyl alcohol with carbon dioxide in the presence of a silver catalyst. The stereochemistry of the 2-cyclopentenone is strictly controlled by the geometry of the alkene in the starting material. This method is applicable for various substrates.

DOI： 10.1002/anie.201705909

Language：English   Publishing type：Research paper (scientific journal)  

The stereoselective synthesis of (E)-bromovinyloxazolidinones was developed by the three-component reaction of propargylic amines, carbon dioxide, and N-bromosuccinimide in the presence of a silver catalyst with a base. Among the bases, a guanidine derivative has a significant effect on this bromination reaction. This catalytic reaction could be applied to various propargylic amines to produce the corresponding bromovinyloxazolidinones in good yields.

DOI： 10.1246/cl.170541

Language：Others  

Gold and carbon dioxide: quo vadis

DOI： 10.1007/s13404-017-0207-y

Language：English  

Silver-catalyzed reactions are some of the important methodologies in organic chemistry. Since 2007, a new application of silver catalysts has been emerging. For the sequential carboxylation and cyclization of alkyne derivatives, such as propargyl alcohols and amines, using carbon dioxide, silver catalysts show significant reactivity under mild conditions unlike other transition metals. These developments have received much attention for the effective utilization of carbon dioxide in organic chemistry to synthesize heterocyclic compounds. Related silver-catalyzed C-C bond forming reactions with carbon dioxide have also provided the synthetic methods of the corresponding carboxylic acid derivatives. In this review, the recent studies of the silver-catalyzed carboxylation reactions using carbon dioxide are described.

DOI： 10.1039/c5cs00895f

Language：English   Publishing type：Research paper (scientific journal)  

C-C bond forming carboxylation, and cyclization: of trimethyl(2-rnethylenbut-3,7yl)silaile derivatives and carbon dioxide was developed. Silver catalysts and CsF promoted the reaction to afford the:corresponding 2-furanone and 2-pyrone derivatives in good-to-high yields. The structure of the 2:furanone was confirmed by single-crystal X-ray crystallography, which revealed that the geometry of the exo-olefin was that of a Z-isomer. When an aromatic ring substituted alkyne was used, 2-furanone derivatives were selectively obtained via 5-exo-dig-cyclization, whereas the reaction of alkyl-substituted alkynes produced 2-pyrone derivatives with high selectivity.

DOI： 10.1021/acs.orglett.5b03023

Language：English   Publishing type：Research paper (scientific journal)  

The silver-catalyzed three-component reaction of propargylic amines, carbon dioxide, and N-iodosuccinimide for the stereoselective synthesis of (E)-iodovinyloxazolidinones was developed. The silver-catalytic system could be applied to various propargylic amines to afford the corresponding iodovinyloxazolidinones in high yields. The structure of the oxazolidinone was confirmed by X-ray structure analysis to be the E-isomer for the geometry of the exo-olefin. The silver-catalyzed cyclization and replacement of silver with the iodine group in the intermediate were thought to be crucial steps.

DOI： 10.1246/cl.150584

Language：English   Publishing type：Research paper (scientific journal)  

Synthesis of Oxazolidin-2-ones by Tandem Cyclization of Propargylic Alcohols and Phenyl Isocyanate Promoted by Silver Catalysts as -Lewis Acids
Highly Z-selective syntheses of oxazolidin-2-ones from propargylic alcohols containing internal alkynes and phenyl isocyanate were achieved by using a combination of silver acetate and N,N-dimethylaminopyridine. The catalytic system was applied to propargylic alcohols containing alkyl-substituted alkyne groups. By considering the results in the presence and absence of an electron-withdrawing group on the aromatics, it was shown that the silver catalyst effectively activates the CC triple bond by acting as a -Lewis acid to produce the corresponding oxazolidinones with high Z-selectivities.

DOI： 10.1055/s-0035-1560263

Language：English   Publishing type：Research paper (scientific journal)  

Silver-catalyzed C-C bond formation with carbon dioxide: significant synthesis of dihydroisobenzofurans
The silver salt catalyzed the C-C bond forming reaction of o-alkynyl-acetophenone derivatives and carbon dioxide. In this reaction, a carbonyl group and a furan skeleton were successively constructed to afford the corresponding dihydroisobenzofuran derivatives.

DOI： 10.1039/c3cc47221c

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/anie.201201399

Language：English   Publishing type：Research paper (scientific journal)  

A silver/DBU catalyst system was developed for the effective synthesis of cyclic carbonate and oxazolidinone from the reaction of CO2 with propargylic alcohols and propargylic amines, respectively, in high yields under mild conditions. It was found that the [3,3]-sigmatropic Meyer Schuster-type rearrangement of the propargylic alcohol was mediated by CO2 in DMF to afford the corresponding alpha,beta-unsaturated carbonyl compounds in high yields. The silver salt combined with the chiral Schiff base ligand could be applied to enantioselective chemical CO2 incorporation into various bispropargylic alcohols to produce the corresponding cyclic carbonate in high yields with high enantioselectivity. The absolute configuration was determined by VCD spectroscopy as well as by X-ray analysis. These products were found to be active for the aminolysis reaction to afford the corresponding carbamate derivatives in high yields without any loss of optical purity.

DOI： 10.1246/bcsj.20110078

Event date： 2024.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：千葉   Country：Japan  

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Event date： 2023.3

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Venue：東京理科大学　野田キャンパス   Country：Japan  

Event date： 2023.3

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Venue：東京理科大学　野田キャンパス   Country：Japan  

Event date： 2022.11

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Venue：静岡県清水文化会館（マリナート）   Country：Japan  

Event date： 2022.9

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Venue：オンライン開催   Country：Japan  

Event date： 2022.7

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Venue：北九州国際会議場   Country：Japan  

Event date： 2022.6

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Country：Japan  

Event date： 2022.4

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2022.4

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Venue：オンライン開催   Country：Japan  

Event date： 2022.4

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Venue：オンライン開催   Country：Japan  

Event date： 2022.4

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Venue：オンライン開催   Country：Japan  

Event date： 2022.4

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Venue：オンライン開催   Country：Japan  

Event date： 2021.6

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Venue：九州大学 伊都キャンパス　椎木講堂   Country：Japan  

Event date： 2021.5

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Venue：オンライン   Country：Japan  

Event date： 2021.5

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Country：Japan  

Event date： 2021.3

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Event date： 2020.10

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Event date： 2020.3

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Venue：東京理科大学　野田キャンパス   Country：Japan  

Event date： 2020.3

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Venue：東京理科大学　野田キャンパス   Country：Japan  

Event date： 2020.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京理科大学　野田キャンパス   Country：Japan  

Event date： 2020.3

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Venue：東京理科大学　野田キャンパス   Country：Japan  

Event date： 2020.1

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Venue：フェニックス・シーガイア・リゾート（宮崎市）   Country：Japan  

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Venue：北九州国際会議場(北九州市)   Country：Japan  

Event date： 2019.11

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Venue：北海道大学   Country：Japan  

Event date： 2019.7

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Country：Germany