東京工業大学 · Materials Science
이wasawa 교수의 연구실은 이산화탄소 활용 화학 반응을 중심으로 한 촉매 반응 개발에 집중하고 있습니다. 특히, C–H 결합 활성화, 광촉매를 이용한 탄소디옥사이드의 효율적 이용, 금속-탄소 결합을 통한 새로운 고리형 화합물 합성 등에 있어 독창적인 반응 메커니즘을 제시하고 있습니다. 다이아몬드형 구조의 자기조립 시스템과 같은 새로운 유기촉매 설계를 통해 환경 친화적인 합성 전략을 모색하고 있습니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTGeneration and Reaction of Metal-Containing Carbonyl Ylides: Tandem [3+2]-Cycloaddition−Carbene Insertion Leading to Novel Polycyclic CompoundsNobuharu Iwasawa, Masahide Shido, and Hiroyuki KusamaView Author Information Department of Chemistry, Tokyo Institute of Technology O-okayama, Meguro-ku, Tokyo 152−8551, Japan Department of Chemistry, Graduate School of Science The University of Tokyo, Hongo, Bunkyo-ku Tokyo 113-0033, Japan Cite this: J. A
Direct carboxylation of simple arenes under atmospheric pressure of CO2 is achieved through a rhodium-catalyzed C-H bond activation without the assistance of a directing group. Various arenes such as benzene, toluene, xylene, electron-rich or electron-deficient benzene derivatives, and heteroaromatics are directly carboxylated with high TONs.
A visible light driven catalytic cycle for hydrocarboxylation of alkenes with CO<sub>2</sub> was established using a combination of a Rh(i) complex as a carboxylation catalyst and [Ru(bpy)<sub>3</sub>]<sup>2+</sup> (bpy = 2,2'- bipyridyl) as a photoredox catalyst. Two key steps, the generation of Rh(i) hydride species and nucleophilic addition of π-benzyl Rh(i) species to CO<sub>2</sub>, were found to be mediated by light.
We report dynamic self-assembly utilizing boronic ester formation with special emphasis on the following six points: (1) two kinds of host molecule are constructed spontaneously with benzene or toluene as the guest molecule under neutral conditions simply by mixing a di(boronic acid) and a bis(1,2-diol) in methanol; (2) the precipitation process is essential for this selective preparation of host molecules; (3) recognition of the enantiomers of bis(1,2-diol) is achieved during host formation in
Novel bidentate amidines were designed and synthesized as easily available electron-donating N-ligands for Ni0-mediated coupling of carbon dioxide with alkynes or allenes, and high regioselectivity was achieved even for the carboxylation of aryl substituted internal alkynes.
[reaction: see text] A highly efficient method for the cyclopentene annulation onto alpha,beta-unsaturated ketones is described. Indium-mediated 1,4-propargylation onto alpha,beta-unsaturated ketones in the presence of tert-butyldimethylsilyl triflate and dimethyl sulfide gives the 6-siloxy-5-en-1-yne derivatives, which undergo W(CO)(5)(L)-catalyzed 5-endo-dig cyclization to give the corresponding cyclopentene derivatives in good yield.
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTReactions of Propargyl Metallic Species Generated by the Addition of Alkynyllithiums to Fischer-Type Carbene ComplexesNobuharu Iwasawa, Katsuya Maeyama, and Masatoshi SaitouView Author Information Department of Chemistry, Graduate School of Science The University of Tokyo Hongo, Bunkyo-ku, Tokyo 113, Japan Cite this: J. Am. Chem. Soc. 1997, 119, 6, 1486–1487Publication Date (Web):February 12, 1997Publication History Received27 June 1996Published
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTNovel Synthesis of Pentacarbonylbenzopyranylidenetungsten(0) Complexes and Their Diels−Alder Reaction with Electron-Rich AlkenesNobuharu Iwasawa, Masahide Shido, Katsuya Maeyama, and Hiroyuki KusamaView Author Information Department of Chemistry, Tokyo Institute of Technology O-okayama, Meguro-ku, Tokyo, 152-8551 Department of Chemistry, Graduate School of Science The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-0033 Cite this: J. Am. Chem.
Abstract Various β-carbonyl radicals are generated oxidatively from cyclopropanol derivatives by the use of manganese(III) 2-pyridinecarboxylate (Mn(pic)3). These β-carbonyl radicals react with electron-rich olefins such as conjugated silyl enol ethers, a ketene thioacetal, a ketene dithioacetal, and a vinyl ether intermolecularly to give crossed-addition products in good yield. Furthermore, the combined use of Mn(pic)3 and tributylhydridotin makes it possible to carry out the 1 : 1 addition rea
A highly useful method for five- and six-membered ring annulation onto alpha,beta-unsaturated ketones is described. 1,4-Addition of propargylmalonate to alpha,beta-unsaturated ketones in the presence of silyl triflate gives 7-siloxy-6-en-1-yne derivatives in good yield. W(CO)(5).L-catalyzed cyclization of these substrates can be induced to give preferentially either exo- or endo-cyclized products in good yield simply by changing the reaction solvent. [reaction: see text]
