Author
Yasushi Sugiura
Bio: Yasushi Sugiura is an academic researcher from Chiba University. The author has contributed to research in topics: Allylic rearrangement & Reformatsky reaction. The author has an hindex of 4, co-authored 5 publications receiving 567 citations.
Papers
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TL;DR: The amalgame de cerium as discussed by the authors is a reactif efficace for the preparation chimioselective d'alcools homoally liques a partir d'halogenures allyliques and de composes carbonyles.
Abstract: L'amalgame de cerium est un reactif efficace pour la preparation chimioselective d'alcools homoallyliques a partir d'halogenures allyliques et de composes carbonyles. Ce meme reactif est utilise dans des reactions de type Reformatsky. Les reactifs organiques du Ce(III) generes par reaction d'organolithiens avec CeI 3 ou CeCl 3 sont moins basiques que les organolithiens et les reactifs de Grignard et reagissent avec divers composes carbonyles
317 citations
TL;DR: Organocerium reagents, prepared from organolithiums and anhydrous cerium (III) chloride, react cleanly with easily enolizable ketones to afford the addition products in good to excellent yields as discussed by the authors.
233 citations
TL;DR: In this article, a 1,2-addition of organocerium reagents to α,β-unsaturated carbonyl compounds was proposed. But this selective 1 2 -addition was considered to proceed through a polar pathway.
21 citations
TL;DR: In this article, a mechanistic view of the reaction with α,β-unsaturated carbonyl compounds was studied from a point of view by the use of (E)- and (Z)-1-(4′-methoxyphenyl)-3-phenyl-2-propen-1-ones and 4,4-ethylenedioxy-2,6-dimethyl -2,5-cyclohexadienone as the probe compounds.
9 citations
TL;DR: In this paper, Grignard et al. described Grignards as a "Grignard" character, and showed how to use a grignard-style sword to defend against bandits.
Abstract: 無水塩化セリウム(III)に有機リチウム化合物を反応させ,有機セリウム反応剤を調製した。この反応剤は Grignard 反応剤や有機リチウム反応剤とくらべて塩基性が低く,2-テトラロンや1,3-ジフェニル-2-プロパノンのようなエノール化しやすいケトンとも円滑に反応し,対応する求核付加物を高収率で与えた。またリチウムエノラートに無水塩化セリウムを反応させて得られるセリウムエノラートは,立体的にかさ高いアルデヒドやケトンとも反応し,アルドールを良好な収率で与えた。
3 citations
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TL;DR: In this paper, the authors describe the development of rare-earth-alkali metal complexes such as LnM3tris(binaphthoxide) complexes (LnMB, Ln = rare earth metal, M = alkali metal), which are readily prepared from corresponding rare earth trichlorides or rare earth isopropoxides, and their application to catalytic asymmetric synthesis.
Abstract: This review focuses on a new concept in catalytic asymmetric reactions that was first realized for the use of heterobimetallic complexes. As these heterobimetallic complexes function as both a Bronsted base and as a Lewis acid, just like an enzyme, they make possible a variety of efficient catalytic asymmetric reactions. This heterobimetallic concept should prove to be applicable to a variety of new asymmetric catalyses. The first part of this review describes the development of rare-earth–alkali metal complexes such as LnM3tris(binaphthoxide) complexes (LnMB, Ln = rare-earth metal, M = alkali metal), which are readily prepared from the corresponding rare-earth trichlorides or rare-earth isopropoxides, and their application to catalytic asymmetric synthesis. By using a catalytic amount of LnMB complexes several asymmetric reactions proceed efficiently to give the corresponding desired products in up to 98% ee: LnLB-catalyzed asymmetric nitroaldol reactions (L = Li), LnSB-catalyzed asymmetric Michael reactions (S Na), and LnPB-catalyzed asymmetric hydrophosphonylations of either imines or aldehydes (P K). Applications of these heterobimetallic catalysts to the syntheses of several biologically and medicinally important compounds are also described. Spectral analyses and computational simulations of the asymmetric reactions catalyzed by the heterobimetallic complexes reveal that the two different metals play different roles to enhance the reactivity of both reaction partners and to position them. From mechanistic considerations, a useful activation of the heterobimetallic catalyses was realized by addition of alkali metal reagents. The second part describes the development of another type of heterobimetallic catalysts featuring Group 13 elements such as Al and Ga as the central metal. Among them, the AlLibis(binaphthoxide) complex (ALB) is an effective catalyst for asymmetric Michael reactions, tandem Michael–aldol reactions, and hydrophosphonylation of aldehydes.
586 citations
485 citations
431 citations
392 citations
TL;DR: The recent findings in metal-catalyzed reductive coupling reactions of aryl halides and (pseudo)halides with carbonyl-type compounds are summarized, with particular emphasis on the mechanistic interpretation of the results and future aspects of this area of expertise.
Abstract: Metal-catalyzed reductive coupling reactions of aryl halides and (pseudo)halides with carbonyl-type compounds have undergone an impressive development within the last years. These methodologies have shown to be a powerful alternate strategy, practicality aside, to the use of stoichiometric, well-defined, and, in some cases, air-sensitive organometallic species. In this Minireview, the recent findings in this field are summarized, with particular emphasis on the mechanistic interpretation of the results and future aspects of this area of expertise.
337 citations