1,753,973 research outputs found
A Highly Stereoselective Claisen-Sakurai Approach to Densely Functionalized Cyclopentenols
No full textThe formation of highly substitiuted cyclopentenols was developed using a Claisen-Sakurai reaction. Both elements of the reaction can be performed in a one-pot sequence that provides the corresponding cyclized products in high stereoselectivity. The stereochemical outcome is defined by a combination of Claisen stereospecificity and stereoelectronic effects in the Sakurai cyclization that promotes reactivity via a syn-SE’ antiperiplanar transition-state. This was determined by examination of the product stereochemistry and through detailed DFT analysis
Oral history interview with Ayaka Sakurai, 2012 June 5
No full textAyaka Sakurai works with the Providence Little Company of Mary Medical Center to help hibakusha receive the medical care they need, including the biannual medical checkups by doctors from Hiroshima. She talks about moving to California and describes how she met her husband, a doctor named Yutaka Sakurai. She describes how she became involved in using her time and money, as well as her language skills, for volunteer work. She talks about her husband's family's long history with the U.S., beginning with his grandfather, and describes her husband's history of working in California as the head of the Providence Ningen Dock Center. Ayaka's husband's older brother went into Hiroshima after the bombing and was exposed to radiation, leading to cancer later in his life, and although her husband couldn't treat his own brother, he feels that by treating other hibakusha he is helping in his own way
Improving backward stability of Sakurai-Sugiura method with balancing technique in polynomial eigenvalue problem
No full textsummary:One of the most efficient methods for solving the polynomial eigenvalue problem (PEP) is the Sakurai-Sugiura method with Rayleigh-Ritz projection (SS-RR), which finds the eigenvalues contained in a certain domain using the contour integral. The SS-RR method converts the original PEP to a small projected PEP using the Rayleigh-Ritz projection. However, the SS-RR method suffers from backward instability when the norms of the coefficient matrices of the projected PEP vary widely. To improve the backward stability of the SS-RR method, we combine it with a balancing technique for solving a small projected PEP. We then analyze the backward stability of the SS-RR method. Several numerical examples demonstrate that the SS-RR method with the balancing technique reduces the backward error of eigenpairs of PEP
Dorothy Sakurai, 1942
No full textBack of photograph: Dorothy Sakurai Center Mrs. Claire Sprague\u27s Class French Camp School 1942https://scholarlycommons.pacific.edu/sprague/1023/thumbnail.jp
A filter diagonalization for generalized eigenvalue problems based on the Sakurai–Sugiura projection method
No full textAbstractThe Sakurai–Sugiura projection method, which solves generalized eigenvalue problems to find certain eigenvalues in a given domain, was reformulated by using the resolvent theory. A new interpretation based on filter diagonalization was given, and the corresponding filter function was derived explicitly. A block version of the method was also proposed, which enabled not only resolution of degenerated eigenvalues, but also an improvement in numerical accuracy. Three numerical examples were provided to illustrate the method
Recent Developments in the Catalytic Enantioselective Sakurai Reaction
No full textInternational audienceThe Sakurai reaction constitutes a valuable tool for carbon-carbon bond formation. The use of nontoxic allylic reagents as well as the atom economy of the global process has prompted the development of enantioselective (aza)-variants based on the use of chiral organo-and metal catalysts. This review collects the recent developments in catalytic enantioselective Sakurai reactions published since the beginning of 2011, including methodologies based on the use of chiral organocatalysts, metal/boron catalysts and multicatalyst systems. It is divided into three parts, dealing successively with enantioselective organocatalytic (aza-)Sakurai reactions, enantioselective metal/boron-catalyzed Sakurai reactions, and enantioselective multicatalyzed (aza-)Sakurai reactions. It shows that, although still widely developed with aromatic aldehydes, the enantioselective catalytic Sakurai reaction has considerably matured in the last decade.</div
Highly diastereoselective silyl-modified Sakurai multicomponent reaction
No full textHighly diastereoselective silyl-modified Sakurai multicomponent reactio
Oral history interview with Fred Yutaka Sakurai, 2012 June 7
No full textFred Yutaka Sakurai was born in Tokyo and wanted to become a doctor to help people. He came to the U.S. in 1953 as an exchange student. He is the third generation of his family to come to the U.S. He talks about his grandfather's trips to the U.S. to buy warships on behalf of the navy and his father's education in the U.S. after deciding to become a doctor following having his appendix taken out. He describes how his brother went into Hiroshima after the bombing, making him a hibakusha. He talks about his experiences when he first arrived in the U.S. and his experiences in the Army Medical Corps. He describes the circumstances that led him to work with hibakusha, including helping with the biennial medical check-ups and his involvement in groups such as Japanese Community Health, Inc. He thinks that the U.S. government should take responsibility for the bombing and help with caring for hibakusha. He and his wife talk about the kinds of volunteers that come to help and the role that women play in the medical profession
Hosomi—Sakurai Reactions of Silacyclic Allyl Silanes.
No full textSubstituted silacyclohexenes, generated through silene–diene [4 + 2] cycloaddition reactions, undergo Lewis acid promoted Sakurai type reactions with acetals to afford, following oxidation of the resultant fluorosilane, 1,4-diols with four contiguous chiral centres
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