Kei Usui

Differential muscle activation patterns and kinematics during the nordic hamstring exercise and the maximum-speed single-leg bridge test

Yuto Sano, Masashi Kawabata, Bas Van Hooren, Masaki Murase et autres

The Nordic Hamstring Exercise (NHE) is widely used to assess hamstring strain injury (HSI) risk, but the joint angles and resulting hamstring muscle-tendon unit (MTU) lengths are dissimilar to sprinting, which may limit sensitivity. The Maximum-Speed Single-Leg Bridge Test (MS-SLBT) was developed …

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Concerted Hydrosilylation Catalysis by Silica-Immobilized Cyclic Carbonates and Surface Silanols

Shingo Hasegawa, K. Nakamura, K. Soga, Kei Usui et autres

High Resolution Image Download MS PowerPoint Slide Developing a method for creating a novel catalysis of organic molecules is essential because of the growing interest in organocatalysis. In this study, we found that cyclic carbonates immobilized on a nonporous or mesoporous silica …

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Cover Feature: Rhodium–Iodide Complex on a Catalytically Active SiO2 Surface for One‐Pot Hydrosilylation–CO2 Cycloaddition (Chem. Eur. J. 5/2022)

Kei Usui, Yuichi Manaka, Wang‐Jae Chun, Ken Motokura

Surface Rh species with three iodine atoms showed a high catalytic activity for the hydrosilylation of terminal olefins. The picture indicates three iodides with an ammonium cation “tent” coordinate to Rh, and the hydrosilylation reaction occurs at the electron-rich Rh site. Next, …

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Rhodium–Iodide Complex on a Catalytically Active SiO2 Surface for One‐Pot Hydrosilylation–CO2 Cycloaddition

Kei Usui, Yuichi Manaka, Wang‐Jae Chun, Ken Motokura

Abstract In this study, a novel Rh–iodide complex was synthesized through a surface reaction between an immobilized Rh cyclooctadiene complex and alkylammonium iodide (N+I−) on SiO2. In the presence of ammonium cations, the SiO2‐supported Rh–iodide complex could be effectively used for the …

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Correction to “Enhanced Catalysis Based on the Surface Environment of the Silica-Supported Metal Complex”

Ken Motokura, Siming Ding, Kei Usui, Yuanyuan Kong

ADVERTISEMENT RETURN TO ISSUEPREVCorrectionNEXTORIGINAL ARTICLEThis notice is a correctionCorrection to "Enhanced Catalysis Based on the Surface Environment of the Silica-Supported Metal Complex"Ken Motokura*Ken MotokuraMore by Ken Motokurahttps://orcid.org/0000-0002-0066-5139, Siming DingSiming DingMore by Siming Ding, Kei UsuiKei UsuiMore by Kei Usui, and Yuanyuan KongYuanyuan …

Enhanced Catalysis Based on the Surface Environment of the Silica-Supported Metal Complex

Ken Motokura, Siming Ding, Kei Usui, Yuanyuan Kong

Silica-supported metal complex catalysts have been developed and used for organic transformations. The surface environment around the supported metal complex enhances the catalysis based on a unique surface effect. The design of the linker ligand structure induces the formation of a highly …

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シリカ固定化多機能触媒の構造解析とシリルカーボネートのワンポット合成への展開

慧 臼井, Kei Usui, 恭吾 前田, Kyogo Maeda et autres

シリカ固定化環状カーボネート触媒によるカルボニル化合物のヒドロシリル化反応

圭佑 中村, Keisuke Nakamura, 慧 臼井, Kei Usui et autres

Characterization of silica-supported multifunctional catalyst and its use for one-pot synthesis of silyl carbonates

Kei Usui

機能集積型不均一触媒によるワンポットでのヒドロシリル化-環状カーボネート形成反応

慧 臼井, Kei Usui, 昂大 宮下, Kohdai Miyashita et autres

Multifunctional Catalytic Surface Design for Concerted Acceleration of One-Pot Hydrosilylation−CO2 Cycloaddition

Kei Usui, Kyogo Maeda, 雄一 眞中, Yuichi Manaka et autres

Multifunctional Catalytic Surface Design for Concerted Acceleration of One-Pot Hydrosilylation–CO2 Cycloaddition

Kei Usui, Kodai Miyashita, Kyogo Maeda, Yuichi Manaka et autres

Silica-supported Rh-ammonium iodide catalyst showed high performance for hydrosilylation–CO 2 cycloaddition reaction sequences. The catalyst was prepared by surface grafting of Rh and the silane-coupling reaction of the ammonium iodide moiety. The acceleration of each catalytic reaction was realized due to the …

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