Kazuya Yamaguchi 교수

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTMg−Al Mixed Oxides as Highly Active Acid−Base Catalysts for Cycloaddition of Carbon Dioxide to EpoxidesKazuya Yamaguchi, Kohki Ebitani, Tomoko Yoshida, Hisao Yoshida, and Kiyotomi KanedaView Author Information Department of Chemical Science and Engineering Graduate School of Engineering Science Osaka University,1-3 Machikaneyama, Toyonaka Osaka 560-8531, Japan Center for Integrated Research in Science and Engineering, Nagoya University Nagoya 464

Round and round it goes! A supported ruthenium catalyst, easily prepared by treatment of RuCl3 with γ-Al2O3, is an efficient heterogeneous catalyst for the oxidations of alcohols with 1 atm of molecular oxygen or air without any additives (see scheme). The spent catalyst was recyclable without an appreciable loss of the catalytic activity and selectivity for the oxidation. The Ru/Al2O3 system had high catalytic activities for the oxidation of activated and non-activated alcohols with only 1 atm

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTCreation of a Monomeric Ru Species on the Surface of Hydroxyapatite as an Efficient Heterogeneous Catalyst for Aerobic Alcohol OxidationKazuya Yamaguchi, Kohsuke Mori, Tomoo Mizugaki, Kohki Ebitani, and Kiyotomi KanedaView Author Information Department of Chemical Science and Engineering Graduate School of Engineering Science Osaka University, 1-3 Machikaneyama Toyonaka, Osaka 560-8531, Japan Cite this: J. Am. Chem. Soc. 2000, 122, 29, 7144–7145P

An inexpensive supported ruthenium catalyst (Ru/Al2O3) can be used to convert a broad range of primary (see scheme) and secondary amines into the corresponding nitriles and imines in high yields using either dioxygen or air as oxidants. The catalyst can be recycled and reused with no detectable loss of ruthenium and without an observed reduction in catalytic activity. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2003/z50779_s.pdf

The Ru/Al(2)O(3) catalyst was prepared by modification of the preparation of Ru(OH)(3).n H(2)O. The present Ru/Al(2)O(3) catalyst has high catalytic activities for the oxidations of activated, nonactivated, and heterocyclic alcohols, diols, and amines at 1 atm of molecular oxygen. Furthermore, the catalyst could be reused seven times without a loss of catalytic activity and selectivity for the oxidation of benzyl alcohol. A catalytic reaction mechanism involving a ruthenium alcoholate species an

Peroxotungstate immobilized on ionic liquid-modified SiO2 is capable of heterogeneously epoxidizing a wide range of olefins with the maintenance of the catalytic activity of homogeneous analogue. The epoxidation was immediately stopped by the removal of the catalyst, and no tungsten species could be found in the filtrate after the removal of the catalyst. These results can rule out any contribution to the observed catalysis from the tungsten species that leached into the reaction solution, and t

Polyoxometalates (POMs), which are anionic metal oxide clusters, have recently attracted considerable attention as photocatalysts because of their unique photoinduced charge-transfer properties, redox properties, acid–base properties, and reactivities. In this Review, we present a summary of recent developments in POM photocatalysis for organic synthesis. Various organic functional group transformations can be selectively induced by photoirradiation in the presence of catalytic amounts of suitab

A broad range of amides is accessible in excellent yield (>99 %) by hydration of the corresponding nitriles in water in the presence of the supported ruthenium catalyst Ru(OH)x/Al2O3 (see scheme). For example, the industrially important conversion of acrylonitrile into acrylamide was achieved in quantitative yield and better than 99 % selectivity. The catalyst can be reused without loss of catalytic activity and selectivity. Supporting information for this article is available on the WWW under h

Mix and match: A tungsten–tin mixed hydroxide (W–Sn hydroxide), prepared by the simple coprecipitation method, acts as a reusable heterogeneous catalyst for the dehydration of various aldoximes to the corresponding nitriles (see scheme, top). Furthermore, the W–Sn hydroxide catalyst could be applied to the direct one-pot synthesis of nitriles from hydroxylamine and the corresponding aldehydes (see scheme, bottom).

In the presence of a manganese oxide based octahedral molecular sieve (OMS-2), a range of primary amides could be synthesized directly from primary alcohols and ammonia. The observed catalysis was heterogeneous, and the recovered catalyst could be reused many times without an appreciable loss of its catalytic performance.

The N-alkylation of ammonia (or its surrogates, such as urea, NH(4)HCO(3), and (NH(4))(2)CO(3)) and amines with alcohols, including primary and secondary alcohols, was efficiently promoted under anaerobic conditions by the easily prepared and inexpensive supported ruthenium hydroxide catalyst Ru(OH)(x)/TiO(2). Various types of symmetrically and unsymmetrically substituted "tertiary" amines could be synthesized by the N-alkylation of ammonia (or its surrogates) and amines with "primary" alcohols.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDirect observation of the push effect on the oxygen-oxygen bond cleavage of acylperoxoiron(III) porphyrin complexesKazuya Yamaguchi, Yoshihito Watanabe, and Isao MorishimaCite this: J. Am. Chem. Soc. 1993, 115, 10, 4058–4065Publication Date (Print):May 1, 1993Publication History Published online1 May 2002Published inissue 1 May 1993https://pubs.acs.org/doi/10.1021/ja00063a026https://doi.org/10.1021/ja00063a026research-articleACS PublicationsRequest reu

RuCl3 successfully reacts with the lacunary silicotungustate in organic medium, giving a Ru3+-substituted silicotungstate that can act as a heterogeneous catalyst for the oxidation of a wide range of alkanes and alcohols using 1 atm of molecular oxygen as the sole oxidant.

The development of novel systems for metal-organic architectures is an attractive research field because they are fascinating materials with unexplored functions. Lacunary polyoxometalates (POMs) offer structurally well-defined coordination sites with various coordination directions and numbers in addition to the designable properties; thus, lacunary POMs are ideal building blocks for inorganic-organic architectures. However, their utilization is currently limited by their low stability and diff

The basic layered hydrotalcites have been used as catalysts for the epoxidation of alpha,beta-unsaturated ketones in heterogeneous reaction media using hydrogen peroxide as an oxidant. A wide variety of alpha,beta-unsaturated ketones were oxidized to the corresponding epoxyketones in excellent yields under mild reaction conditions. For example, 2-cyclohexen-1-one gave 2,3-epoxycyclohexanone in 91% yield at 40 degrees C for 5 h with high efficiency in hydrogen peroxide. The catalytic activity of