巻号一覧
61 巻, 11 号
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Shunichi Fukuzumi2003 年 61 巻 11 号 p. 1046-1055
発行日: 2003/11/01
公開日: 2009/11/13
ジャーナル フリーNew paradigm of electron transfer chemistry in organic reactions is described, making it possible to finely control electron transfer reactions of organic molecules as nature has developed to a high degree of perfection in biological systems raging from photosynthesis to respiration. Important approaches to design and to control organic electron transfer reactions are based on the Marcus theory of electron transfer with weak interactions. New approaches also include electron transfer reactions accompanied by transient chemical bonding with third components such as Lewis acids which can act as promoters to accelerate organic electron transfer reactions. Synthetic application of such new paradigm of electron transfer chemistry in organic reactions is demonstrated by a variety of examples of overall organic chemical transformations which involve Lewis acid-promoted electron transfer processes as the rate-determining step.抄録全体を表示PDF形式でダウンロード (1948K) -
Yasutaka Ishii, Satoshi Sakaguchi2003 年 61 巻 11 号 p. 1056-1064
発行日: 2003/11/01
公開日: 2009/11/13
ジャーナル フリーInnovative carbon radical generation from hydrocarbons through a catalytic process under mild conditions has been achieved by the use of N-hydroxyphthalimide (NHPI) as a catalyst. This method can be successfully applied to a wide variety of functionalizations of hydrocarbons. Thus, alkanes are converted into alcohols, ketones, carboxylic acids, nitro alkanes and alkyl sulfonic acids through alkyl radicals generated by the action of NHPI. Hydroxysilylation was first performed by the addition of hydrosilanes and oxygen to alkenes bearing electron-withdrawing substituents. A new approach to oxyalkylation based on the concomitant addition of carbon radicals derived from alkanes or alcohols and molecular oxygen to alkenes or alkynes has been described.抄録全体を表示PDF形式でダウンロード (1343K) -
Miwako Mori, Yuji Kozawa, Masanori Takimoto2003 年 61 巻 11 号 p. 1065-1072
発行日: 2003/11/01
公開日: 2009/11/13
ジャーナル フリーCarbapenams, which are important β-lactam antibiotics and have highly strained 4-5 fused-membered ring systems, could be synthesized using ruthenium- or palladium-catalyzed cyclization.抄録全体を表示PDF形式でダウンロード (1287K) -
Shuji Kanemasa2003 年 61 巻 11 号 p. 1073-1080
発行日: 2003/11/01
公開日: 2009/11/13
ジャーナル フリーThis article describes a new synthetic methodology developed in our institute, which produces enantiomers in the reactions using strongly coordinating nucleophiles under the catalysis of torelant chiral Lewis acid. The nickel (II) aqua complexes derived from DBFOX chiral ligand can successfully catalyze the conjugate addition reactions of thiols. Even under double catalytic conditions using catalytic amounts of both amines and the DBFOX - nickel (II) complexes, Michael addition reactions of active methylene compounds such as malononitrile and nitromethane can be effectively activated.抄録全体を表示PDF形式でダウンロード (1570K) -
Makoto Nakajima2003 年 61 巻 11 号 p. 1081-1087
発行日: 2003/11/01
公開日: 2009/11/13
ジャーナル フリーNew enantioselective reactions catalyzed by chiral N-oxides or chiral N-oxide-metal complexes are discussed. Enantioselective allylations of aldehydes with allyltrichlorosilanes, aldol reactions with trichlorosilyl enol ethers, and epoxide-opening reactions with tetrachlorosilane were accomplished by using chiral bipyridine N, N'-dioxide derivatives as catalysts. In these reactions, hexacoordinate silicate intermediates played pivotal roles in the enantioselection. Furthermore, the N-oxides were efficient chiral ligands for the enantioselective conjugate addition of thiols catalyzed by cadmium complexes and Michael addition of β-keto esters catalyzed by scandium complexes.抄録全体を表示PDF形式でダウンロード (1187K) -
Yoshimitsu Nagao, Shigeki Sano2003 年 61 巻 11 号 p. 1088-1098
発行日: 2003/11/01
公開日: 2009/11/13
ジャーナル フリーVarious kinds of new reactions based on allenylic molecular structure characteristics have been described. Specifically, mild alkaline hydrolysis of diethyl α-acetylamino (or methoxy) -α-alkynylmalonates generates conjugated allenyl esters which promote 5-endo-mode heterocyclic cyclization giving trisubsutituted oxazoles, SH-enzyme inhibition, new chiral pyrrolinones (cathepsin B inhibitors) formation, and Myers-type biradical aromatization in a cascade reaction manner. Systematic ortho vicinal-endo-mode-, geminal spiro-endo-mode-, and meta ansa-endo-mode-cyclization reactions have been accomplished by using numerous conjugated allenyl ketones and Lewis acids. Base-mediated and palladium (0) -catalyzed cascade heterocyclic and carbocyclic ring-expansion reactions have been achieved by using hydroxy-substituted allenyl cyclic compounds.抄録全体を表示PDF形式でダウンロード (1764K) -
Makoto Kuramoto, Hirokazu Arimotot, Daisuke Uemura2003 年 61 巻 11 号 p. 1099-1105
発行日: 2003/11/01
公開日: 2009/11/13
ジャーナル フリーIn our continuing search for bioactive substances from marine organisms, novel alkaloids were isolated. The structures and functions of these marine alkaloids are described here.
Pinnatoxins and pteriatoxins, potent shellfish poisons, were purified from the Okinawan bivalve Pinna muricata. Pinnatoxins activate Ca2+ channels. Halichlorine was isolated from the marine sponge Halichondria okadai. This compound inhibits the induction of VCAM-1. Drugs that block VCAM-1 may be useful for treating coronary artery diseases, angina, and noncardiovascular inflammatory diseases. Pinnaic acids, which are cPLA2 inhibitors, were also obtained from P. muricata. Interestingly, the structures of pinnaic acids are closely related to that of halichlorine. Norzoanthamine hydrochloride, isolated from the colonial zoanthid Zoanthus sp., suppresses decreases in bone weight and strength in ovariectomized mice, and could be a good candidate for an osteoporotic drug. Aburatubolactams, inhibitors of superoxide anion generation, were isolated from Streptomyces sp.抄録全体を表示PDF形式でダウンロード (1432K) -
Juzo Nakayama2003 年 61 巻 11 号 p. 1106-1115
発行日: 2003/11/01
公開日: 2009/11/13
ジャーナル フリー3, 4-Di-tert-butylthiophene 1-oxide (1) and 1-imide (2), which possess anti- and syn-π-faces with respect to the S=X bond (X= O or NTs), provide an excellent model system to investigate π-face selectivity in a variety of addition reactions. Diels-Alder reactions of 1, including inverse electron-demand and hetero Diels-Alder reactions, all take place selectively at the syn-π-face of 1 with respect to the S=O bond in high yields under mild conditions. The observed π-face selectivity can be well explained by the difference in conformational changes that are brought about at the transition states for anti- and syn-π-face additions. Even 1, 3-dipolar cycloadditions of 1 take place predominantly at the syn-π-face to the S=O bond. Diels-Alder reactions of 2 also occur at the syn-π-face with respect to the S=NTs bond. The Diels-Alder reaction of 2 with PTAD provides the first synthesis of an S-unoxidized 1, 2-thiazetidine derivative. The addition of bromine to 1, though not π-face selective, occurs in a 1, 4-cis mode exclusively. Only Michael additions to 1 take place at the anti-π-face probably as a result controlled by nonequivalent orbital extension of π-LUMO.抄録全体を表示PDF形式でダウンロード (1502K) -
Masaaki Yoshifuji2003 年 61 巻 11 号 p. 1116-1123
発行日: 2003/11/01
公開日: 2009/11/13
ジャーナル フリーPreparation and characterization of sterically protected diphosphinidenecyclobutenes bearing two phosphorus atoms of coordination number 2 are described from the viewpoint of development of a novel type of bidentate ligand for transition metal complexes. They form the complexes with group 6 metals such as chromium, molybdenum, and tungsten, and group 10 metals such as palladium and platinum. Some of them can be used as a catalyst for synthetic reactions such as cross-coupling of the Sonogashira type, polymerization of ethylene, dehydrogenative hydrosilylation of ketones, hydroamination of 1, 3-butadienes, and direct alkylation or amination of allylic alcohols.抄録全体を表示PDF形式でダウンロード (1351K) -
Yasushi Nakayama, Makoto Mitani, Hideki Bando, Terunori Fujita2003 年 61 巻 11 号 p. 1124-1137
発行日: 2003/11/01
公開日: 2009/11/13
ジャーナル フリーThe olefin polymerization behavior of bis (phenoxy-imine) group 4 transition metal complexes (named FI Catalysts) is described. In association with methylalumoxane (MAO) or iBu3Al/Ph3CB (C6F5)4, FI Catalysts display unique catalytic performance and have created a variety of polyolefin-based materials. For example, FI Catalysts are capable of producing vinyl-terminated low molecular weight polyethylenes (Mv < 2000), well-defined multimodal polyethylenes, ultra-high molecular weight amorphous ethylene-propylene copolymers (Mw > 10, 000, 000), highly syndiotactic polypropylenes with extremely high peak melting temperatures (Tm > 150°C), various block copolymers from ethylene and propylene and stereo- and regio-irregular high molecular weight poly (1-hexene)s. Many of these polymers were unavailable prior to the development of FI Catalysts. Additionally, studies on new cocatalysts for FI Catalysts have resulted in the discovery of FI Catalyst/MgCl2-based compound systems, which represent the first examples of MAO- and fluoroarylborate-free highly active single-site catalyst systems based on group 4 transition metal complexes.抄録全体を表示PDF形式でダウンロード (3070K)
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