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Volume 47, Issue 3
Displaying 1-9 of 9 articles from this issue
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Diastereofacial Control in the Nucleophilic Addition to Carbonyl CompoundsTamotsu FUJISAWA, Yutaka UKAJI1989 Volume 47 Issue 3 Pages 186-199
Published: March 01, 1989
Released on J-STAGE: January 22, 2010
JOURNAL FREE ACCESSThe ever advancing development of chemical reactions has initiated enormous progress towards the stereoselective reactions. In almost cases, however, only one isomer of the possible two isomers can be obtained by these reactions and nowadays selective synthesis of both isomers is required. The present article reviews the current advancement for selective diastereoface differentiating reactions to give both isomers especially relating to nucleophilic addition reactions to carbonyl compounds with an asymmetric center. Fundamental significance is to utilize metal reagents possessing various coordinating abilities.View full abstractDownload PDF (1516K) -
Junji INANAGA1989 Volume 47 Issue 3 Pages 200-211
Published: March 01, 1989
Released on J-STAGE: January 22, 2010
JOURNAL FREE ACCESSSince samarium diiodide (SmI2) was introduced into organic synthesis as a synthetic means by Kagan et al., quite unique and useful properties of the reagent has been emerging. In this article will be disclosed our recent efforts in this area. (1) Transition metal-catalyzed C-H, C-C, and C-Sn bond formation via polarity inversion of allylic and propargylic acetates. (2) Transition metal-catalyzed reduction of triple bonds. (3) Facile reduction of organic halides, epoxides, α, β-epoxy esters, α -oxygenated esters, organoheteroatom oxides, and conjugated acid derivatives with the highly efficient reduction system, SmI2-THE-HMPA. (4) A variety of C-C bond-forming reactions : The use of β-, γ-, and δ-bromoesters as home-, bishomo-, and trishomoenolate equivalents, respectively, in Barbier-type reaction ; iodomethylation of carbonyl compounds at room temperature ; construction of benzofuran and indole frameworks via aryl radical cyclization ; a novel masked-formylation of carbonyl compounds with 1, 3-dioxolane ; preparation of medium- and large-ring lactones by intramolecular Reformatsky-type reaction ; reductive self-dimerization of a-bromo esters and conjugated acid derivatives. (5) Intermolecular addition of ketyls to olefins and acetylenes. A high degree of acyclic stereoselection was realized in an intermolecular radical reaction for the first time by utilizing the distinct property of SmI2.View full abstractDownload PDF (1294K) -
Kimiko HASHIMOTO, Haruhisa SHIRAHAMA1989 Volume 47 Issue 3 Pages 212-223
Published: March 01, 1989
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSRecent syntheses of kainoids were reviewed with 96 references. In the syntheses, formation of the proline nucleus and stereochemical arrangement of the substituents around the proline ring were the key steps, in which ene-reactions, homo- and hetero-Diels-Alder reactions, radical ring closures, Claisen rearrangement and 1, 3-dipolar cyclo-additions were mainly employed. A new method for a pyridine synthesis was also developed for acromelic acids. The synthetic schemes were classified into the following 5 groups according to the position of C-C bond formation in the key steps. 1) C3-C4 bond formation, 2) C2-C3 and C4-C5 bond formation, 3) side chain introduction to proline moiety, 4) conversion of kainic acid to other kainoids and 5) some other synthetic approaches and syntheses of derivatives.View full abstractDownload PDF (1331K) -
Hiroto NAGAOKA1989 Volume 47 Issue 3 Pages 224-232
Published: March 01, 1989
Released on J-STAGE: January 22, 2010
JOURNAL FREE ACCESSThe first total synthesis of (±) -sanadaol, structurally unique marine diterpene isolated from brown algae Pachydictyon coriaceum and Dictyota crenulata, is described. The key step of this fully stereocontrolled synthesis involves the fragmentation reaction of tricyclic compound 21 forming bicyclic compound 22 having suitably functionalised framework of sanadaol. Further, both (-) - and (+) -sanadaol were synthesized stereoselectively from D-mannitol via chiral bicyclo [2.2.2] octane derivative 47. This accomplishment determined the absolute configuration of sanadaol and that of dictyodial as shown in (+) -1 and 59, respectively.View full abstractDownload PDF (1079K) -
Makoto ONAKA, Yusuke IZUMI1989 Volume 47 Issue 3 Pages 233-245
Published: March 01, 1989
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSVarious cation-exchanged zeolites have been applied to organic reactions in a liquid-phase as an acid-base bifunctional catalyst (promoter), an efficient support for inorganic nucleophiles, and an inorganic, rigid ligand for transition metals.
Alkali cation-exchanged Y-type zeolites promote nucleophilic substitution reactions such as O-benzylation of alcohols with benzyl chloride, selective N-monoalkylation of anilines with alkylating agents, and ring-openings of epoxides. In those reactions acid sites and base sites on the zeolite surface prove to activate the reactants synergistically by our correlating the chemical properties of the zeolite with the chemical reactivities.
Inorganic nucleophiles supported on calcium ion-exchanged zeolite induce the highly regioselective ringopenings of 2, 3-epoxy alcohols affected by the specific interaction of the epoxy alcohols with calcium ions in the zeolite.
Cupric ions surrounded by the rigid framework of zeolite catalyze the decomposition of aryldiazomethanes to give cis-1, 2-diarylethylenes predominantly. In homogeneous, small pores of zeolites, organic reactions are found to proceed in a highly restricted way.View full abstractDownload PDF (1409K) -
Charge Control Agents and ColorformerYutaka SATO, Isao NIIMURA, Masahiko YAMAGUCHI1989 Volume 47 Issue 3 Pages 246-257
Published: March 01, 1989
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSA review on charge control agent which is one of the additives used in the toner of electrophotographic copier or printer is described. Some informations are obtained through the synthesis of metal complex azo dyes for charge control agent. High ability charge control agent for negative charge toner is doveloped manufactured commercially.
We introduce Crystal Violet Lactone (CVL) and 2-Anilno-3-methyl-6-diethylamino fluoran (N-102) as representative examples of colorformer which is used for pressure sensitive copying paper and thermosensitive recording paper. Synthetic method of these compoumds are reviewed with authors several technical comments.View full abstractDownload PDF (1143K) -
Enhancement of Reactivity of Potassium Fluoride on the Halogen-Exchange Fluorination ReactionsYoshikazu KIMURA1989 Volume 47 Issue 3 Pages 258-264
Published: March 01, 1989
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSThe title reactions have been widely utilized in a laboratory and an industrial use for the preparation of aromatic fluoride derivatives. The advantage is a simple and convenient procedure which is avoidable the use of dangerous hydrogen fluoride. However, owing to poor solubilities of metal fluorides (mainly potassium fluoride) in organic solvents, the halogen-exchange fluorination with these reagents often requires elevated temperatures in polar solvents, which are accompanied by the decomposition of the starting substrates and/or products. In this article, numerous devotions will be reviewed to enhance the activity of potassium fluoride from the literature published since 198O.View full abstractDownload PDF (776K) -
Kouji KUMADA1989 Volume 47 Issue 3 Pages 265-266
Published: March 01, 1989
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSDownload PDF (182K) -
[in Japanese], [in Japanese]1989 Volume 47 Issue 3 Pages 267
Published: March 01, 1989
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSDownload PDF (155K)
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