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翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Ring-closing metathesis ： ウィキペディア英語版 Ring-closing metathesis Ring-closing metathesis, or RCM, is a widely used variation of olefin metathesis in organic chemistry for the synthesis of various unsaturated rings via the intramolecular metathesis of two terminal alkenes, which forms the cycloalkene as the ''E-'' or ''Z-'' isomers and volatile ethylene.〔Carey, F. A.; Sunburg, R. J. Reactions Involving Transition Metals. ''Advanced Organic Chemistry: Reaction and Synthesis'', 5th Ed.; Part B; Springer: New York, 2010, pp. 761-767.〕〔Monfette, S.; Fogg, D. E. (2009). "Equilibrium Ring-Closing Metathesis". ''Chem. Rev.'' 109 (8): 3783-3816. .〕 The most commonly synthesized ring sizes are between 5-7 atoms;〔Deiters, A.; Martin, S. F. (2004). “Synthesis of Oxygen- and Nitrogen-Containing Heterocycles by Ring-Closing Metathesis”. ''Chem. Rev.'' 104 (5): 2199-2238. .〕 however, reported syntheses include 45- up to 90- membered macroheterocycles.〔Cain, M. F.; Forrest, W. P.; Peryshkov, R. V.; Schrock, R. R. Muller, P. (2013). “Synthesis of a TREN in Which the Aryl Substituents are Part of a 45 Atom Macrocycle”. ''J. Am. Chem. Soc.'' 135 (41): 15338-15341. .〕〔Dasgupta, S.; Wu, J. (2011). “Template-directed synthesis of kinetically and thermodynamically stable molecular necklace using ring closing metathesis”. ''Org. Biomol. Chem.'' 9: 3504-3515. 〕〔Song, K. H.; Kang, S. O.; Ko, (2007). “Template Synthesis of a Huge Macrocycle by Olefin Metathesis Using Easily Accessible () Templates”. ''Chem. Eur. J.'' 13 (18): 5129–5134. .〕 These reactions are metal-catalyzed and proceed through a metallacyclobutane intermediate.〔Schmalz, H.-G. (1995). “Catalytic Ring-Closing Metathesis : A New, Powerful Technique for Carbon- Carbon Coupling in Organic Synthesis”. ''Angew. Chem. Int. Ed. Engl.'' 34 (17): 1833-1836. .〕 It was first published by Dider Villemin in 1980 describing the synthesis of an Exaltolide precursor,〔Villemin, D. (1980). “Synthese de Macrolides par Metathese”. ''Tetrahedron Lett.'' 21 (18): 1715-1718. .〕 and later become popularized by Robert H. Grubbs and Richard R. Schrock, who shared the Nobel Prize in Chemistry, along with Yves Chauvin, in 2005 for their combined work in olefin metathesis.〔Grubbs, R. H. (2006). “Olefin-Metathesis Catalysts for the Preparation of Molecules and Materials (Nobel Lecture)”. ''Angew. Chem., Int. Ed.'' 45 (23): 3760–3765. .〕〔Schrock, R. R. (2006). “Multiple Metal–Carbon Bonds for Catalytic Metathesis Reactions (Nobel Lecture)”. ''Angew. Chem., Int. Ed.'' 45 (23), 3748-3759. .〕 RCM is a favorite among organic chemists due to its synthetic utility in the formation of rings, which were previously difficult to access efficiently, and broad substrate scope.〔Trnka, T. M.; Grubbs, R. H. (2001). “The Development of L2X2Ru=CHR Olefin Metathesis Catalysts: An Organometallic Success Story”. ''Acc. Chem. Res.'' 34 (1):18-29. .〕 Since the only major by-product is ethylene, these reactions may also be considered atom economic, an increasingly important concern in the development of green chemistry.〔 There are several reviews published on ring-closing metathesis.〔〔〔Furstner, A. (2000). “Olefin Metathesis and Beyond”. ''Angew. Chem., Int. Ed.'' 39 (17): 3012-3043. .〕〔Gradillas, A.; Perez-Castells, J. (2006). “Macrocyclization by Ring-Closing Metathesis in the Total Synthesis of Natural Products: Reaction Conditions and Limitations”. ''Angew. Chem., Int. Ed.'' 45: 6086-6101. .〕 ==History== The first example of ring-closing metathesis was reported by Dider Villemin in 1980 when he synthesized an Exaltolide precursor using a WCl6/Me4Sn catalyzed metathesis cylcization in 60-65% yield depending on ring size (A).〔 In the following months, Jiro Tsuji reported a similar metathesis reaction describing the preparation of a macrolide catalyzed by WCl6 and dimethyltitanocene (Cp2TiMe2) in a modest 17.9% yield (B).〔Tsuji, J.; Hashiguchi, S. (1980). “Application of Olefin Metathesis to Organic Synthesis. Syntheses of Civetone and Macrolides”. ''Tetrahedron Lett.'' 21 (31): 2955-2958. .〕 Tsuji describes the olefin metathesis reaction as “…potentially useful in organic synthesis” and addresses the need for the development of a more versatile catalyst to tolerate various functional groups. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Ring-closing metathesis」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.