Manganese(III) Acetate: A Versatile Reagent in Organic Chemistry
Manganese(III) Acetate: A Versatile Reagent in Organic Chemistry
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DOI：
10.2174/157017907781369289
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发表时间：
2007-07
影响因子：
1.8
通讯作者：
A. Demir;M. Emrullahoğlu
中科院分区：
文献类型：
--
作者：
A. Demir;M. Emrullahoğlu
近二十年来，自由基反应因其强大的选择性、特异性和温和的反应能力，在有机合成中已成为一种越来越重要和有吸引力的工具。近二十年来，Mn(OAc)3介导的氧化自由基反应得到了广泛的研究。许多区域选择性、化学选择性和立体选择性合成方法在分子间和分子内反应中都得到了发展，并详细介绍了自19世纪末以来Mn(OAc)3介导的氧化自由基反应的进展。关于Mn(OAc)3介导的碳-碳键和碳-氧键生成反应的新合成方法的新文献尚未得到广泛的综述。本文综述了锰（OAc）3在氧化自由基反应中的研究进展。Mn(OAc)3介导的共轭体系（如烯烃、炔烃、1,3-烷二烯、1,3-烷二烯、1-烯烃-3-炔）与-二羰基化合物的反应，Mn(OAc)3介导的烷基化反应，如醛或酮对烯烃的氧化加成，Mn(OAc)3介导的烯烃与活性亚甲基化合物在氧存在下的自由基环化反应，以提供环过氧化物；通过Mn(OAc)3介导羧酸对烯烃的氧化加成合成内酯，Mn(OAc)3介导-（甲基硫）乙酰酰胺、烯酰胺和-酮羧酰胺的环化生成环产物。Mn(OAc)3氧化自由基环化烯丙基二羰基化合物，例如，环化烯丙基酮酯得到相应的内酯。研究了烯烃与叠氮化钠在乙酸存在下的反应，得到了1.2-二叠氮化钠。烯酮在Mn(OAc)3氧化作用下选择性氧化生成- '-乙氧基烯酮。一般来说，Mn(OAc)3氧化的特点是具有较高的'-区域选择性和化学产率，以及较温和的反应条件，从而可以耐受许多敏感官能团。Mn(OAc)3与其他羧酸或锰（II）羧酸盐结合使用，将该方法扩展到制备各种'-酰基氧基酮，否则在一步程序中无法获得。1. 金属促进的自由基反应在有机合成中有广泛的应用，其中一个众所周知的应用例子是锰（III）醋酸酯介导的反应。这一领域令人兴奋的发展开始显示出其真正的潜力，这一方法在复杂分子合成过程中策略级键形成的应用证明了这一点。二水合醋酸锰（III）（简称Mn(OAc)3）介导的自由基反应已成为合成新键和断键的重要方法。鉴于其在有机合成中的重要性，本文综述了Mn(OAc)3促进自由基反应在碳-碳、碳-杂原子键形成中的应用，并涵盖了1993年以来的文献。
Free radical reactions have become increasingly important, as well as a very attractive tool, in organic synthesis within the last two decades, due to their powerful, selective, specific, and mild reaction abilities. Mn(OAc)3 mediated oxidative free radical reactions have been extensively developed in the last twenty years. Numerous regio-, chemo-, and stereoselective synthetic methods have been developed in both inter- and intramolecular reactions, and have detailed the progress of Mn(OAc)3 mediated oxidative free radical reactions since the end of the 19 th century. The new literature about the new synthetic methods on Mn(OAc)3 mediated carbon-carbon bond formation and carbon-oxygen bond formation reactions has not been extensively reviewed. The present paper summarizes the recent developments in oxidative free radical reactions mediated by Mn(OAc)3. Mn(OAc)3 mediated reactions of conjugated systems (e.g., alkenes, alkynes, 1,3-alkadienes, l,3-alkadiynes, 1-alken-3-ynes) with � -dicarbonyl compounds, Mn(OAc)3 mediated alkylation, such as the oxidative addition of an aldehyde or ketone to alkenes, Mn(OAc)3 mediated free-radical cyclization of alkenes with active methylene compounds in the presence of oxygen to afford the cyclic peroxides; lactone synthesis by the Mn(OAc)3 mediated oxidative addition of carboxylic acids to alkenes, Mn(OAc)3 mediated cyclization of � - (methylthio)acetamides, enamides, and � -keto carboxamides to afford cyclic products. Mn(OAc)3 oxidative free-radical cyclizations of allylic � -dicarbonyl compounds, for example, the cyclization of allylic � -ketoesters to afford the corresponding � -lactone. The reaction of alkenes with sodium azide in the presence of acetic acid was investigated to afford 1.2-diazides. The selective oxidation of enones led to � '-acetoxy-enones by Mn(OAc)3 oxidation. In general, Mn(OAc)3 oxi- dations are characterized by higher '-regioselectivity and chemical yields, and milder reaction conditions, in turn tolerating many sensitive functional groups. The use of Mn(OAc)3 in combination with other carboxylic acids or manganese(II) carboxylates ex- tends this methodology to the preparation of a variety of '-acyloxyenones that are otherwise inaccessible in a one-step procedure. 1. MANGANESE(III) ACETATE: INTRODUCTION AND GENERAL DESCRIPTION Metal-promoted radical reactions have found widespread use in organic synthesis, in which one of the well-known examples of this application is the manganese(III) acetate mediated reactions. The exciting development in this area is beginning to show its true po- tential, as evidenced from the application of this methodology in strategy-level bond formation during the synthesis of complex molecules. Manganese(III) acetate dihydrate (abbreviated herein as Mn(OAc)3) mediated free radical reactions have emerged as impor- tant synthetic methods for a new bond formation and bond break- ing. In view of its importance in organic synthesis, this present review highlights the application of Mn(OAc)3 promoted free- radical reactions in carbon-carbon, carbon-heteroatom bond forma- tion, and covers the literature since 1993.