Ruthenium-Catalyzed Isoquinolone Synthesis through C-H Activation Using an Oxidizing Directing Group
Ruthenium-Catalyzed Isoquinolone Synthesis through C-H Activation Using an Oxidizing Directing Group
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使用氧化导向基团通过 C-H 活化钌催化异喹诺酮合成
DOI：
10.1002/chem.201102445
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发表时间：
2011-11-04
影响因子：
4.3
通讯作者：
Wang, Baiquan
中科院分区：
文献类型：
--
作者：
Li, Bin;Feng, Huiliang;Wang, Baiquan
近年来，过渡金属催化的氧化CÀH活化过程引起了人们的极大兴趣，因为这种方法消除了激活底物的先决步骤因此，通常需要使用外部氧化剂来再生催化剂。近两年来，在这一领域出现了一种新的策略，即使用氧化导向基团同时充当导向基团和（内）氧化剂，从而消除了对外部助氧化剂的需要，在温和的反应条件下提高了反应活性和选择性，并减少了废物的产生这种高效的方法是由Cui和Wu、[3]Hartwig、[4]Yu、[5]Guimond和Fagnou、[6]和Glorius等课课组在钯和铑催化的CÀH键转化反应中独立开发的。在最近的工作中，Miura和Satoh， Fagnou，[9]和Jones分别报道了铑催化剂是通过CÀH键活化炔烃氧化环化反应的有效催化剂因此，铑催化合成异喹诺酮[12]的方法在过去的四年中得到了发展。[6,13]相比之下，类似的钌催化过程较少被探索。Ackermann的研究小组在最近的一份开创性的、优雅的报告中，首次证明了钌催化的炔与苯酰胺的氧化环化反应[Eq.(1)]然而，高的反应温度（1108C），大量过量的炔（2.0当量）和外部氧化剂[CuACHTUNGTRENNUNG (OAc) 2·H2O， 2.0当量]是新转化的必要条件。
Transition-metal-catalyzed oxidative CÀH activation processes have received significant interest in recent years, because such approaches eliminate the need for prior steps to activate the substrate.[1] Consequently, the use of an external oxidant is generally demanded to regenerate the catalyst. In the last two years, a new strategy—the use of an oxidizing directing group that acts as both directing group and (internal) oxidant—has emerged in this field, which obviates the need for an external co-oxidant, increases the reactivity and selectivity under mild reaction conditions, and reduces the amount of waste formed.[2] This efficient method has been independently developed in palladium-and rhodium-catalyzed CÀH bond transformation reactions by the research groups of Cui and Wu,[3] Hartwig,[4] Yu,[5] Guimond and Fagnou,[6] and Glorius.[7]In recent work, Miura and Satoh,[8] Fagnou,[9] and Jones [10] independently reported that rhodium catalysts were competent catalysts for oxidative annulation reactions of alkynes through CÀH bond activation.[11] As a result, methods for rhodium-catalyzed isoquinolone [12] syntheses have been developed during the last four years.[6, 13] In contrast, the analogous ruthenium-catalyzed processes [14] were less explored. In a very recent pioneering and elegant report, the research group of Ackermann demonstrated the first ruthenium-catalyzed oxidative annulation reaction of alkynes with benzamide [Eq.(1)].[15] Nevertheless, a high reaction temperature (1108C), large excess of the alkyne (2.0 equiv) and an external oxidant [CuACHTUNGTRENNUNG (OAc) 2· H2O, 2.0 equiv] were necessary for this new transformation.