C-H Alkenylation of Azoles with Enols and Esters by Nickel Catalysis
C-H Alkenylation of Azoles with Enols and Esters by Nickel Catalysis
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DOI：
10.1002/anie.201304492
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发表时间：
2013-09-16
影响因子：
16.6
通讯作者：
Itami, Kenichiro
中科院分区：
文献类型：
--
作者：
Meng, Lingkui;Kamada, Yuko;Itami, Kenichiro
过渡金属催化的烯基化反应是制备烯基取代芳烃最可靠的方法之一，Mizoroki-Heck反应就是一个例子最近，直接CÀH烯基化[2]作为构建烯基化芳烃，特别是烯基化杂芳烃的新兴工具受到越来越多的关注，因为它们是生物活性天然产物、药物和有机材料中的主要基序（Scheme 1a）CÀH烯化反应的代表性反应类型包括（方案1b）： 1)钯和铜催化下杂芳烃与卤化烯的烯化反应（X=卤素，包括三氟酸盐）CÀH/CÀX; 2)钯和铑催化下杂芳烃与简单烯烃的烯化反应（氧化Mizoroki-Heck反应）CÀH/CÀH还存在其他CÀH联轴器，它们不在上述范畴的范围内同时，我们的团队开发了一些独特的CÀH由过渡金属配合物催化的杂芳烃芳基化反应。[8-10]例如，我们最近首次发现了镍催化的杂环芳烃与苯酚衍生物的CÀH/CÀO偶联[10a]，以及杂环芳烃与芳基酯之间的脱羰CÀH偶联。[10b]这些催化过程在其他CÀH芳基化方法中是独特的，不仅因为它们允许在CÀH芳基化（苯酚衍生物和芳烃羧酸酯）中加入非常规芳基亲电试剂，而且还因为这些反应是由一个支持配体1,2 -二（双环己基膦）乙烷（型）在镍(0)催化剂上唯一促进的（其他密切相关的配体在这些催化剂中显示极低或没有促进作用）。基于这些令人愉快的发现，我们提出了一个问题：用烯醇衍生物[方案1b， 4)]和α， β-不饱和酯[方案1b， 5)]作为烯化剂，是否可能在Ni/型催化剂下实现史无前例的CÀH杂环烃烯化反应。杂芳烃的CÀH/CÀO烯化反应是罕见的，而脱羰的CÀH烯化反应迄今为止是未知的。在此，我们报告CÀH
Transition metal catalyzed alkenylation is one of the most reliable methods for making alkenyl-substituted arenes as exemplified by the Mizoroki–Heck reaction.[1] Recently, direct CÀH alkenylation [2] has received growing interest as an emerging tool for constructing alkenylated arenes and particularly alkenylated heteroarenes, since they are predominant motifs in biologically active natural products, pharmaceuticals and organic materials (Scheme 1a).[3] Representative reaction types of CÀH alkenylation include (Scheme 1 b): 1) CÀH/CÀX alkenylation (X= halogens including triflates) of heteroarenes with alkenyl halides by using palladium and copper catalysts,[4] 2) CÀH/CÀH alkenylation (oxidative Mizoroki–Heck reaction) of heteroarenes with simple alkenes by using palladium and rhodium catalysts,[5] and 3) CÀH addition of heteroarenes to alkynes by transitionmetal catalysts.[6] There also exist other CÀH couplings which are outside the realm of the above-mentioned category.[7] Meanwhile, our group has developed a number of unique CÀH arylation reactions of heteroarenes catalyzed by transition-metal complexes.[8–10] For example, we recently discovered the first nickel-catalyzed CÀH/CÀO coupling of heteroarenes and phenol derivatives [10a] as well as a decarbonylative CÀH coupling between heteroarenes and aryl esters.[10b] These catalytic processes are unique among other CÀH arylation methods not only because they allow incorporation of unconventional aryl electrophiles in CÀH arylation (phenol derivatives and arenecarboxylates), but also because these reactions are uniquely promoted by an enabling supporting ligand, 1, 2-bis (dicyclohexylphosphino) ethane (dcype), on a nickel (0) catalyst (other closely related ligands display extremely low or no promoting effect in these catalyses). Based on these auspicious discoveries, we questioned whether unprecedented CÀH alkenylations of heteroarenes would become possible with a Ni/dcype catalyst by using enol derivatives [Scheme 1 b, 4)] and α, β-unsaturated esters [Scheme 1b, 5)] as alkenylation agents. The CÀH/CÀO alkenylation of heteroarenes is rare,[11] and the decarbonylative CÀH alkenylation is thus far unknown. Herein, we report the CÀH