Nickel-Catalyzed Direct C-H Arylation and Alkenylation of Heteroarenes with Organosilicon Reagents
Nickel-Catalyzed Direct C-H Arylation and Alkenylation of Heteroarenes with Organosilicon Reagents
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DOI：
10.1002/anie.200906996
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发表时间：
2010-01-01
影响因子：
16.6
通讯作者：
Miura, Masahiro
中科院分区：
文献类型：
--
作者：
Hachiya, Hitoshi;Hirano, Koji;Miura, Masahiro
有机硅化合物是现代有机化学中有用且普遍存在的合成试剂。在涉及它们的多功能转化中，过渡金属催化的有机卤化物或拟卤化物的交叉偶联反应，即桧山交叉偶联，被列为有机合成中最强大和最可靠的CÀC键形成反应之一。 [1] Nakao、Hiyama 及其同事[2] 以及丹麦等人[3] 最近的努力引入新型稳定且易于操作的硅基偶联试剂以增强反应的通用性。相比之下，Fu和同事[4]以及Wu和同事[5]开发的新型催化剂体系将有机亲电子试剂的范围分别扩大到未活化的烷基卤化物和芳烃磺酸盐。此外，Hiyama偶联具有显着的优点，包括与有机硅化合物以及Suzuki-Miyaura偶联中的有机硼试剂相关的易处理性、低毒性和环境友好性。同时，通过直接C-H官能化形成金属介导的C-C键[6]作为传统交叉偶联方法的潜在更有效和补充过程而受到广泛关注。尽管多种芳烃和杂芳烃与芳基硼酸衍生物的直接芳基化已经实现，[7, 8]相应的与有机硅烷的直接偶联仍然难以实现。据我们所知，迄今为止只报道了两个成功的例子。 [9]此外，这些过程依赖于钯催化，并且底物仅限于含有乙酰胺部分的底物，因为螯合辅助的环钯化步骤在催化反应中至关重要。在此，我们报告了一种新型镍基催化剂体系，用于各种杂芳烃与有机硅烷的直接 CÀH 芳基化和烯基化。 [10]作为初始实验，在 10 mol% NiBr2·二甘醇二甲醚、10 mol% 1, 10-菲咯啉 (phen) 和 CsF 的存在下，在 3.0 mL N, N-二甲基乙酰胺 (DMAc) 中，在 1508°C 空气下（O2 作为溶剂），用三甲氧基苯基硅烷（2a，1.0 mmol）处理苯并恶唑（1a，0.50 mmol）氧化剂）
Organosilicon compounds are useful and ubiquitous synthetic reagents in modern organic chemistry. Among the versatile transformations involving them, transition metal catalyzed cross-coupling reactions of organic halides or pseudohalides, that is Hiyama cross-coupling, ranks as one of the most powerful and reliable CÀC bond-forming reactions in organic synthesis.[1] Recent efforts by Nakao, Hiyama, and co-workers,[2] and Denmark et al.[3] introduce new types of stable and easy-to-handle silicon-based coupling reagents to enhance the generality of the reaction. In contrast, the development of new catalyst systems by Fu and co-workers [4] and Wu and coworkers [5] has expanded the scope of organic electrophiles into unactivated alkyl halides and arenesulfonates, respectively. In addition, the Hiyama coupling has significant benefits involving tractability, low toxicity, and environmentally benignity associated with organosilicon compounds, as well as organoboron reagents in the Suzuki–Miyaura coupling.Meanwhile, metal-mediated CÀC bond formation through direct CÀH functionalization [6] has received much attention as a potentially more efficient and complementary process to the conventional cross-coupling methodology. Although the direct arylation of a variety of arenes and heteroarenes with arylboronic acids derivatives has been achieved,[7, 8] the corresponding direct coupling with organosilanes still remains elusive. To the best of our knowledge, only two successful examples have been reported to date.[9] Moreover, these processes rely on the palladium catalysis, and substrates are limited to those containing an acetamide moiety as the chelation-assisted cyclopalladation step is crucial in the catalytic reaction. Herein we report a new nickel-based catalyst system for the direct CÀH arylation and alkenylation of various heteroarenes with organosilanes.[10] As an initial experiment, treatment of benzoxazole (1a, 0.50 mmol) with trimethoxyphenylsilane (2a, 1.0 mmol) in the presence of 10 mol% of NiBr2· diglyme, 10 mol% of 1, 10-phenanthroline (phen), and CsF in 3.0 mL of N, N-dimethylacetamide (DMAc) at 1508C under air (O2 as an oxidant)