A General Palladium-Catalyzed Suzuki-Miyaura Coupling of Aryl Mesylates
A General Palladium-Catalyzed Suzuki-Miyaura Coupling of Aryl Mesylates
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DOI：
10.1002/anie.200803193
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发表时间：
2008-01-01
影响因子：
16.6
通讯作者：
Kwong, Fuk Yee
中科院分区：
文献类型：
--
作者：
So, Chau Ming;Lau, Chak Po;Kwong, Fuk Yee
钯催化的交叉偶联反应已经成为有机合成中一种极其通用的工具，用于通过形成碳-碳或碳-杂原子键连接亲电片段和有机金属片段。[1]特别地，Suzuki-Miyaura反应，采用有机硼亲核试剂，代表了用于构建C（sp2）→ C（sp2）键的有效方法，并且在药物、材料和农业化学中具有许多应用。[2]除了芳基碘化物、溴化物和最近的氯化物外，[3]芳基和乙烯基磺酸酯，如三氟甲磺酸酯、九氟丁磺酸酯和甲苯磺酸酯，是钯催化的交叉偶联反应的有用的替代亲电试剂[4，5]，并且容易分别从酚和酮获得。最近，已经研究了过多的配体来解决困难的钯催化的芳基甲苯磺酸酯偶联。[6，7] Buchwald的X-Phos在芳基芳烃磺酸盐的Suzuki-Miyaura、Buchwald-Hartwig和Sonogashira反应中显示出优异的反应性（图1）。[6a，f，h] Ackermann的PinP（O）H能够实现甲苯磺酸芳基酯的高效Kumada交叉偶联（图1）。[6e]有趣的是，注意到Josiphine型配体（图1）。[8]对甲苯磺酸芳基酯的Kumada偶联有效，[6d]但在甲苯磺酸芳基酯的Suzuki型偶联中较差。[6a]配体的结构似乎是成功实现特定催化反应的关键。一般来说，在偶联反应中，甲磺酸芳基酯比相应的芳烃磺酸芳基酯（如苯磺酸酯或对甲苯磺酸酯）惰性大得多。[9]尽管已经报道了镍催化的甲磺酸酯偶联，但是能够偶联甲磺酸芳基酯的通用钯系统的先例仍然很少。[10]迄今为止，只有两个出版物报道钯催化的甲磺酸酯偶联。Buchwald及其同事报道了在乙酸钯和双齿膦配体Cy 2 P（CH 2）3 PCy 2·HBF 4的存在下C3 CN键的形成（羰基化），[6 j]而我们的小组报道了在Pd/L2的存在下C3 CN键的形成（胺化）（参见方案1）。[11]芳基
Palladium-catalyzed cross-coupling reactions have become an extremely versatile tool in organic synthesis for the connection of electrophilic and organometallic fragments by the formation of either carbon–carbon or carbon–heteroatom bonds.[1] In particular, the Suzuki–Miyaura reaction, employing organoboron nucleophiles, represents an effective method for the construction of C (sp2) ÀC (sp2) linkages, and has numerous applications in pharmaceutical, material, and agricultural chemistry.[2] In addition to aryl iodides, bromides, and, more recently, chlorides,[3] aryl and vinyl sulfonates, such as triflates, nonaflates, and tosylates, are useful alternative electrophiles for palladium-catalyzed cross-coupling reactions [4, 5] and are readily available from phenols and ketones, respectively. Recently, a plethora of ligands have been investigated to tackle difficult palladium-catalyzed aryl tosylate couplings.[6, 7] Buchwald s X-Phos displays excellent reactivity in Suzuki–Miyaura, Buchwald–Hartwig, and Sonogashira reactions of aryl arenesulfonates (Figure1).[6a, f, h] Ackermann s PinP (O) H enables the highly efficient Kumada cross-coupling of aryl tosylates (Figure 1).[6e] It is interesting to note that Josiphos-type ligands (Figure 1).[8] are effective for Kumada coupling of aryl tosylates,[6d] yet are inferior in Suzuki-type coupling of aryl tosylates.[6a] Ligand structure seems to be crucial in successfully achieving specific catalytic reactions.In general, aryl mesylates are considerably more inert than the corresponding aryl arenesulfonates (eg benzenesulfonate or p-toluenesulfonate) in coupling reactions.[9] Although nickel-catalyzed mesylate couplings have been reported, precedents for a general palladium system capable of coupling aryl mesylates remain scarce.[10] To date, only two publications report palladium-catalyzed mesylate couplings. Buchwald and co-workers reported CÀC bond formation (carbonylation) in the presence of palladium acetate and the bidentate phosphane ligand Cy2P (CH2) 3PCy2· HBF4,[6j] whereas our group reported CÀN bond formation (amination) in the presence of Pd/L2 (see Scheme 1).[11] Aryl