Palladium(II)-Catalyzed Directed anti-Hydrochlorination of Unactivated Alkynes with HCl
Palladium(II)-Catalyzed Directed anti-Hydrochlorination of Unactivated Alkynes with HCl
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DOI：
10.1021/jacs.7b00892
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发表时间：
2017-04-12
影响因子：
15
通讯作者：
Engle, Keary M.
中科院分区：
文献类型：
--
作者：
Derosa, Joseph;Cantu, Annabelle L.;Engle, Keary M.
报道了一种非活化炔的区域选择性抗氢氯化反应。该反应利用原位生成的HCl作为Cl-和H+的来源，由醋酸钯（II）催化，负载量低至25 ppm。可移动的吡啶酰胺和8-氨基喹啉双齿定向基团用于控制氯化步骤的区域选择性，并稳定产生的烯基钯（II）中间体，用于随后的原脱层。这种方法以优异的收率和高的区域选择性获得了一系列取代的烯酰氯。该转化产物通过Stille偶联成功衍生为多种三取代烯烃产物。进行了反应过程动力学分析，揭示了该催化过程的可能机理。
A regioselective anti-hydrochlorination of unactivated alkynes is reported. The reaction utilizes in situ generated HCl as the source of both the Cl- and H+ and is catalyzed by palladium(II) acetate, with loadings as low as 25 ppm. Removable picolinamide and 8-aminoquinoline bidentate directing groups are used to control the regioselectivity of the chloropalladation step and stabilize the resulting alkenylpalladium(II) intermediate for subsequent protodepalladation. This method provides access to a broad array of substituted alkenyl chlorides in excellent yields and with high regioselectivity. The products from this transformation were successfully derivatized via Stille coupling to a variety of trisubstituted alkene products. Reaction progress kinetic analysis was performed, shedding light on a possible mechanism for this catalytic process.