Pd-Catalyzed Perfluoroalkylative Aryloxycarbonylation of Alkynes with Formates as CO Surrogates
Pd-Catalyzed Perfluoroalkylative Aryloxycarbonylation of Alkynes with Formates as CO Surrogates
复制标题
DOI：
10.1021/acscatal.1c00671
复制
发表时间：
2021-05-19
期刊：
影响因子：
12.9
通讯作者：
Chaladaj, Wojciech
中科院分区：
文献类型：
--
作者：
Gatlik, Beata;Chaladaj, Wojciech
CO的高毒性、易燃性和无臭性导致在实验室规模的实验中处理有问题。用CO替代物代替CO气瓶是特别有吸引力的，特别是在多组分反应产生有价值的氟化产物的情况下。我们报告了一个Pd催化的三组分协议，用于从乙炔和全氟烷基碘直接合成全氟烷基取代的α，β-不饱和酯，甲酸酯作为方便的CO来源。串联反应在温和的条件下进行，对E-异构体具有优异的区域和立体选择性（>95：5，E：Z）。详细的机理研究表明，该过程通过关闭循环，碱诱导的甲酸盐分解为CO和酚盐，其在Pd中心上重新组装成芳氧基羰基部分，其最终安装在烯烃支架上。为了完成反应的机理图，实验研究得到了DFT计算的支持。
The highly toxic, inflammable, and odorless nature of CO causes problematic handling on laboratory-scale experiments. Replacement of CO cylinders by CO surrogates is particularly attractive, especially in the case of multicomponent reactions leading to valuable fluorinated products. We report a Pd-catalyzed three-component protocol for the direct synthesis of perfluoroalkyl-substituted alpha,beta-unsaturated esters from acetylenes and perfluoroalkyl iodides, applying formates as convenient CO sources. The tandem reaction proceeds under mild conditions with excellent regio- and stereoselectivities toward the E-isomer (>95:5, E:Z). Detailed mechanistic investigations revealed that the process proceeds through an off-cycle, base-induced decomposition of formate to CO and phenoxide, which are reassembled on the Pd-center into an aryloxycarbonyl moiety, which is ultimately installed on the alkene scaffold. To complete the mechanistic picture of the reaction, the experimental study was supported by DFT calculations.