Chen Yixin, He Yuchen, Gao Yong, Xue Jiakun, Qu Wei, Xuan Jun, Mo Yiming
College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027 Zhejiang, China.
Engineering Research Center of Functional Materials Intelligent Manufacturing of Zhejiang Province, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 311215, China.
Science. 2024 May 10;384(6696):670-676. doi: 10.1126/science.adm8902. Epub 2024 May 9.
Electrochemistry offers a sustainable synthesis route to value-added fine chemicals but is often constrained by competing electron transfer between the electrode and redox-sensitive functionalities distinct from the target site. Here, we describe an ion-shielding heterogeneous photoelectrocatalysis strategy to impose mass-transfer limitations that invert the thermodynamically determined order of electron transfer. This strategy is showcased to enable decarboxylative trifluoromethylation of sensitive (hetero)arenes by using trifluoroacetate, an inexpensive yet relatively inert trifluoromethyl group (CF) source. An ion-shielding layer, formed by trifluoroacetate anions electrostatically adsorbed on a positive molybdenum-doped tungsten trioxide (WO) photoanode, prevents undesired electron transfer between substrates and photogenerated holes. The practicality of the developed method was demonstrated with robust photoanode stability (approximately 380 hours), a good substrate scope, and scaling capability to achieve 100-gram synthesis by using photoelectrochemical flow cells.
电化学为增值精细化学品提供了一条可持续的合成路线，但往往受到电极与目标位点不同的氧化还原敏感官能团之间竞争性电子转移的限制。在此，我们描述了一种离子屏蔽异质光催化策略，以施加传质限制，从而颠倒热力学确定的电子转移顺序。该策略通过使用三氟乙酸盐（一种廉价但相对惰性的三氟甲基（CF）源），实现了敏感（杂）芳烃的脱羧三氟甲基化。由静电吸附在正钼掺杂的三氧化钨（WO）光阳极上的三氟乙酸根阴离子形成的离子屏蔽层，可防止底物与光生空穴之间发生不期望的电子转移。所开发方法的实用性通过稳健的光阳极稳定性（约380小时）、良好的底物范围以及使用光电化学流通池实现100克规模合成的放大能力得到了证明。
