作者:Chen, Yixin、He, Yuchen、Gao, Yong、Xue, Jiakun、Qu, Wei、Xuan, Jun、Mo, Yiming
DOI:10.1126/science.adm8902
日期:——
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
3
) source. An ion-shielding layer, formed by trifluoroacetate anions electrostatically adsorbed on a positive molybdenum-doped tungsten trioxide (WO
3
) 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.
电化学提供了一种合成高附加值精细化学品的可持续合成路线,但常常受到电极与目标位点以外的氧化还原敏感功能团之间竞争性电子转移的限制。本文中,我们描述了一种基于离子屏蔽的异质光电催化策略,通过施加传质限制来反转由热力学决定的电子转移顺序。该策略通过使用三氟乙酸盐(一种廉价且相对惰性的三氟甲基(CF3)来源)实现了对敏感杂环芳烃的脱羧三氟甲基化。该策略利用三氟乙酸根阴离子在正极性掺钼三氧化钨(WO3)光阳极上的静电吸附形成的离子屏蔽层,阻止了底物与光生空穴之间的不期望电子转移。通过使用光电化学流动池,我们展示了该方法的实用性,包括稳健的光阳极稳定性(约380小时)、良好的底物适用范围以及放大的能力,以实现100克规模的合成。