Li Sifan, Davies Paul W, Shu Wei
Shenzhen Grubbs Institute, Department of Chemistry, and Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology Shenzhen 518055 Guangdong China
School of Chemistry, University of Birmingham Edgbaston Birmingham B15 2TT UK.
Chem Sci. 2022 May 12;13(22):6636-6641. doi: 10.1039/d2sc01905a. eCollection 2022 Jun 7.
α-Arylated carboxylic acids, esters and amides are widespread motifs in bioactive molecules and important building blocks in chemical synthesis. Thus, straightforward and rapid access to such structures is highly desirable. Here we report an organophotocatalytic multicomponent synthesis of α-arylated carboxylic acids, esters and amides from exhaustive defluorination of α-trifluoromethyl alkenes in the presence of alkyltrifluoroborates, water and nitrogen/oxygen nucleophiles. This operationally simple strategy features a unified access to functionally diverse α-arylated carboxylic acids, esters, and primary, secondary, and tertiary amides through backbone assembly from simple starting materials enabled by consecutive C-F bond functionalization at room temperature. Preliminary mechanistic investigations reveal that the reaction operates through a radical-triggered three-step cascade process, which involves distinct mechanisms for each defluorinative functionalization of the C-F bond.
α-芳基羧酸、酯和酰胺是生物活性分子中广泛存在的结构单元，也是化学合成中的重要砌块。因此，直接且快速地获得此类结构是非常有必要的。在此，我们报道了一种有机光催化多组分合成方法，可在烷基三氟硼酸盐、水和氮/氧亲核试剂存在下，通过α-三氟甲基烯烃的完全脱氟反应制备α-芳基羧酸、酯和酰胺。这种操作简单的策略具有以下特点：通过在室温下由连续的C-F键官能化实现的简单起始原料的主链组装，统一地获得功能多样的α-芳基羧酸、酯以及伯、仲和叔酰胺。初步的机理研究表明，该反应通过自由基引发的三步串联过程进行，其中C-F键的每次脱氟官能化涉及不同的机理。
