Department of Chemistry , The University of Kansas , 1567 Irving Hill Road , Lawrence , Kansas 66045 , United States.
J Org Chem. 2019 Oct 4;84(19):12553-12561. doi: 10.1021/acs.joc.9b02092. Epub 2019 Sep 24.
Organic molecules bearing acetoxy moieties are important functionalities in natural products, drugs, and agricultural chemicals. Synthesis of such molecules via transition metal-catalyzed C-O bond formation can be achieved in the presence of a carefully chosen directing group to alleviate the challenges associated with regioselectivity. An alternative approach is to use ubiquitous carboxylic acids as starting materials and perform a decarboxylative coupling. Herein, we report conditions for a photocatalytic decarboxylative C-O bond formation reaction that provides rapid and facile access to the corresponding acetoxylated products. Mechanistic investigations suggest that the reaction operates via oxidation of the carboxylate followed by rapid decarboxylation and oxidation by Cu(OAc).
带有乙酰氧基部分的有机分子是天然产物、药物和农用化学品中的重要功能团。通过过渡金属催化的 C-O 键形成来合成这些分子,可以在精心选择的导向基团的存在下实现,以减轻与区域选择性相关的挑战。另一种方法是使用普遍存在的羧酸作为起始材料,并进行脱羧偶联。在此,我们报告了一种光催化脱羧 C-O 键形成反应的条件,该反应可快速、简便地获得相应的乙酰氧基产物。机理研究表明,该反应通过羧酸根的氧化,然后迅速脱羧和 Cu(OAc)的氧化来进行。