Department of Chemistry, Huaibei Normal University, Huaibei, Anhui, P R China.
J Org Chem. 2011 Jun 3;76(11):4692-6. doi: 10.1021/jo200317f. Epub 2011 May 4.
In this paper, a novel and applicable synthesis of benzofurans from commercially available phenols and propiolate through the direct oxidative cyclization has been developed. In the presence of Pd(OAc)(2)/PPh(3) and CF(3)CO(2)Ag, (E)-type 3-phenoxyacrylates underwent reaction smoothly to generate the corresponding benzofurans in good yields in benzene at 110 °C under the air pressure. In addition, this transformation of phenols into benzofurans can also be carried out in one pot. The process was simple and efficient. A tentative mechanism of palladium-catalyzed oxidative cyclization of 3-phenoxyacrylates was proposed.
本文开发了一种新颖且适用的从市售酚和丙炔酸酯通过直接氧化环化合成苯并呋喃的方法。在 Pd(OAc)(2)/PPh(3) 和 CF(3)CO(2)Ag 的存在下，（E）-型 3-苯氧基丙烯酸酯在苯中于 110°C、空气压力下反应顺利，以良好的收率生成相应的苯并呋喃。此外，酚到苯并呋喃的这种转化也可以一锅进行。该过程简单高效。提出了钯催化 3-苯氧基丙烯酸酯氧化环化的可能机理。
