作者:Shi-Xin Sun、Jun-Jie Wang、Zi-Jun Xu、Lu-Ya Cao、Zi-Fa Shi、Hao-Li Zhang
DOI:10.1016/j.tet.2014.04.005
日期:2014.6
Highly efficient organic reactions in water are important for designing environmental-friendly and low cost synthetic processes. Herein, we demonstrate an intermediate-in-water strategy for the heterogeneous synthesis of benzofurans in aqueous media. The cyclization reaction of 2-(phenylethynyl)phenol to 2-phenylbenzofuran cannot proceed in pure water. However, this reaction can be efficiently promoted by the formation of sparingly soluble intermediate in the presence of alkaline. Quantitative conversion of a variety of substrates to benzofuran derivatives has been achieved in the absence of noble metal catalyst. Other remarkable features including easy-isolation and purification of product, along with wide range of functional group tolerance render the methodology promising in the realm of green-synthesis. (C) 2014 Elsevier Ltd. All rights reserved.