河南科技大学刘普团队报道了烯胺酮和水杨醛串联氧化环化学发散合成苯并呋喃和2,3-二氢苯并呋喃。相关研究成果发表在2024年3月26日出版的《中国化学》。

苯并呋喃和2，3-二氢苯并呋喃的化学发散合成已经实现。在由DBDMH和K₂CO₃作为促进剂组成的反应体系下，控制条件使得烯胺酮和水杨醛的串联转化能够形成两组有价值的杂环。

成功的关键是确定反应参数，其中通过瞬时卤化偶联和取代过程形成的亚胺中间体，经历羟醛缩合/环化或亚胺水解/羟醛缩合。添加剂NH₄Cl或Fe₂（SO4）₃控制了该反应的独特选择性。在该反应中使用了广泛的烯胺酮和水杨醛，表现出优异的官能团耐受性和多功能性。

附：英文原文

Title: Chemodivergent Synthesis of Benzofurans and 2,3-Dihydrobenzofurans via Tandem Oxidative Annulation of Enaminones and Salicylaldehydes

Author: Xiyan Duan, Hui Li, Junqi Wang, Kun Liu, Meixin Shi, Weidong Lian, Ran Chen, Pu Liu

Issue&Volume: 2024-03-26

Abstract: Chemodivergent synthesis of benzofurans and 2,3-dihydrobenzofurans has been realized. Under a reaction system consisting of DBDMH and K2CO3 as promotors, controlled conditions enabled the formation of two sets of valuable heterocycles from the tandem transformation of enaminones and salicylaldehydes. The key to success was the identification of the reaction parameters, in which the imine intermediate which was formed by transient halogenation coupling and substitution processes underwent either aldol condensation/annulation or imine hydrolysis/aldol condensation. The additives NH4Cl or Fe2(SO4)3 controlled the unique selectivity of this reaction. A broad substrate scope of enaminones and salicylaldehydes has been employed in this reaction, demonstrating excellent functional group tolerance and versatility.

DOI: 10.1002/cjoc.202400082

Source: https://onlinelibrary.wiley.com/doi/full/10.1002/cjoc.202400082