Dong Jun, Du Hongguang, Xu Jiaxi
State Key Laboratory of Chemical Resource Engineering, Department of Organic Chemistry, College of Chemistry, Beijing University of Chemical Technology Beijing 100029 People's Republic of China
RSC Adv. 2019 Aug 12;9(43):25034-25038. doi: 10.1039/c9ra03563j. eCollection 2019 Aug 8.
Polysubstituted furans were prepared in moderate to good yields from various sulfur ylides and alkyl acetylenic carboxylates. The direct reactions of dimethylsulfonium acylmethylides with dialkyl acetylenedicarboxylates afforded dialkyl furan-3,4-dicarboxylates through a tandem sequence of Michael addition, intramolecular nucleophilic addition, 4π ring opening, intramolecular Michael addition, and elimination. The method was extended to synthesize furan-3-carboxylate, -2,4-dicarboxylates, and -2,3,4-tricarboxylates as well. The current method provides a direct and simple strategy in the synthesis of structurally diverse polysubstituted furans with mono to tricarboxylate groups from safe and readily available dimethylsulfonium acylmethylides and different alkyl acetylenic carboxylates.
通过各种硫叶立德和炔基羧酸酯，以中等至良好的产率制备了多取代呋喃。二甲基硫鎓酰基甲基化物与二烷基乙炔二羧酸酯的直接反应通过迈克尔加成、分子内亲核加成、4π开环、分子内迈克尔加成和消除的串联序列，得到二烷基呋喃-3,4-二羧酸酯。该方法还扩展到合成呋喃-3-羧酸酯、-2,4-二羧酸酯和-2,3,4-三羧酸酯。目前的方法提供了一种直接且简单的策略，用于从安全且易于获得的二甲基硫鎓酰基甲基化物和不同的炔基羧酸酯合成具有单羧酸酯至三羧酸酯基团的结构多样的多取代呋喃。
