Synthesis of 2 H-Thiopyrans by Rhodium(II) Acetate-Catalyzed Reaction of 4-Amino-2,5-dihydro-3-thiophenecarbonitriles with a-Diazocarbonyl Compounds II [1]
作者:Kenji Yamagata、Fumi Okabe、Motoyoshi Yamazaki
DOI:10.1007/s007060170087
日期:2001.6
The reaction of 4-amino-2,5-dihydro-2- and -5-methyl-3-thiophenecarbonitriles with α-diazocarbonyl compounds in the presence of rhodium(II) acetate gave regioselectively 4-cyano-2 H -thiopyrans (C2-S insertion) in moderate to good yields; 5-cyano-2 H -thiopyrans (C5-S insertion) were not isolated. The starting compounds were synthesized by reaction of tetrahydro-2- and -5-methyl-4-oxo-3-thiophenecarbonitriles
4-氨基-2,5-二氢-2-和-5-甲基-3-噻吩甲腈在乙酸铑(II)的存在下与α-重氮羰基化合物的反应,产生区域选择性的4-氰基-2 H- 硫代 吡喃(C 2 -S插入)以中等至良好的产量;未分离出5-氰基-2 H- 硫代 吡喃(C 5 -S插入)。在乙醇中存在甲酸的情况下,通过使四氢-2-和-5-甲基-4-氧代-3-噻吩甲腈与吗啉,哌啶和吡咯烷反应来合成起始化合物。