作者:Kazuhiro Kobayashi、Toshikazu Ogata、Kazuna Miyamoto、Osamu Morikawa、Hisatoshi Konishi
DOI:10.3987/com-03-9790
日期:——
7-dioxo-4,7-dihydrobenzo[b]thiophene-2-carboxylates (3 ). These acylated benzothiophenquinone derivatives were transformed in one-pot to 4,8-dioxo-4,8-dihydrobenzo[1,2-b:5,4-b']dithiophene-2,6-dicarboxylates (5) by treatment with mercaptoacetates, followed by 1-trimethylsilylimidazole-mediated cyclization and cerium(IV) ammonium nitrate (CAN) oxidation.
4,7-Dioxo-4,7-dihydrobenzo[b]thiophene-2-carboxylates (1) 在辐照下与一系列醛在 5 位发生区域选择性酰化反应,得到相应的 5-acyl-4,7-dihydroxybenzo [b]噻吩-2-羧酸盐(2),然后用Ag 2 O氧化得到5-酰基-4,7-二氧代-4,7-二氢苯并[b]噻吩-2-羧酸盐(3)。这些酰化苯并噻吩醌衍生物在一锅中通过巯基乙酸盐处理转化为 4,8-二氧代-4,8-二氢苯并[1,2-b:5,4-b']二噻吩-2,6-二羧酸盐 (5) ,然后是 1-三甲基甲硅烷基咪唑介导的环化和硝酸铈 (IV) 铵 (CAN) 氧化。