Galenko Ekaterina E, Kryukova Mariya A, Novikov Mikhail S, Khlebnikov Alexander F
Saint Petersburg State University, Institute of Chemistry, 7/9 Universitetskaya Naberezhnaya, St. Petersburg 199034, Russia.
J Org Chem. 2021 May 7;86(9):6888-6896. doi: 10.1021/acs.joc.1c00286. Epub 2021 Apr 13.
A four-step quasi one-pot procedure for the preparation of fully substituted nicotinates from ketone enamines and 4-methylideneisoxazol-5-ones has been developed. The reaction sequence involves (1) reaction of 4-methylideneisoxazol-5-ones with ketone enamines with the formation of isoxazole-5-ols, (2) their O-methylation with diazomethane, (3) hydrogenative cleavage of the O-N bond in 5-methoxyisoxazoles under action of Mo(CO)/HO and simultaneous isomerization and condensation of the formed enamines, with the formation of dihydropyridines, and (4) aromatization of the latter.
已开发出一种由酮烯胺和4-亚甲基异恶唑-5-酮制备全取代烟酸酯的四步准一锅法。该反应序列包括：(1) 4-亚甲基异恶唑-5-酮与酮烯胺反应生成异恶唑-5-醇；(2) 用重氮甲烷对其进行O-甲基化；(3) 在Mo(CO)/HO作用下，5-甲氧基异恶唑中的O-N键发生氢化裂解，同时所生成的烯胺进行异构化和缩合反应，生成二氢吡啶；(4) 后者进行芳构化。
