An iodine-catalyzed aerobicoxidative formal [4+2] annulation for the construction of polyfunctionalized pyridines in one step has been developed through the green reaction system of catalytic amounts of molecular iodine and amine in combination with oxygen. Various ketones and aldehydes were able to react with different chalcones and β, γ-unsaturated α-ketoesters through this reaction strategy. Synthetically
An Isoxazole Strategy for the Synthesis of Fully Substituted Nicotinates
作者:Ekaterina E. Galenko、Mariya A. Kryukova、Mikhail S. Novikov、Alexander F. Khlebnikov
DOI:10.1021/acs.joc.1c00286
日期:2021.5.7
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
已经开发了一种四步半一锅法,用于从酮烯胺和4-甲基亚甲基异恶唑-5-酮制备完全取代的烟酸酯。反应顺序包括:(1)4-亚甲基异恶唑-5-酮与酮烯胺的反应,形成异恶唑-5-醇,(2)它们与重氮甲烷的O-甲基化,(3)O-N键的氢化裂解在5-甲氧基异恶唑中,在Mo(CO)6 / H 2 O的作用下,生成的烯胺同时异构化和缩合,形成二氢吡啶,以及(4)后者的芳构化。