Synthesis of Isoquinolines and Pyridines by the Palladium/Copper-Catalyzed Coupling and Cyclization of Terminal Acetylenes and Unsaturated Imines: The Total Synthesis of Decumbenine B
作者:Kevin R. Roesch、Richard C. Larock
DOI:10.1021/jo010579z
日期:2002.1.1
have been developed. However, aryl-, vinylic-, and alkyl-substituted acetylenes undergo palladium-catalyzed coupling and subsequent copper-catalyzed cyclization in excellent yields. The total synthesis of the isoquinoline natural product decumbenine B has been accomplished in seven steps and 20% overall yield by employing this palladium-catalyzed coupling and cyclization methodology.
在钯催化剂的存在下,通过将末端乙炔与邻碘联苯甲醛和3-卤-2-烯醛的叔丁基亚胺偶联,然后将铜催化中间体中间体的环化反应,可以制备出单取代的异喹啉和吡啶,具有良好的产率。亚氨基炔。此外,通过铜催化亚氨基炔的环化反应,异氰酸喹啉杂环化合物的收率很高。环化条件的选择取决于所用末端乙炔的性质,因为只有芳基和烯基乙炔在已开发的钯催化的反应条件下环化。但是,芳基,乙烯基和烷基取代的乙炔经过钯催化的偶联反应,随后以铜催化的环化反应,收率极高。