methodology for the synthesis of 5-selenyl/sulfenyl nicotinates involving copper-catalyzed organochalcogenyl aza-annulation of enynyl azide with diorganyl-dichalcogenides has been described. This method offers difunctionalization of alkynes via regioselective intramolecular chalcogenoamination in one pot to provide substituted 5-chalcogenyl nicotinates in good to excellent yields. The resulting nicotinates
Oxidative Aza-Annulation of Enynyl Azides to 2-Keto/Formyl-1<i>H</i>-pyrroles
作者:Chada Raji Reddy、Sujatarani A. Panda、Andhavaram Ramaraju
DOI:10.1021/acs.joc.6b02468
日期:2017.1.20
the intramolecular oxidative aza-annulation of enynyl azides is reported for the first time. It involves a sequential carbon–nitrogen/carbon–oxygen bond formations, and the combination of AuCl3 with AgSbF6 was identified as a suitable reagent system to promote the present reaction. The required enynyl azides are readily prepared from Morita–Baylis–Hillman (MBH) acetates of acetylenic aldehydes.