Improved Methodologies for the Preparation of Highly Substituted Pyridines
作者:Yolanda Fernández Sainz、Steven A. Raw、Richard J. K. Taylor
DOI:10.1021/jo0518304
日期:2005.11.1
Two separate strategies have been developed for the preparation of highly substituted pyridines from 1,2,4-triazines via the inverse-electron-demand Diels−Alder reaction: a microwave-promoted, solvent-free procedure and a tethered imine-enamine (TIE) approach. Both routes avoid the need for a discrete aromatization step and offer significant advantages over the classical methods, giving a wide variety