AUTHOR=Yoon Jeong A , Lim Changjin , Han Young Taek 

TITLE=Preliminary Study on Novel Expedient Synthesis of 5-Azaisocoumarins by Transition Metal-Catalyzed Cycloisomerization

JOURNAL=Frontiers in Chemistry

VOLUME=8

YEAR=2020

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2020.00772

DOI=10.3389/fchem.2020.00772

ISSN=2296-2646

ABSTRACT=<p>A preliminary study to develop a novel synthetic method for 3-aryl-5-azaisocoumarins was performed herein. The cycloisomerization of <italic>N</italic>-pyranonyl propargylamines in the AgOTf-catalyzed system efficiently afforded the desired 3-aryl-5-azaisocoumarins in a highly regioselective manner. This unprecedented method is expected as an expedient alternative synthetic route to 5-azaisocoumarins because the regioselectivity problem is circumvented, and it is easier to introduce substituents on the pyridine ring compared to previously reported intramolecular lactonization approaches.</p>