A highly efficient method for the facile access of isoquinolines and isoquinoline N-oxides via a Cu(i)-catalyzed intramolecular cyclization of (E)-2-alkynylaryl oxime derivatives in water has been developed. This protocol was performed under simple and mild conditions without organic solvent, additives or ligands. By switching on/off a hydroxyl protecting group of oximes, the selective N-O/O-H cleavage
Iodine-mediated electrophilic cyclization of 2-alkynylbenzaldoximes leading to the formation of iodoisoquinoline N-oxides
作者:Zhibao Huo、Hisamitsu Tomeba、Yoshinori Yamamoto
DOI:10.1016/j.tetlet.2008.07.061
日期:2008.9
Reaction of 2-alkynylbenzaldoximes 1 with 5 equiv of iodine in EtOH at room temperature gives the corresponding iodoisoquinoline N-oxides 2 in good to excellent yields. The cyclization proceeds very smoothly and quickly without any additives such as bases under very mild reaction conditions. (C) 2008 Elsevier Ltd. All rights reserved.