AgOTf and TfOH co-catalyzed isoquinoline synthesis via redox reactions of O-alkyl oximes
摘要:
Under AgOTf and Bronsted acid co-catalysis, O-alkyl o-alkynylbenzaldoxime derivatives undergo a cyclization-induced N-O cleavage to produce isoquinolines with the simultaneous oxidation of O-alkyl group. This redox-based method provides a general access to diverse isoquinoline-derived heterocycles that are simple, efficient, and tolerant of various functional groups from readily available and hydrolytically stable oxime precursors. (C) 2009 Elsevier Ltd. All rights reserved.
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