Visible-Light-Triggered Oxidative C-H Aryloxylation of Phenolic Amidines; Photocatalytic Preparation of 2-Aminobenzoxazoles
Vishnu P. Srivastava*, Lal Dhar S. Yadav*
*Green Synthesis Lab, Department of Chemistry, University of
Allahabad, Allahabad 211 002, India, Email: prabhaker7777
yahoo.com,
ldsyadavhotmail.com
V. P. Srivastava, L. D. S. Yadav, Synlett, 2013, 24, 2758-2762.
DOI: 10.1055/s-0033-1340150
Abstract
Visible light efficiently mediates a mild intramolecular oxidative cyclization of o-hydroxy-N-aryl-N,N-dialkylformamidines leading to 2-aminobenzoxazole derivatives in excellent yields in the presence of only 1 mol% tris(2,2′-bipyridine)ruthenium(II) as a photoredox catalyst and air as terminal oxidant.
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Key Words
visible light, ruthenium, photoredox catalysis, intramolecular cyclization, oxidative ring-closing, benzoxazoles, oxygen
ID: J60-Y2013
