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Synthesis of Highly Substituted Imidazo[1,5‐ a ]quinoxalines Through a Multicomponent Reaction Followed by Deprotection–Cyclization
Author(s) -
Sashidhara Koneni V.,
Prasad Dodda. Ranga,
Upadhyay Akanksha,
Reddy Palnati Gopala,
Modukuri Ram K.,
Kant Ruchir
Publication year - 2016
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.201600285
Subject(s) - chemistry , trifluoromethanesulfonate , trifluoroacetic acid , catalysis , combinatorial chemistry , reaction conditions , lewis acids and bases , organic chemistry , aryl , lewis acid catalysis , medicinal chemistry , alkyl
An operationally simple and efficient, one‐pot, two‐step methodology has been developed for the assembly of medicinally important imidazo[1,5‐ a ]quinoxalines. The protocol involves the multicomponent reaction of aryl aldehydes, ortho ‐ N ‐Boc‐phenylenediamines and azidochalcones in the presence of erbium triflate as a Lewis acid catalyst, followed by deprotection–cyclization with 10% trifluoroacetic acid, furnishing the desired compounds in moderate to good yields. By virtue of their convergence, two aromatic rings and four new bonds are generated during the course of this reaction protocol. The structure of one of the compounds was proved by X‐ray crystallography.