title: Novel succinct routes to Quinoxalines and 2-Benzimidazolylquinoxalines via the Ugi reaction.
abstract: This communication reveals a unique, user-friendly, concise two-step, one-pot protocol for the synthesis of highly substituted quinoxalines. Conducting the Ugi reaction with appropriately functionalized classical Ugi reagents with subsequent acid treatment of the Ugi adduct affords collections of diversified quinoxalines in good to excellent yields. The methodology exploits what may be viewed as a 'convertible carboxylic acid', which in addition may be captured in an intramolecular sense to generate structurally complex 2-benzimidazolylquinoxalines in a mere two steps.
authors.affiliation: College of Pharmacy, BIO5 Oro Valley, The University of Arizona, 1580 E. Hanley Blvd, Oro Valley, AZ 85737, USA.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Ayaz
authors.affiliation: College of Pharmacy, BIO5 Oro Valley, The University of Arizona, 1580 E. Hanley Blvd, Oro Valley, AZ 85737, USA.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Xu
authors.affiliation: College of Pharmacy, BIO5 Oro Valley, The University of Arizona, 1580 E. Hanley Blvd, Oro Valley, AZ 85737, USA. ; Department of Chemistry and Biochemistry, The University of Arizona, Tucson, AZ 85721, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Hulme
keywords: Acyl Transfer; Benzimidazole; Post-condensation modifications; Quinoxaline; Ugi reaction