Efficient synthesis of 2-acylquinolines based on an aza-vinylogous Povarov reaction. Issue 4 (24th February 2016)

• Record Type: Journal Article
• Authors: Bianchini, Giulia; Ribelles, Pascual; Becerra, Diana; Ramos, M. Teresa; Menéndez, J. Carlos
• Is Part Of: Organic chemistry frontiers. Volume 3:Issue 4(2016:Apr.)
• Page Start: 412
• Page End: 422
• Publication Date: 2016-02-24
• Subjects: Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1039/c6qo00037a
• Languages: English
• ISSNs: 2052-4110

Abstract

Abstract : Povarov-type chemistry gives ready access to 2-acylquinolines. Abstract : The aza-vinylogous Povarov reaction between α-ketoimines and α, β-unsaturated dimethylhydrazones in the presence of indium trichloride affords 2-acyl-4-alkyl-4-dimethylhydrazonomethyl-1, 2, 3, 4-tetrahydroquinolines with good cis / trans diastereoselectivities. These compounds were readily transformed into highly substituted 2-acylquinolines using a two-reaction sequence involving the oxidative generation of a C-4 nitrile group, followed by its elimination under thermal conditions. Alternatively, a one-pot protocol based on the reaction of hydrazones with magnesium monoperoxyphthalate hexahydrate in refluxing methanol afforded the target 2-acylquinolines in good to excellent yields. This methodology was also extended to the preparation of 2-arylquinolines.