title: Silver-Catalyzed Chemoselective [4+2] Annulation of Two Isocyanides: A General Route to Pyridone-Fused Carbo- and Heterocycles.
abstract: A silver-catalyzed chemoselective [4+2] annulation of aryl and heteroaryl isocyanides with α-substituted isocyanoacetamides was developed for the facile and efficient synthesis of 2-aminoquinolones, naphthyridines, and phenanthrolines. A mechanism for this multistep domino reaction is proposed on the basis of a13C-labeling experiment, according to which an unprecedented chemoselective heterodimerization of two different isocyanides generates an α-amidoketenimine intermediate, which undergoes 1,3-amino migration to form an α-imidoylketene, followed by 6 π electrocyclization.
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Normal University, Jinan, 250014, China.|Jilin Province Key Laboratory of Organic Functional Molecular Design and Synthesis, Department of Chemistry, Northeast Normal University, Changchun, 130024, China.
authors.forename: Zhongyan
authors.initials: Z
authors.lastname: Hu
authors.affiliation: Jilin Province Key Laboratory of Organic Functional Molecular Design and Synthesis, Department of Chemistry, Northeast Normal University, Changchun, 130024, China.
authors.forename: Jinhuan
authors.initials: J
authors.lastname: Dong
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Normal University, Jinan, 250014, China.|Jilin Province Key Laboratory of Organic Functional Molecular Design and Synthesis, Department of Chemistry, Northeast Normal University, Changchun, 130024, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Men
authors.affiliation: Jilin Province Key Laboratory of Organic Functional Molecular Design and Synthesis, Department of Chemistry, Northeast Normal University, Changchun, 130024, China.
authors.forename: Zhichen
authors.initials: Z
authors.lastname: Lin
authors.affiliation: Jilin Province Key Laboratory of Organic Functional Molecular Design and Synthesis, Department of Chemistry, Northeast Normal University, Changchun, 130024, China.
authors.forename: Jinxiong
authors.initials: J
authors.lastname: Cai
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Normal University, Jinan, 250014, China.|Jilin Province Key Laboratory of Organic Functional Molecular Design and Synthesis, Department of Chemistry, Northeast Normal University, Changchun, 130024, China.
authors.forename: Xianxiu
authors.initials: X
authors.lastname: Xu
keywords: [4+2] annulation; heterocycles; naphthyridines; phenanthrolines; quinolones