title: Reaction cascades initiated by nucleophilic attack of heteropentalene mesomeric betaine and nitrogen-rich mesoionic tetrazolium-5-amides on electron-deficient unsaturated compounds. Synthesis of novel heterocyclic systems.
abstract: The reactions of heteropentalene mesomeric betaine 1 and nitrogen-rich mesoionic tetrazolium-5-amides 4, 11 and 16-18 with electron-deficient unsaturated compounds have been studied. Novel heterocyclic systems, tetrazolo[4,5-a][1,7]benzodiazonine inner salt 2 and 3-oxo-3,7-dihydro-2H-pyrazolo[3,4-b]pyridine 5, have been synthesized by the reactions of dimethyl acetylenedicarboxylate with 1 and tetrazolium-5-anilide 4, respectively, and fully characterized by X-ray crystallography. It has been found that the reactions of other tetrazolium-5-amides are also initiated by the nucleophilic addition of the electron-rich amide nitrogen to the electron-deficient unsaturated compounds.
authors.affiliation: Department of Applied Chemistry, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan. araki@ach.nitech.ac.jp
authors.forename: Shuki
authors.initials: S
authors.lastname: Araki
authors.forename: Masashi
authors.initials: M
authors.lastname: Kuzuya
authors.forename: Kenji
authors.initials: K
authors.lastname: Hamada
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Nogura
authors.forename: Nayumi
authors.initials: N
authors.lastname: Ohata
mesh_terms: D000577:Amides / Q000737:chemistry*; D001391:Azo Compounds / Q000138:chemical synthesis; D001622:Betaine / Q000031:analogs & derivatives* / Q000737:chemistry; D018360:Crystallography, X-Ray; D003500:Cyclization; D004563:Electrochemistry; D006571:Heterocyclic Compounds / Q000138:chemical synthesis*; D008958:Models, Molecular; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry; D011725:Pyridines / Q000138:chemical synthesis; D013237:Stereoisomerism
chemical_list: D000577:Amides; D001391:Azo Compounds; D006571:Heterocyclic Compounds; D011725:Pyridines; D001622:Betaine; D009584:Nitrogen