Experimental and Theoretical Analyses of Azulene Synthesis from Tropones and Active Methylene Compounds: Reaction of 2-Methoxytropone and Malononitrile

• Published in: Journal of organic chemistry Vol. 77; no. 12; pp. 5318 - 5330
• Main Authors: Machiguchi, Takahisa, Hasegawa, Toshio, Yamabe, Shinichi, Minato, Tsutomu, Yamazaki, Shoko, Nozoe, Tetsuo
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 15.06.2012; Amer Chemical Soc
• Subjects: Alicyclic compounds; Alicyclic compounds, terpenoids, prostaglandins, steroids; azulene; chemical reactions; chemical structure; Chemistry; Chemistry, Organic; Condensed benzenic and aromatic compounds; Exact sciences and technology; Heterocyclic compounds; Heterocyclic compounds with o, s, se, te hetero atom and condensed derivatives; imines; Kinetics and mechanisms; Lewis bases; nuclear magnetic resonance spectroscopy; Organic chemistry; Physical Sciences; Preparations and properties; Reactivity and mechanisms; Science & Technology; THERMAL CYCLOADDITION REACTIONS; QUINONES; 3-BROMO-1,5-AZULENEQUINONE; ZUR KENNTNIS; DERIVATIVES; Reaction intermediate; One pot reaction; Nitrile; Furan derivatives; NMR spectrometry; Oxygen heterocycle; Meisenheimer complex; Azulene derivatives; Anions; Amine; Reaction mechanism; Malononitrile; Aromatic compound; Chemical synthesis; Low temperature; Theoretical study; Imine; Active methylene compound; Cyclization; Density functional method; Carboxamide; Detection; Nucleophilic substitution; Tropones; Nucleophilic addition; Dinitrile; Successive reaction

A representative azulene formation from an active troponoid precursor (2-methoxytropone) and an active methylene compound (malononitrile) has been analyzed both experimentally and theoretically. 2H-Tracer experiments using 2-methoxy[3,5,7-2H3]tropone (2-d 3) and malononitrile anion give 2-amino-1,3-...