Thermal Aza-Bergman Cyclization ofo-Alkynylaryl Isocyanides with Organic Diselenide, Ditelluride, and Iodine Leading to 2,4-Difunctionalized Quinolines
When a mixture of o-alkynylaryl isocyanides and organic dichalcogenides such as diselenides or ditellurides was irradiated with light of wavelength over 300 or 400 nm, the intramolecular cyclization of the isocyanides took place to afford the corresponding 2,4-bischalcogenated quinolines selectively. The photochemical cyclization of 2-(phenylethynyl)phenyl isocyanide could also proceed in the presence of hydrogen transfer reagents such as tris(trimethylsilyl)silane, tributylgermyl hydride, alkanethiols, and benzeneselenol, providing the corresponding 3-phenylquinoline as the result of 2,4-dihydrogenation.
Thermal Aza-Bergman Cyclization of<i>o</i>-Alkynylaryl Isocyanides with Organic Diselenide, Ditelluride, and Iodine Leading to 2,4-Difunctionalized Quinolines
作者:Takenori Mitamura、Akiya Ogawa
DOI:10.1246/bcsj.20110041
日期:2011.7.15
Thermal aza-Bergman cyclization of o-alkynylaryl isocyanides has been achieved in the presence of organic dichalcogenides. The reactions can be induced upon heating at 40 °C to afford the corresponding 2,4-dichalcogenated quinolines. In addition, similar conditions can be also employed with iodine to form 2,4-diiodoquinolines.