Three Novel Sequential Reactions for the Facile Synthesis of a Library of Bisheterocycles Possessing the 3-Aminoimidazo[1,2-a]pyridine Core Catalyzed by Bismuth(III) Chloride
作者:Aziz Shahrisa、Somayeh Esmati
DOI:10.1055/s-0032-1318221
日期:——
Novel, one-pot, two-step, sequential protocols for the synthesis of 1,4-phenylene bisheterocyclic compounds have been developed. Successive sequencing of the Groebke-Blackburn-Bienayme reaction with Ugi-azide, Hantzsch and Biginelli reactions results in rapid and efficient formation of bisheterocyclic compounds. A simple, fast and high yielding method for the synthesis of 3-aminoimidazo[1,2-a]pyridines catalyzed by bismuth(III) chloride under solvent-free conditions is reported. Bismuth(III) chloride is also an efficient catalyst for the Ugi-azide reaction under solvent free conditions.
Diverse Oxidative C(sp<sup>2</sup>)–N Bond Cleavages of Aromatic Fused Imidazoles for Synthesis of α-Ketoamides and <i>N</i>-(pyridin-2-yl)arylamides
An efficient and chemoselective C(sp(2))-N bond cleavage of aromatic imidazo[1,2-a]pyridine molecules is developed. A broad scope of amide compounds such as alpha-ketoamides and N-(pyridin-2-yl)arylamides are afforded as the final products in up to quantitative yields. Diverse C-N bond cleavages are controlled by the oxidative species used in this transformation, with various amide products afforded in a chemoselective fashion. A preliminary study indicated that some alpha-ketoamides exhibit anti-Tobacco Mosaic Virus activity for potential use in plant protection.