Efficient synthesis of novel thieno[3,2-b]-, [2,3-c]- and [3,2-c]pyridones by Sonogashira coupling of bromothiophenes with terminal alkynes and subsequent intramolecular C–N bond-forming reaction

The coupling of bromothiophenes with terminal alkynes using triethylamine or diisopropyl amine under Sonogashira conditions (PdCl₂(PPh₃)₂, CuI) followed by subsequent addition of amines or ammonium to the intermediate thienyl acetylenes represents a novel access to a wide range of thieno[3,2-b]-, [2,3-c]-, and [3,2-c]pyridones under basic conditions and in excellent yields.

Iaroshenko V. O.; Ali S.; Babar T. M.; Abbasi M. S. A.; Sosnovskikh V. Y.; Villinger A.; Tolmachev A.; Langer P.
Tetrahedron 2013, 69 (15), 3167-3181
DOI: 10.1016/j.tet.2013.02.069