Regioselective metal-free one-pot synthesis of functionalized 2-aminothiophene derivatives.

ABSTRACT

A facile metal-free synthesis of 2-aminothiophene derivatives by the reaction of 2-ynals with thioamides in alcohols has been developed. This transformation allows the assembly of 2-aminothienyl ether derivatives via a well-designed aldol condensation/regioselective intramolecular cyclization/conjugate addition cascade reaction and provides a straightforward synthetic protocol for constructing 2,3,5-trisubstituted 2-aminothiophenes.