The first catalytic direct C–H arylation on C2 and C3 of thiophene ring applied to thieno-pyridines, -pyrimidines and -pyrazines

Abstract

A practical one-pot procedure for the preparation of diverse thieno[3,2-<i>d</i>]pyrimidines is reported here for the first time. This two-step process via C–H activation in position C-2 of thiophene led to the development of an improved methodology for the synthesis of numerous compounds. This new methodology is an efficient alternative to the conventional methods currently applied. The C–H activation of the thiophene C-3 position was also achieved and can be selective. The optimized conditions can also be applied to thienopyridines and thienopyrazines.