Regioselective Bromination of Thieno[2′,3′:4,5]pyrrolo[1,2-d][1,2,4]triazin-8(7H)-one and Sequential Suzuki Couplings

Regioselective bromination of thieno[2′,3′:4,5]pyrrolo[1,2-d][1,2,4]triazin-8(7H)-one at the 2- or 9-position was achieved by modulating the basicity of the reaction conditions. An anion-directed site-specific bromination mechanism was proposed. In addition, a one-pot bromination–Suzuki coupling protocol was developed for quick access of analogues at the 9-position.