It is important to bear in mind that most of the indolocarbazoles, which exhibit potent biological activities, have substituents on the benzene portion of the core. Despite the synthetic efforts for indolocarbazoles mentioned above, there remains a need for a flexible and efficient route. Previously, we reported the synthesis of quino[4,3-b]carbazole analogs,(18) a precursor of calothrixin(19) which involved a thermal electrocyclization in the key step. In a ...