A great number of heterocyclic quinones have been extensively investigated for their biological activity and especially for their noticeable antitumor activity. Mitomycins 1, 2, 3 and 4 and the corresponding mitosenes (such as EO9 5 and many indole analogues 6 ) are well-known examples of reductive alkylating quinones (Scheme 1). The reductive alkylation process involves the formation of an alkylating quinone methide species upon reduction of the quinone and elimination ...