The scope for a range of sp2-sp2 coupling protocols to elaborate the phenyl-indole, indole- oxazole, oxazole-oxazole, and quaternary carbon units in the marine natural product diazonamide A 1 are described, leading to the synthesis of the benzofuran oxazoles 11a and 18, the benzofuran/biphenyl/indole 16, and the indole-bis-oxazole, 25.
