Synthesis of 1,2,3-Triazolo-Fused Allocolchicine Analogs via Intramolecular Oxidative Biaryl Coupling

A novel series of 1,2,3-triazolo-fused allocolchicine analogs is described. The strategy to prepare these analogs involves two steps: The first step is the synthesis of 1,2,3-triazole derivatives using our previously reported triazolization method, and in the second step, cyclization between two aromatic rings occurs by using the combination of PIFA and BF₃·Et₂O as an oxidative coupling reagent. Furthermore, the diversity of aromatic rings and functional groups is explored in order to obtain seven- and eight-membered ring systems with medicinal chemistry interest.