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.