Copper-catalyzed cyclization reactions for the synthesis of alkaloids.

Copper-mediated Ullmann type transformations have recently evolved as useful and valuable synthetic tools in organic synthesis. If newly developed catalytic systems are readily available, inexpensive, and tolerate most functional groups, they also provide new opportunities in natural product synthesis since they allow new and efficient retrosynthetic disconnections. They are also especially convenient for the development of straightforward cyclization and macrocyclization procedures. The present article showcases some examples of copper-catalyzed cyclization reactions for the synthesis of alkaloids we have recently developed.