Chemoselectivity and the curious reactivity preferences of functional groups.

Achieving high levels of chemoselectivity has been the Achilles' heel of chemical synthesis. The excitement generated by the successful realization of chemoselective strategies underscores the painstaking efforts to define a set of conditions conducive to selection among the available reaction pathways. We discuss in this Review various aspects of chemoselectivity that have been addressed in a range of synthetic methods over the past decade. We have focused on the proposed mechanistic basis of the reactions under consideration in an attempt to categorize them and highlight the key concepts that have been emerging on the basis of these studies. Our overview of recent advances in chemoselective processes suggests that significant progress has been made, but a lot of challenges lie ahead.