A metal-free method for direct synthesis of functionalized β-ketoenamines.

A new method for direct synthesis of β-ketoenamines was developed by a BF3•OEt2-catalyzed cyclization of 1-iodoalkyne and α-keto acid followed by an amine-mediated ring-opening in one-pot. Its metal-free conditions allowed the easy synthesis of those products bearing the transition metal-sensitive functional groups. Its three-component process achieved wide range of functionalized products.