A palladium-catalyzed [2 + 2 + 1] domino annulation of 3-iodochromones, α-bromo carbonyl compounds, and tetracyclododecene (TCD) is described. This approach provides a facile, efficient and atom-economical route to a variety of chromone-containing polycyclic compounds bearing fused/bridged-ring systems in good yields (up to 81%) with excellent diastereoselectivities (99 : 1 dr in all cases).
![Graphical abstract: Synthesis of chromone-containing polycyclic compounds via palladium-catalyzed [2 + 2 + 1] annulation](http://hg.y866.cn/compound/lib/scimg/usr/1/C9OB02690H.jpg)