Lewis Acid Catalyzed Cycloaddition of Bicyclobutanes with Ynamides for the Synthesis of Polysubstituted 2-Amino-bicyclo[2.1.1]hexenes.

Synthesis of bicyclic scaffolds has gained significant attention in drug discovery due to their potential to mimic benzene bioisosteres. Here, we present a mild and scalable Sc(OTf)-catalyzed [3+2] cycloaddition of bicyclo[1.1.