Diastereoselective construction of azabicyclo[3.1.0]hexan-2-ones via a base-mediated cascade annulation of β-oxo-acrylamides with vinylsulfonium salts

Herein, a DBU-mediated cascade annulation of β-oxo-acrylamides with vinylsulfonium salts has been achieved under mild reaction conditions. This methodology not only provides a direct route for the synthesis of highly functionalized azabicyclo[3.1.0]hexan-2-one derivatives in satisfactory results (65-95% yields with >20 : 1 drs) but also expands the reaction repertoire involving β-oxo-acrylamides. Moreover, this current protocol features transition-metal-free and mild conditions, easy operation, and broad functional group tolerance.