Chemodivergent Catalytic Enantioselective Ring Opening of Azabicyclo[1.1.0]butanes

Azabicyclo[1.1.0]butanes (ABBs) have never been utilized in an enantioselective transformation. We have now developed an enantioselective Ir-catalyzed N-allylation triggered chemodivergent ring opening of azabicyclo[1.1.0]butyl carbinols. In addition to promoting Ir-catalyzed allylic amination, the Lewis acids (along with the reaction medium) play decisive roles in controlling the chemoselectivity of these reactions (i.e., spiroannulation vs semipinacol rearrangement). Enantioenriched N-allylic 3-acyl azetidines, bearing an all-carbon quaternary center and N-allylic spiroepoxy azetidines can be accessed in a chemoselective manner. To the best of our knowledge, this report represents the first enantioselective transformation involving azabicyclo[1.1.0]butanes.