Cobalt-Catalyzed Enantioselective Hydroalkylation of Oxa- or Azabicyclic Alkenes

Bridged bicyclic structures, exemplified by rigid oxa- and azabicyclic alkanes, are pivotal scaffolds in drug design and natural product synthesis due to their three-dimensional architecture and inherent ring strain. Functionalization of readily available bicyclic alkenes provides a potential pathway to synthesizing molecules with complex cyclic structures. However, strained bicyclic alkenes exhibit thermodynamic reactivity driven by strain energy release, which predominantly favors ring-opening pathways. In contrast, ring-retentive hydroalkylation─a direct method for synthesizing complex bridged bicyclic architectures─remains underdeveloped. Here, we present a cobalt-catalyzed enantioselective hydroalkylation strategy for bicyclo2.2.1alkenes that enables ring-retentive addition while constructing tertiary carbon stereocenters within oxa- or azabicyclic frameworks. Mechanistic investigations revealed that the hydrometalation of alkenes serves as the selectivity-determining step, where noncovalent interactions between the catalyst and substrate govern stereoisomeric differentiation. The protocol demonstrates broad compatibility with diverse alkyl iodides and bicyclo2.2.1alkenes, facilitating late-stage functionalization of bioactive molecules and enabling the efficient synthesis of antifungal agents with potent activity.