Bicyclo[2.2.1]heptane frameworks represent a privileged structural motif
prevalent in numerous natural products and bioactive molecules. We
report a one-step, highly enantioselective and diastereoselective
reductive protocol for the synthesis of oxa- and
aza-bicyclo[2.2.1]heptanes, enabled by [cobalt]/[photoredox] (Co/PC)
catalysis. This methodology exploits heterobicyclic strained olefins as π-coupling
partners to directly access enantiomerically enriched
bicyclo[2.2.1]heptanes from a wide range of alkynes, including terminal
alkynes, propargylic alcohols, and internal alkynes. Mechanistic
investigations, supported by DFT calculations, reveal that the oxidative
coupling between the alkyne and alkene constitutes both the enantio-
and rate-determining step. DIPEA serves as an efficient electron-donor,
while the in situ-generated secondary ammonium salt acts as a competent
proton source.