Sequential C–H Aroylation and Formal [4 + 2] Cycloaddition of Naphthalenes with Aroylfluorides and Styrenes

While single-electron transfer (SET) and energy transfer
(EnT)
processes have each made significant contributions to photochemical
catalysis, their combination in an SET–EnT sequence remains
underexplored. Here, we report a sequential activation strategy that
merges SET and EnT catalysis to achieve the dearomatization of naphthalene
derivatives through sequential C–H activation and [4 + 2] cycloaddition,
enabling the efficient construction of bridged polycyclic frameworks.
Key to this approach is an SET-mediated, NHC-catalyzed prefunctionalization
of the naphthalene ring, which modulates its triplet energy, thereby
facilitating selective EnT-driven cycloaddition with alkenes. This
strategy provides precise control over reactivity, expands the scope
of visible-light-mediated catalysis, and offers a robust platform
for the synthesis of complex three dimensional (3D) molecular architectures
from simple precursors.