Irradiation of Bifunctional Masked Ketone Pro-Aromatics Unveils Autocatalytic EDA Complex-Driven Radical Generation

Pro-aromatic dihydroquinazolinones (DHQZ) are masked ketones capable of group transfer by leveraging their aromatic stabilization energy (ASE) to promote C–C bond cleavage, typically initiated by photocatalysts and transition metals, generating a radical and quinazolinone as a by-product. Here, we present an indirect autocatalytic electron donor-acceptor (EDA) complex mode to enable an initiator-free activation and radical generation for pro-aromatic DHQZ. Mechanistic studies revealed that the aggregation of DHQZ and quinazolinone was enhanced by Zn(OTf)2, while the by-product quinazolinone enabled autocatalysis as an indirect autocatalyst. This strategic design also repurposed the typically discarded redox auxiliary in EDA catalysis into an in-situ generated acceptor. Furthermore, this protocol showcased the versatility of pro-aromatic DHQZ by acting as a 2-in-1 EDA complex precursor by serving as an EDA donor and a latent acceptor through its by-product in generating carbon-centered radicals compatible with various radical traps to access diverse molecular architectures.