Work

Catellani-Inspired BN-Aromatic Expansion: A Versatile Tool toward π-Extended 1,2-Azaborines with Tunable Photosensitizing Properties

Year: 2026

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide BN-isosterism, the replacement of carbon–carbon units with boron–nitrogen pairs in organic frameworks, offers a powerful means to create novel compounds, yet methods to access larger BN-containing polyaromatic cores remain scarce. Leveraging our recently developed multigram-scale synthesis of BN-naphthalene, we now combine it with a Catellani-type arene extension (Pd(OAc) 2 /P(2-furyl) 3, norbornene) to rapidly access diverse extended BN-embedded polyaromatic cores. This strategy delivers BN-embedded benzo[ c ]phenanthridines and curved 8- and 7-membered ring-fused derivatives, as well as BN-embedded benzofluorenones in both normal and inverse BN-vector orientations. Importantly, the ability to access both directional BN isomers, in addition to the parent C═C core, provides a rare opportunity to directly interrogate the effect of the presence and sense of the BN moiety. Most notably, light-induced singlet oxygen ( 1 O 2 ) generation promoted by the benzofluorenone core shows a more than 10-fold enhancement in the “boron-up” BN isostere, while dropping to negligible levels upon inversion of the BN unit. This work thus offers a blueprint for experimental electronic tuning of optically responsive organic materials through BN-mapping.

Source: Journal of the American Chemical Society

DOI: 10.1021/jacs.5c19389