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Updated: Jan 8, 2026

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Published on: July 17, 2020

アミノボラン：エネルギー移動触媒のための合理的に調整された有機光増感剤

Nunzio Matera¹, Alessio Bussolari¹, Michele Mancinelli¹

¹Department of Industrial Chemistry 'Toso Montanari', University of Bologna, via Piero Gobetti, Bologna, 85-40129, Italy.

Angewandte Chemie (International ed. in English)

|December 12, 2025

Abstract:

We report a new class of rationally designed organic photosensitizers based on boron-nitrogen-substituted scaffolds, capable of mediating challenging triplet energy transfer (EnT) reactions under visible-light irradiation. Guided by DFT and TD-DFT calculations, we modulated the twisted intramolecular charge transfer (TICT) character of the excited state through strategic substitution on the carbazole-borane framework, allowing fine-tuning of both absorption and triplet energy levels (E_T = 63-70 kcal mol^-1). The most effective catalyst outperformed traditional Ir- and xanthone-based sensitizers across benchmark EnT reactions, including E/Z isomerizations, [2 + 2] photocycloadditions, and [1,3]-sigmatropic rearrangement. This B-N system enables the sensitization of coumarin-related substrates with E_T ≥ 65 kcal mol^-1, which was previously inaccessible to fully organic EnT photocatalysts. These results establish a new design principle for modular, high-energy triplet sensitizers based on organic aminoborane scaffolds.

キーワード:

アミノボランエネルギー移動（EnT）有機光触媒光化学

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