Diradical

Physics

Computational chemistry

Catalysis

Organic chemistry

Excited state

Nuclear physics

Chemistry

Indole test

Reactive intermediate

Combinatorial chemistry

Hydrogen atom

Cycloaddition

Indoline

Alkyl

Molecule

Singlet state

Stereochemistry

Photochemistry

ACS Catalysis

Visible-light-induced dearomatization reaction via energy-transfer mechanism is an emerging strategy for the synthesis of highly strained polycyclic molecules. Transient, high-energy diradical species are typically involved in this type of reaction as key intermediates. Herein, we report the visible-light-induced divergent dearomatization of indole-tethered O-methyl oximes, in which the reactions of the open-shelled singlet diradical intermediates toward competitive [2 + 2] cycloaddition or 1,5-hydrogen atom transfer can be achieved with exclusive selectivity. The mechanism has been well supported by a series of experimental and computational investigations. The dearomatization reactions allow the facile synthesis of structurally appealing indoline-fused azetidines and related polycyclic molecules with high efficiency.

Visible-Light-Induced Dearomatization via [2+2] Cycloaddition or 1,5-Hydrogen Atom Transfer: Divergent Reaction Pathways of Transient Diradicals