Physics

Pathology

Nanotechnology

Organic chemistry

Combinatorial chemistry

Reactivity (psychology)

Ring (chemistry)

Rational design

Stereochemistry

Catalysis

Computational chemistry

Excited state

Indole test

Nuclear physics

Chemistry

Materials science

Alternative medicine

Bicyclic molecule

Cycloaddition

Cyclobutane

Intramolecular force

Medicine

Photochemistry

Journal of the American Chemical Society

An intramolecular dearomatization of indole derivatives based on visible-light-promoted [2+2] cycloaddition was achieved via energy transfer mechanism. The highly strained cyclobutane-fused angular tetracyclic spiroindolines, which were typically unattainable under thermal conditions, could be directly accessed in high yields (up to 99%) with excellent diastereoselectivity (>20:1 dr) under mild conditions. The method was also compatible with diverse functional groups and amenable to flexible transformations. In addition, DFT calculations provided guidance on the rational design of substrates and deep understanding of the reaction pathways. This process constituted a rare example of indole functionalization by exploiting visible-light-induced reactivity at the excited states.

Synthesis of Cyclobutane-Fused Angular Tetracyclic Spiroindolines via Visible-Light-Promoted Intramolecular Dearomatization of Indole Derivatives