Irradiation wavelength tuned stepwise [2+2] cycloaddition of indolylphenylpropenone derivatives as a platform for light-mechanical energy conversion
Year: 2026
Type: preprint
Abstract: Cyclobutane motifs are widely embedded in natural products, and [2+2] cycloaddition is a facile method to synthesize four-membered rings. In general, controlling the regioselectivity and stereoselectivity of cycloaddition remains a great challenge. Nevertheless, the prearrangement of the reactant molecules in topo-photochemical reaction can place the atoms in the products at specific positions. In this work, the irradiation wavelength-controlled, stepwise photo-induced [2+2] cycloaddition of indolylphenylpropenone derivatives took place in crystals. Under blue light, one kind of monocyclobutane was yielded via the cycloaddition of vinyls, accompanied with single-crystal-to-single-crystal transformation. The monocyclobutane product can be converted into bicyclobutane product by the second-step cycloaddition of carbon-carbon double bonds on five-membered heterocyclic ring in indole upon irradiation with 365 nm light. Such catalyst-free dearomatization of indole via [2+2] cycloaddition has not been reported previously. Driven by [2+2] cycloaddition, the molecular crystals exhibited obvious photomechanical effects.
Source: ChemRxiv
Language: English
Subfield: Physical and Theoretical Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
Award: 动态分子晶体中[2+2]环加成反应驱动的光机械效应研究
OpenAlex ID: W7207856094