Irradiation wavelength tuned stepwise [2+2] cycloaddition of indolylphenylpropenone derivatives as a platform for light-mechanical energy conversion
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.
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BibTeX
@misc{chen2026irradiation,
title = {{Irradiation wavelength tuned stepwise [2+2] cycloaddition of indolylphenylpropenone derivatives as a platform for light-mechanical energy conversion}},
author = {Chao Chen and Xiqiao Yang and Jingbo Sun and Cheng Liu and Jiangbin Zhong and Kaiqi Ye and Ran Lu},
howpublished = {ChemRxiv},
year = {2026},
month = sep,
doi = {10.26434/chemrxiv.15008250/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008250/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Irradiation wavelength tuned stepwise [2+2] cycloaddition of indolylphenylpropenone derivatives as a platform for light-mechanical energy conversion
AU - Chao Chen
AU - Xiqiao Yang
AU - Jingbo Sun
AU - Cheng Liu
AU - Jiangbin Zhong
AU - Kaiqi Ye
AU - Ran Lu
PY - 2026
DA - 2026/09/03
PB - ChemRxiv
DO - 10.26434/chemrxiv.15008250/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008250/v1
AB - 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.
ER -