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Updated: Jul 1, 2025
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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Substrate-controlled [4+1] and [3+2] annulations of ninhydrin-derived Morita-Baylis-Hillman carbonates to access
Kai-Kai Wang1, Yan-Li Li2, Ya-Fei Li1
1School of Pharmacy, Xinxiang University, Xinxiang 453000, P. R. China. chenhlmei@163.com.
Abstract:
The effective and mild [4+1] annulation of ninhydrin-derived MBH carbonates with α,β-unsaturated ketones has been developed, providing a wide range of multisubstituted furans in high yields (up to 90%) with excellent β-regioselectivities. In contrast, the polysubstituted cyclopentenes bearing dispiro-bisindanedione motifs were obtained via classical [3+2] annulations by employing ninhydrin-derived MBH carbonates with 2-arylidene-1,3-indandiones under the same catalytic conditions. Furthermore, the structures of two kinds of cycloadducts were straightforwardly confirmed through X-ray diffraction analysis.
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