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Updated: May 8, 2026
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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Electrochemically Driven, pKa-Controlled Regioselective Selenocyclization: Synthesis of Isocoumarin-1-imines with
Renxiu Zhang1, Yi Zhou1, Zhanzhou Wei1
1Department of Chemistry, China Agricultural University, Beijing 100193, P. R. China.
Abstract:
This study presents an electrochemical strategy that leverages the pKa of N-substituents to achieve precise regiocontrol in the selenocyclization of 2-alkynylbenzamides, providing efficient access to 4-selenyl isocoumarin-1-imines. This method successfully overcomes the longstanding selectivity challenges between competitive O/N-attack cyclization pathways. Crucially, the structure of the O-cyclized product was unambiguously confirmed by X-ray crystallographic analysis. Density functional theory (DFT) calculations further rationalize the observed high regioselectivity, revealing a significantly lower energy barrier for the O-attack pathway. The gram-scale synthesis and preliminary bioassays for fungicidal activity demonstrate the potential applications of this method.
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