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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Visible-Light-Driven [3 + 2]/[4 + 2] Annulation Reactions of Alkenes with N-Aminopyridinium Salts
Yu-Zhao Wang1, Peng-Yu Liang1, Hong-Chao Liu1
1State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China.
Abstract:
The annulation reactions of benzoamidyl radicals with alkenes were realized under visible light irradiation with fac-Ir(ppy)3 as catalyst and N-aminopyridinium salts as benzoamidyl radical precursors. The reaction can deliver two distinct types of products: in the case of vinyl arenes, [3 + 2] annulation product dihydrooxazoles were yielded exclusively; when alkyl-substituted alkenes were used, on the other hand, it afforded [4 + 2] annulation product dihydroisoquinolinones. Factors determining the reaction consequence were elucidated by DFT calculations.
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