Photoinduced, strain-promoted cycloadditions of trans-cycloheptenones and azides. Issue 20 (2nd October 2020)

• Record Type: Journal Article
• Authors: Yang, Hongzhi; Zeng, Tianying; Xi, Shuang; Hu, Shengkun; Wu, Yunfei; Tang, Yefeng
• Is Part Of: Green chemistry. Volume 22:Issue 20(2020)
• Page Start: 7023
• Page End: 7030
• Publication Date: 2020-10-02
• Subjects: Environmental chemistry -- Industrial applications -- Periodicals; Environmental management -- Periodicals; 660
• DOI: 10.1039/d0gc02347g
• Languages: English
• ISSNs: 1463-9262

Abstract

Abstract : Metal-free cycloadditions of cycloheptenones with azides have been developed, hinging on a photoisomerization/1, 3-dipolar cycloaddition/aerobic oxidation reaction sequence. Abstract : An unprecedented photoinduced azide–alkene cycloaddition has been developed, the key elements of which include the photoisomerization of cis -cycloheptenone to trans -cycloheptenone, strain-promoted 1, 3-dipolar cycloaddition of trans -cycloheptenone with azide, and aerobic oxidative aromatization of the resulting 1, 2, 3-triazoline. The newly developed photoclick reactions display several appealing features including high overall efficiency, broad substrate scope, environmentally benign conditions, and operational simplicity, which provide an enabling tool for accessing structurally diverse 1, 2, 3-triazoles. In addition, the photoisomerization–cycloaddition strategy could also be extended to the 1, 3-dipolar cycloadditions of trans -cyclooctenone with azide and trans -cycloheptenone with nitrile oxide. More appealingly, the title reaction has been successfully applied as a bioconjugation tool for in vitro protein labeling.