A copper-catalyzed insertion of sulfur dioxide via radical coupling. Issue 21 (19th February 2020)

• Record Type: Journal Article
• Authors: Zhang, Jun; Yang, Min; Liu, Jin-Biao; He, Fu-Sheng; Wu, Jie
• Is Part Of: Chemical communications. Volume 56:Issue 21(2020)
• Page Start: 3225
• Page End: 3228
• Publication Date: 2020-02-19
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1039/d0cc00375a
• Languages: English
• ISSNs: 1359-7345

Abstract

Abstract : A copper-catalyzed reaction of O -acyl oximes, DABCO·(SO2 )2, and 2 H -azirines is developed under mild conditions, leading to diverse tetrasubstituted β-sulfonyl N -unprotected enamines with excellent stereoselectivity and regioselectivity. Abstract : A copper-catalyzed three-component reaction of O -acyl oximes, DABCO·(SO2 )2, and 2 H -azirines under mild conditions has been achieved. This protocol provides an efficient route for the construction of various tetrasubstituted β-sulfonyl N -unprotected enamines in moderate to good yields with excellent stereoselectivity and regioselectivity. Notably, this method represents a rare example of 2 H -azirines as useful synthons for β-functionalized N -unprotected enamines. Preliminary mechanistic studies indicate that the reaction proceeds through coupling of a sulfonyl radical and α-carbon radical via copper-catalyzed ring-opening C–C bond cleavage of O -acyl oxime and C–N bond cleavage of 2 H -azirine with the insertion of sulfur dioxide.