Iodine‐Mediated Domino C(sp²)–H Sulfonylation/Annulation of Enaminones and Sulfonyl Hydrazines for the Synthesis of 3‐Sulfonyl Chromones

Abstract

Radical C(sp2)–H sulfonylation and C(sp2)–N bond oxygenation enabling the chemoselective synthesis of 3‐sulfonyl chromones by using enaminones and sulfonyl hydrazines were accomplished. The domino reactions ran well by using molecular iodine without the assistance of any strong oxidant such as a peroxide or a hypervalent metal salt.

Alkyl Propiolates Participated [3+2] Annulation for the Switchable Synthesis of 1,5‐ and 1,4‐Disubstituted 1,2,3‐Triazoles Containing Ester Side Chain

“…On the other hand, in the reaction with tosyl azide, the formation of the NH ‐enaminoester 8 enables analogous transformations in previously reported [3+2] cycloaddition of NH ‐enaminone to provide the 1,4‐disubstituted 1,2,3‐triazoles 6 a . It is notable that part of the in situ formed HI can be regenerated to molecular iodine under air atmosphere with heating, and thus promotes the completion of the reaction …”

Sulfonyl Hydrazides in Organic Synthesis: A Review of Recent Studies

“…20‐2). The Wan group developed a iodine‐mediated sulfonylation‐annulation of enaminones, leding to 3‐sulfonyl chromones without the assistance of strong oxidant (Eq. 20‐3).…”

Gas phase reaction between chromones and solvent in an electrospray ionization source

“…Water was purified by Milli‐Q purification system (Millipore, Billerica, Massachusetts). 3‐Sulfenyl chromone derivates (compounds 1–10 ) were kindly donated by Prof. Wan from Jiangxi Normal University . Chromone‐3‐carboxylic acid, flavone (compound 13 ), and aniline were obtained from J&K (Beijing, China).…”