Oxidant-free C-H sulfonylation of enamides: Electrochemical synthesis of β-amidovinyl and carbonyl sulfones from sulfonyl hydrazide and enamides

Electrochemically Induced Regio‐ and Stereoselective (E)‐β‐C(sp2)−H Trifluoromethylation and Arylsulfonylation of Enamides

“…To our satisfaction, the standard reaction condition also suitable for the arylsulfonylation of enamides with TsNHNH 2 as the arylsulfonyl source, and the corresponding product 4 h were obtained in 81% yield. And the above 1 H and 13 C nuclear magnetic resonance (NMR) data of the arylsulfonylated enamides products were consistent with the previous literature reports [18e–f] . These results have well proven the E ‐configuration of the arylsulfonylated enamides products.…”

“…Besides trifluoromethyl compounds, organic sulfone compounds are also very important structural motifs widespread in many drug molecules and functional materials [26] . Very recently, the electrochemically induced β‐C( sp 2 )−H arylsulfonylation of enamides had been developed by Zeng group [18e] and Chen group [18f] . To our delight, the standard reaction condition of electrochemically induced ( E )‐β‐C( sp 2 )−H trifluoromethylation of enamides was absolutely suitable for the arylsulfonylation of enamides with ArSO 2 Na as the arylsulfonyl source.…”

The Application of Sulfonyl Hydrazides in Electrosynthesis: A Review of Recent Studies

“…From those experiments, it was found that the sulfonyl hydrazide (95) was activated by an iodide radical which was generated in situ at the anode, and then A similar synthesis of sulfonyl enamines was reported by Chen in 2022 (Scheme 13). 70 The reaction was believed to be triggered by the sulfonyl radical (105), and a key intermediate of the carbon radical (107) was generated by the sulfonyl radical's addition to a C�C double bond. Subsequently, the generated carbon radical (107) was oxidized at the anode, and then a sulfonyl enamine (108) was obtained if the cation was trapped by H 2 O.…”

“…A similar synthesis of sulfonyl enamines was reported by Chen in 2022 ( Scheme 13 ). 70 This sulfonylation of enamines was conducted under a constant current of 10 mA with LiClO 4 as the electrolyte in a mixed solvent of CH 3 CN/H 2 O (10:1, v/v), using a carbon anode and a Pt cathode. Substrates with either electron-donating ( 102a , 102b , 102e , 102f ) or electron-withdrawing groups ( 102c , 102e , 102g – 102i , 102n – 102s ) on the aryl rings all gave corresponding products in medium yields.…”

Electrochemical annulation of 1,2,3-benzotriazinones with alkynes to access isoquinolin-1(2H)-ones

“…12 Although significant progress has been made, the denitrogenation transformation to construct isoquinolin-1(2 H )-ones by electrochemical synthesis remains a challenge in the field. Based on our previous studies 13 and our continued interest in the research of electrocatalysis, 14 we report herein a denitrogenative [4 + 2] annulations of 1,2,3-benzotriazinones with alkynes under electrochemical conditions (Scheme 1c). This method was employed by us to rapidly generate a diverse array of isoquinolin-1(2 H )-ones while avoiding the use of metal catalysts and redox agents.…”