posted on 2021-08-04, 20:43authored byYong Wu, Li Zeng, Haoran Li, Yue Cao, Jingcheng Hu, Minghao Xu, Renyi Shi, Hong Yi, Aiwen Lei
Oxidative
carbonylation using carbon monoxide has evolved as an
attractive tool to valuable carbonyl-containing compounds, while mixing
CO with a stoichiometric amount of a chemical oxidant especially oxygen
is hazardous and limits its application in scale-up synthesis. By
employing anodic oxidation, we developed an electrochemical palladium-catalyzed
oxidative carbonylation of arylhydrazines with alkynes, which is regarded
as an alternative supplement of the carbonylative Sonogashira reaction.
Combining an undivided cell with constant current mode, oxygen-free
conditions avoids the explosion hazard of CO. A diversity of ynones
are efficiently obtained using accessible arylhydrazines and alkynes
under copper-free conditions. A possible mechanism of the electrochemical
Pd(0)/Pd(II) cycle is rationalized based upon cyclic voltammetry,
kinetic studies, and intermediates experiments.