Electrochemically Enabled Dehydrogenative Phosphorothiolation of 2H-Indazoles under Electrolyte-Free Conditions

We have developed an electrochemical method for phosphorothiolation of 2H-indazoles using S-hydrogen phosphorothioates via cross dehydrogenative coupling reaction under metal-free and electrolyte-free conditions. This protocol is compatible with electron donating groups like -Me, -OMe, halogen and elctron withdrawing groups such as -COOEt, affording respective indazolyl phosphorothioates in 62%-91% yields. Comprehensive mechanistic studies indicate that the reaction proceeds through a radical pathway.