Access to Diverse Seleno-spirocyclohexadienones via Ag(II)- Catalyzed Selenylative ipso-Annulation with Se and Boronic Acids

An efficient and straightforward synthesis of diversified seleno-azaspiro-2,5-cyclohexadienones from N-(4-me-thoxy aryl)propiolamides using elemental selenium and boronic acids has been demonstrated. The reaction proceeds through silver-catalyzed oxidative dearomatization in the presence of potassium persulfate (K2S2O8) as the oxidant. Further, this approach was extended to N-(4-methoxy aryl)propiolates and biaryl ynones to access the corresponding selenylated oxospiro-2,5-cyclohexadie-nones and spiro[5,5]trienones, respectively. The present three-component method offers the diverse substitutions on selenium involving two C-Se and one C-C bond formations.

Automated summary

An efficient and straightforward method for the synthesis of diversified seleno-azaspiro-2,5-cyclohexadienones from N-(4-methoxy aryl)propiolamides using elemental selenium and boronic acids has been demonstrated. This method can also be extended to N-(4-methoxy aryl)propiolates and biaryl ynones to access the corresponding selenylated oxospiro-2,5-cyclohexadienones and spiro[5,5]trienones, respectively.