Copper-catalyzed oxidative ipso-carboalkylation of activated alkynes with ethers leading to 3-etherified azaspiro[4.5]trienones

Cu-catalyzed synthesis of 3-etherified azaspiro[4.5]trienones from N-arylpropiolamides and ethers is presented using TBHP oxidant. This is achieved through C(sp3)–H functionalization, ipso-carbocyclization and dearomatization, and this method represents a new example of alkyne oxidative 1,2-difunctionalization with an ipso-aromatic carbon and a C(sp3)–H bond by simultaneously forming two new carbon–carbon bonds.