An efficient silver-assisted oxidative coupling of simple ethers with tert-butyl isocyanide was realized in the presence of DDQ. The direct synthesis of high density functional β-carbonyl α-iminonitriles was achieved in a single step with high yields through the synergetic cascade isocyanide insertion into C(sp3)-H bond, where the isocyanide was used as crucial "CN" and "C═N" sources and the tert-butoxyl group acted as the carbonyl source. Diverse reactivity of β-carbonyl α-iminonitriles has been demonstrated.