An efficient radical addition/elimination reaction that enables selective incorporation of alkenyl, alkynyl and allyl functional groups into the C(sp³)–H bond under green reaction conditions is developed. The process is based on the catalytic formation of α-alkoxyl/α-amidyl radicals via the homolytic activation of the C(sp³)–H bond of ethers/amides with a catalytic amount of diarylketone in the presence of a household fluorescent light bulb. This simple reaction protocol features good functional group tolerance, scalability, convenient reagents and operating systems. Synthetic application of the method has been demonstrated via the preparation of natural products and different valuable synthones.