A simple, practical and eco-friendly visible light-induced alkylation of N-sulfonyl ketamine under metal-,additive-, external photocatalyst-free conditions was developed. This photocatalytic method utilized low cost and abundant alkanes as the atom economy alkyl sources with H2O2 as the environmentally beneficial oxidant, allowing for the efficient construction of diverse valuable 4-alkylated sulfonyl ketamines.The N-sulfonyl ketamine played a dual role of react...