A Pd-catalyzed one-pot sequential C–H functionalization strategy was utilized to prepare four lycorine alkaloids and one pseudo-lycorine alkaloid from the common intermediate 4. By switching the followed oxidative conditions of air, DMSO/H2O/I2, and DMSO/O2, based on the Pd(PPh3)4/K2CO3/toluene catalytic system, three key intermediates 12a, 12b, and 12c with different substitution patterns could be