Bioorthogonal reactions can take place in biological environments without interfering with biochemical processes. In this study, Pd(PPh3)2Cl2 was used as a bioorthogonal catalyst to in situ transform the stable N-heterocyclic carbene (NHC)-gold(I)-alkyne complex 5 to its active species which can effectively inhibit thioredoxin reductase (TrxR) and exhibit significant anticancer bioactivity in hepatocellular carcinoma (HCC).