A metal-free cross-dehydrogenative coupling of N -carbamoyl tetrahydroisoquinoline by sodium persulfate

A metal-free cross-dehydrogenative coupling of N-carbamoyl tetrahydroisoquinoline with a variety of CH nucleophiles mediated by Na2S2O8 is developed. The reaction proceeds smoothly to give the coupled product in up to 83% yields. The nucleophile scope is broad, including simple ketones, aldehydes, and aryl rings. The carbamoyl protecting group can be readily removed under mild condition. The use of Na2S2O8 as the sole reagent for the CDC reaction is attractive based on economical and environmental factors.