Concise Total Synthesis of Nauclefine: A Regioselective Rhodium(III)-catalyzed Oxidative C-H Activation Approach

Abstract A concise total synthesis of the plant indole alkaloid natural product nauclefine (1) was accomplished from the commercially available nicotinic acid and the known compound in 6 steps. The synthesis features a regioselective rhodium(III)-catalyzed oxidative C-H activation for the construction of the key naphthyridinone ring. The intramolecular Mitsunobu-type annulation, allylic oxidation and Fischer indolization were used successively to complete the total synthesis of nauclefine (1).