Enantioselective Palladium‐Catalyzed Decarboxylative Allylation of Carbazolones: Total Synthesis of (−)‐Aspidospermidine and (+)‐Kopsihainanine A

Functionalized chiral carbazolones with α-quaternary carbon centers are formed through the ligand-controlled Pd-catalyzed enantioselective decarboxylative allylic alkylation of carbazolones (see scheme). This catalytic asymmetric reaction was employed as the key step in the total synthesis of aspidospermidine and (+)-kopsihainanine A.