Highly Enantioselective Bromocyclization of Tryptamines and Its Application in the Synthesis of (−)‐Chimonanthine

These alkaloids have been isolatedfrom diverse sources, including bacteria, fungi, higher plants,marine bryozoans, frogs, and human metabolism. It has beenproposedthat thosealkaloidsare biologically originatedfromtryptamine through an oxidative cyclization reaction. A classof cyclotryptamine alkaloids are dimer, trimer, and higher-ordered oligomers of HPI units connected by the C3’–C3 andC3–C7’ bonds (chimonanthine and hodgkinsine).