Enantioselective asymmetric Pictet-Spengler reaction catalyzed by diisopinocampheylchloroborane

Abstract

The first example of a reagent-controlled enantioselective Pictet-Spengler reaction is demonstrated. Employing diisopinocampheylchloroborane as a chiral Lewis acid catalyst, the Pictet-Spengler reaction of N(b)-hydroxytryptamine gave the corresponding 2-hydroxy-tetrahydro-β-carbolines up to 90% ee.