Chemistry Letters, Vol.31, No.4, 428-429, 2002
Pictet-Spengler reaction of nitrones and imines catalyzed by Yb(OTf)(3)-TMSCl
The Pictet-Spengler reaction of nitrones and imines prepared from N-hydroxytryptamine and tryptamine gave the corresponding tetrahydro-beta-carbolines in excellent yields in the presence of Yb(OTf)(3)-TMSCl in a mixture of CH2Cl2 and THF.