A variation of the Pictet–Spengler reaction via a sequential reduction–cyclization reaction of N-acylcarbamates: synthesis of 1-substituted tetrahydroisoquinoline derivatives
of the Pictet–Spengler reaction for the synthesis of 1-substitutedtetrahydroisoquinoline derivatives has been developed. The reaction employs the reduction of N-acylcarbamates by DIBAL-H followed by simultaneous cyclization mediated by BF3·OEt2. The synthetic potential of this method has been illustrated by the synthesis of the tetrahydroisoquinolinealkaloids, (±)-xylopinine, (±)-laudanosine, (±)-
One-Pot α-Amidosulfone-Mediated Variation of the Pictet-Spengler Tetrahydroisoquinoline Synthesis, Suitable for Amide-Type Substrates
作者:Francisco J. Arroyo、Pilar López-Alvarado、A. Ganesan、J. Carlos Menéndez
DOI:10.1002/ejoc.201402487
日期:2014.9
development of Pictet–Spengler reactions from amide substrates is a challenging problem. We report here that the reaction between amide-type compounds (including carbamates, amides, ureas and diketopiperazines), aldehydes and p-toluenesulfinic acid constitutes an efficient method for the preparation of tetrahydroisoquinolines or pyrazino[2,1-b]isoquinolines. Unlike previously known methods, this one-pot Pictet–Spengler