One-Pot Reductive Amination of Aromatic Aldehydes in [Et3NH][HSO4] using Sodium Borohydride and A Mechanistic Investigation using Computational Method

摘要

The reductive amination of aromatic aldehydes and aromatic amines,performed in the Bronsted acidic ionic liquid [Et3NH][HSO4],using sodium borohydride as a reducing agent is reported.In this protocol,the ionic liquid plays a crucial role in efficiently converting aromatic aldehydes to amines in excellent yields,without the formation of side products.In the presence of [Et3NH][HSO4],the imine was generated in situ from the reaction between the aromatic aldehydes and aromatic amines,and underwent smooth reduction with sodium borohydride.This one-pot synthesis is practically simple and sustainable.The catalyst [Et3NH][HSO4] also has a demonstrably wide applicability,in that it can be used with a variety of aromatic aldehydes and aromatic amines substituted by various electron-withdrawing and electron-donating groups.The role of IL [Et3NH][HSO4] in catalytic reductive amination is validated with the help of density functional theory(DFT)-based computational studies.