Hydrogen‐Bonding Catalysis of Tetraalkylammonium Salts in an Aza‐Diels–Alder Reaction

Abstract

A piperidine-derived tetraalkylammonium salt with a non-coordinating counteranion worked as an effective hydrogen-bonding catalyst in an aza-Diels-Alder reaction of imines and a Danishefsky diene. The hydrogen-bonding interaction between the ammonium salt and an imine was observed as part of a (1) H NMR titration study.