Tandem CuI – Zinc dust as a sustainable catalyst for the preparation of propargylamine derivatives via an A3 coupling reaction, under neat conditions

Abstract

The cooperative activity of two proximal metal ions is well-known to exhibit highly efficient and synergistic catalytic activities in living organisms. Owing to this knowledge, tandem Cu–Zn systems have been widely used to catalyze a diversity of chemical transformations. This report describes the use of CuI and zinc dust as a sustainable tandem catalyst for the preparation of propargylamines via a three-component coupling reaction under neat conditions. This reaction proceeds at low temperature, and produces good yields with a number of aliphatic and aromatic aldehydes. The reactivity of a number of amines and alkynes has also been explored under these reaction conditions, resulting in 33 fully characterized compounds prepared in the process. Among the ketones tested during this study, only cyclohexanone was able to produce the expected product in a decent yield. The catalytic system reported here represents one of the sustainable approaches to the preparation of propargylamines, as it involves the use of naturally abundant metals as a tandem catalyst, at a low temperature and under neat conditions.