Abstract

Propargylamines are versatile synthetic precursors that are widely used in the synthesis of pharmaceuticals and other bioactive molecules.1 One convenient method to access these molecules is metal-catalysed coupling of aldehyde, alkyne and amine (A3 coupling), which was first developed by Li and co-workers.2 Over the last two decades, this catalytic coupling reaction has been developed to use a diverse array of metal salts and organometallic complexes.3 As a result, it has been widely used in the synthesis of natural products and other bioactive compounds.3 Here we report the first time synthesis of a gold (I) catalyst using the water-soluble vitamin B1 or thiamine as an NHC ligand and its use as a catalyst of the A3 coupling. Remarkably, the resulting NHC-gold (I) catalyst is water-soluble, resistant to oxygen and highly efficient in the catalysis of the coupling reaction in open air, at low temperature and in water or under solvent-free conditions (Scheme 1). 

Scheme 1. NHC-gold(I) catalyzed an efficient synthesis of propargylamine

Acknowledgement

This work was supported by GRF16301922 from the Research Grants Council of the Government of Hong Kong Special Administrate Region.

Reference:

1. Arshadi, S.; Vessally, E.; Edjlali, L.; Hosseinzadeh-Khanmiri, R.; Ghorbani-Kalhor, R. J. Org. Chem. 2017, 13, 625.
2. C.-J. Li, C. Wei, Chem. Commun., 2002, 268.
3. Vsevolod A. Peshkov, Olga P. Pereshivko, Erik V. Chem. Soc. Rev., 2012, 41, 3790.