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