Ligand- and Acid-Free Gold(I) Chloride Catalyzed Hydration of Terminal Alkynes

Abstract

Our work shows that simple alkynes can be hydrated by the AuCl/MeOH catalyst system to afford the corresponding methyl ketones in moderate to high yields without any additive, ligand, or acid promoter. This methodology is simpler, milder, and operationally easier than those reported before. The reaction media significantly affects the reaction, and methanol is found to be the best solvent. Both aliphatic and aromatic terminal alkynes were able to undergo hydration, affording moderate to excellent yields under the reaction conditions used in the present work, and excellent functional-group tolerance was also observed. A plausible mechanism for the hydration reaction was proposed.

Key words

hydration - alkynes - ketones - gold - homogeneous catalysis

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