Efficient silver-free gold(I)-catalyzed hydration of alkynes at low catalyst loading

The use of [(IPr)AuOH] as versatile, air- and moisture-stable pre-catalyst permits the in situ generation of the cationic gold(I) species [(IPr)Au]X after reaction with a Brønsted acid. This catalytic system presents as a main advantage the lack of use of a silver salt activator or co-catalyst which is often air-, light- and moisture-sensitive. A general gold(I)-catalyzed procedure using this in situ activation at very low catalyst loading is reported for the hydration of a broad range of internal and terminal alkynes.

Graphical abstractA simple and efficient procedure, compatible with both terminal and internal alkynes, and requiring catalyst loadings as low as 100 ppm is reported. The use of [(IPr)AuOH] 1 as catalyst allowed to perform the hydration of alkynes under silver-free conditions by a simple acid activation.Figure optionsDownload full-size imageDownload as PowerPoint slide