Overview of Homogeneous Catalysis by Gold

The gold compounds were amongst the most active catalysts but it is now known that other Lewis acid catalysts such as ferric chloride are superior for this reaction. 

A significant advance was made in 2001 when the oxidation of sulfides to sulfoxides was achieved using HAuC /AgNOs in acetonitrile as catalyst under 1 atm oxygen or air 5 

This catalyst had activity orders of magnitude higher than the previously used Ru11 or CeIV complexes, and this was a clear indication that sulfur does not poison the catalytic activity of gold. There is in fact clear evidence that sulfur can be a promoter for catalysis by gold.6 

The oxidative carbonylation of amines to formamides was also reported in 2001 in up to 94% yield using Ph3PAuTCl as catalyst and oxygen as oxidant in methanol 7 

The use of gold as a catalyst is desirable when it has a similar activity to that for a more expensive catalyst, or when it shows a higher activity or a higher selectivity than less expensive catalysts, and also when a completely new chemical transformation is possible using the gold catalyst. We will focus on examples of these three types in the following sections. 

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