Gold selective hydrogenation

Bailie et al. were the first to mention alcohol formation from aldehydes by supported gold-catalyzed selective hydrogenation. The reaction of the formation of crotyl alcohol from crotonaldehyde showed high selectivity (up to 81%) at conversions of 5-10%, with preferential hydrogenation of C=0 rather than the C=C bond [216]. The addition of thiophene promoted this selective hydrogenation. This promotional effect was also observed in similar situations for Cu and Ag, but it was not very common for gold. 

An example of the usefulness of the methodology was the new industrial route to cyclohexanone oxime developed by Corma and Serna, a process which is based on the selective hydrogenation of 1-nitro-l -cyclohexene by gold nanoparticles supported on Ti02 or Fe203 [220]. 

Partly because gold catalysts are active under mild conditions, they have been investigated for other selective oxidation and for selective hydrogenation reactions. Details are given in Sect. 6.2.4. 

Van Koten et al. developed a procedure for the preparation of precious metal catalysts alloyed with, e. g., copper and gold, that can be accommodated easily by the fine-chemieal industry [20-22]. For selective hydrogenation such catalysts... 

Ohyama J, Esaki A, Yamamoto Y, Arai S, Satsuma A (2013) Selective hydrogenation of 2-hydrox5onethyl-5-furfural to 2,5-bis(hydroxymethyl)furan over gold sub-nano clusters RSC Adv 3 1033-1036... 

Zhang X, Guo YC, Zhi CZ, Gao JS, Xu CM. High performance of carbon nanombes confining gold nanoparticles for selective hydrogenation of 1,3-butadiene and cinnamaldehyde. J Catal 2012 292 213-26. 

During the past two decades gold has attracted much attention due to its unique catalytic properties for numerous reactions [116,117]. Therefore, it has been shown that isolated and heterogenized Au"" ions (n = 1 or 3) are highly active in reactions such as the selective hydrogenation of 1,3-butadiene to butenes [ 118], the homocoupling of phenylboronic acid [119], or the selective isomerization of epoxides to allylic alcohols [120]. 

So far, gold dusters have already been used to catalyze some typical reactions, including selective hydrogenation of unsaturated aldehydes and ketones selective oxidation of alkanes, alkenes, and alcohols CO oxidation and organic synthesis. 

---