Tilt the Molecule and Change the Chemistry: Mechanism of S-Promoted Chemoselective Catalytic Hydrogenation of Crotonaldehyde on Cu(111)

✍ Scribed by May E. Chiu; David J. Watson; Georgios Kyriakou; Mintcho S. Tikhov; Richard M. Lambert

• Book ID: 101561057
• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 229 KB
• Volume: 45
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/anie.200603408

✦ Synopsis

The chemoselective hydrogenation of a,b-unsaturated carbonyl compounds to form unsaturated alcohols is challenging, fundamentally interesting, and important both in the research laboratory and on a technical scale, as these materials are valuable and versatile intermediates in the production of fine chemicals and pharmaceuticals. Thermodynamics favors hydrogenation of the C=C bond to form the (unwanted) saturated aldehyde or ketone as shown in Scheme 1, which refers to the particular case of crotonaldehyde. Thus chemoselective C = O hydrogenation is a demanding process that requires the manipulation of kinetic effects by means of a suitable catalyst.

A variety of supported metal-particle catalysts (including Pt, Pd, Cu, Ag, Au, Ir, and Os) that exhibit a wide range of chemoselectivity have been investigated for this purpose, [1] though very little has emerged in terms of fundamental understanding. Theoretical studies [2] suggest that the adsorption geometry of the reactant molecule may be a key Scheme 1. Possible hydrogenation products of crotonaldehyde.