Chiral environments at alkaloid-modified platinum surfaces

Propyne hydrogenation over alumina-supported palladium and platinum catalysts

“…Ziegler et al [34] and Liu et al [35] have examined the performance of palladium based catalysts for propyne hydrogenation in membrane reactors. Wells and co-workers have recently demonstrated the importance of modified metal surfaces for enantioselective hydrogenation reactions by showing that propyne adsorption can favourably affect enantiomeric excesses [36][37][38].…”

Chiral resolution of R and S 1-phenylethanol on glassy carbon electrodes

“…The modified electrode surface then probably provides a chiral surface for proton abstraction. The fact that Pt surfaces can be rendered enantioselective by the adsorption of alkaloids is well established [15][16][17][18]. Potential dependent, site-selective adsorption of organic compounds on GC WE has been reported by Weisshaar and Porter [18].…”

Non‐Zeolitic Standard Catalysts

“…The effects on its catalytic properties of the addition of silver, titania and alumina [14], chlorine, oxygen, sulfur, ammonia, and carbon monoxide have all been examined [7], but of particular interest is its extensive use in studies of enantioselective hydrogenation [16][17][18][19][20][21][22][23][24][25], where its long-term stability has been an asset over some 20 years of experimentation. Its metallic function has always maintained the same dispersion and other particle characteristics, while being modified in a number of different ways to impart enantioselectivity.…”

“…Its metallic function has always maintained the same dispersion and other particle characteristics, while being modified in a number of different ways to impart enantioselectivity. Although the Pt particles have no nett chiral quality of themselves, chiral environments can be created at the Pt surface by the adsorption of cinchona, morphine, and strychnos alkaloids [20,22,25]; that is, sites having a chiral quality are created adjacent to these adsorbed alkaloid molecules. Selective enantioface adsorption of pro-chiral molecules may occur at these sites providing, on hydrogenation, preferential formation of one enantiomer of the product.…”