Enantioselection using modified zeolite catalysts

✍ Scribed by Saskia Feast; Donald Bethell; Philip C. Bulman Page; Frank King; Colin H. Rochester; M.Rafiq H. Siddiqui; David J. Willock; Graham J. Hutchings

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 392 KB
• Volume: 107
• Category: Article
• ISSN: 1381-1169
• DOI: 10.1016/1381-1169(95)00223-5

✦ Synopsis

The proton form of zeolite Y was modified with R-1,3-dithiane-1-oxide at a loading of one molecule per supercage to create a chiral acid catalyst. The enantiomeric discrimination of this catalyst was demonstrated using the dehydration of the separate enantiomers of butan-2-ol and over the temperature range investigated the S-enantiomer was always more reactive. This catalyst system was then studied using computational simulation methods. The lowest energy structures for the enantiomers of butan-2ol docked into a model of the modified zeolite were calculated and it was found that the binding energy for the S-enantiomer is 64.7 kJ mol-~ and that for the R-enantiomer is 48.3 kJ mol ~. This difference in the adsorption of the two enantiomers is considered to be the origin of the enhanced reactivity of the S-enantiomer.