Application of a recyclable pseudoephedrine resin in asymmetric alkylations on solid phase.
A pseudoephedrine resin has been successfully employed in asymmetric alkylations on solid phase. Immobilized pseudoephedrine amides are conveniently prepared by the one-step attachment of pseudoephedrine to Merrifield resin through the hydroxyl group and subsequent acylation on nitrogen. Deprotonation and alkylation of the resin-bound amides proceeds smoothly. Ketones and alcohols are cleaved from the resin in high enantiomeric excess and moderate to good overall yield. The parallel, asymmetric solid-phase synthesis of a small library of chiral ketones and alcohols has been carried out to illustrate the utility of the approach. Finally, the pseudoephedrine resin can be conveniently recycled and utilized with no significant loss in the yield or enantiomeric excess of the products.
Hutchison
Panee C
PC
Department of Chemistry, The Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK.
Heightman
Tom D
TD
Procter
David J
DJ
D000438:Alcohols / Q000138:chemical synthesis; D000478:Alkylation; D000577:Amides / Q000737:chemistry; D004809:Ephedrine / Q000737:chemistry*; D017743:Equipment Reuse; D007659:Ketones / Q000138:chemical synthesis; D011137:Polystyrenes / Q000737:chemistry*; D013237:Stereoisomerism
D000438:Alcohols; D000577:Amides; D007659:Ketones; C095039:Merrifield resin; D011137:Polystyrenes; D004809:Ephedrine