Reusable catalysts for the asymmetric Diels-Alder reaction.
A new method for recycling chiral bis(oxazoline)-copper complexes is described based on the formation of charge-transfer complexes, their subsequent precipitation, and reuse after addition of new substrates. The conditions to perform this procedure were optimized in the presence of three bis(oxazoline)-based ligands. When associated with copper salts, these ligands efficiently catalyzed the Diels-Alder reaction between cyclopentadiene and alpha,beta-unsaturated acyloxazolidinones. These catalysts were successfully recycled up to ten times while maintaining their high activities and enantioselectivities.
Chollet
Guillaume
G
Equipe de Catalyse Moléculaire, ICMMO, UMR 8182, Université Paris-Sud, 91405 Orsay, France.
Guillerez
Marie-George
MG
Schulz
Emmanuelle
E
D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D003517:Cyclopentanes / Q000737:chemistry*; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010080:Oxazoles / Q000138:chemical synthesis / Q000737:chemistry*; D023303:Oxazolidinones / Q000138:chemical synthesis* / Q000737:chemistry*; D013237:Stereoisomerism
D003517:Cyclopentanes; D008024:Ligands; D009942:Organometallic Compounds; D010080:Oxazoles; D023303:Oxazolidinones; D003300:Copper