New Proline–Oxazoline Ligands and Their Application in the Asymmetric Nozaki–Hiyama–Kishi Reaction
作者:Gráinne C. Hargaden、Helge Müller-Bunz、Patrick J. Guiry
DOI:10.1002/ejoc.200700227
日期:2007.9
of a newligand class incorporating an oxazoline ring linked by an amide bond to a chiral protected proline unit were prepared in a high-yielding four-step synthesis from readily available chiral amino alcohols and N-protected proline. The ligands were applied in the enantioselective Nozaki–Hiyama–Kishi allylation of benzaldehyde and gave enantioselectivities of up to 57 %. Diastereomeric ligand pairs
Oxazoline-Substituted Prolinamide-Based Organocatalysts for the Direct Intermolecular Aldol Reaction between Cyclohexanone and Aromatic Aldehydes
作者:Simon Doherty、Julian G. Knight、Amy McRae、Ross W. Harrington、William Clegg
DOI:10.1002/ejoc.200700922
日期:2008.4
Oxazoline-substituted prolinamides catalyse the direct asymmetric aldol reaction between cyclohexanone and a range of aldehydes to give excellent conversions and enantioselectivities up to 84 % under optimum conditions. Reactions were highly substrate-specific with electron-deficient aldehydes giving the highest yields and ee values. The absolute configuration of the 4-chlorobenzaldehyde-derived product