Effects of extended aryl-substituted bisoxazoline ligands in asymmetric synthesis - Efficient synthesis and application of 4,4′-bis(1-naphthyl)-, 4,4′-bis(2-naphthyl)- and 4,4′-bis(9-anthryl)-2,2′- isopropylidenebis(1,3-oxazolines)

Abstract

The steric influence of extended aryl substituents on 2,2′-bis(1,3- oxazollne) ligands was investigated in a series of asymmetric catalytic reactions such as Mukaiyama aldol and Michael reactions, hetero-Diels-Alder processes, and allylic alkylation reactions. 4,4′-(2-Naphthyl)- and 4,4′-(9-anthryl)-substituted isopropylidene-bridged 2,2′-bis(1,3- oxazolines) were synthesized and their enantioselective and catalytic properties in combination with different metals evaluated. © Wiley-VCH Verlag GmbH & Co. KGaA, 2005.