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)

The steric influence of extended aryl substituents on 2,2′-bis(1,3-oxazoline) 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, 69451 Weinheim, Germany, 2005)