Gold- and Rhodium-Catalysed Aldol Additions

In 1986 Ito and coworkers reported enantioselective aldol additions of methyl isocyanoacetate to aldehydes mediated by chiral ferrocenyl—gold complexes.^1,2,3 The corresponding trans-configured oxazolines were obtained with an excellent degree of enantioselectivity (Scheme 3.4.1). By hydrolysis the corresponding β-hydroxy-α-amino acids were obtained. This reaction has been extensively studied by Ito^4,5 as well as Togni and coworkers.^{6,7,8,9,10,11,12}