Enantioselective Synthesis: Steric and electronic effects of the substrates upon stereoselectivity in the gold(I)‐catalyzed aldol reaction with chiral ferrocenylamine ligands, preliminary communication

Enantioselectivity in the gold(I)‐catalyzed aldol reaction with chiral ferrocenylamine ligands is strongly dependent upon both the steric and electronic effects of the substrates. In the reaction of pyridine‐2‐, 3‐, and 4‐carbaldehydes with ethyl 2‐isocyanoacetate, surprisingly and significantly different enantioselectivities were observed in the formation of the cis ‐ and trans ‐dihydro‐oxazoles that must be due to electronic rather than steric effects. The first example of double stereodifferentiation in the gold(l)‐catalyzed aldol reaction is reported.