Cover Picture: Iron‐ and Bismuth‐Catalyzed Asymmetric Mukaiyama Aldol Reactions in Aqueous Media (Chem. Asian J. 12/2013)

The Mukaiyama aldol reaction of a silyl enol ether with an aldehyde mediated by TiCl 4 was first published in 1973. After that, tremendous efforts have been made to improve this potentially versatile protocol, leading to remarkable advances of this reaction. In their Full Paper on page 3051 ff., Shū Kobayashi et al. report on asymmetric Mukaiyama aldol reactions of silicon enolates with aldehydes catalyzed by chiral Fe II and Bi III complexes. The reactions proceeded in the presence of water at 0 °C to afford the desired aldol products in high yields with high diastereo‐ and enantioselectivities. The assumed catalytic cycle and transition states indicated important roles of water in these efficient asymmetric Mukaiyama aldol reactions.