Bismuth Triflate−Chiral Bipyridine Complexes as Water-Compatible Chiral Lewis Acids

Catalytic asymmetric hydroxymethylation of silicon enolates with an aqueous formaldehyde solution has been developed using a chiral bismuth complex. This is the first example of highly enantioselective reactions using a chiral bismuth catalyst in aqueous media. In this paper, we have added Bi(OTf)₃−1 complex as a “water-compatible Lewis acid”. Bi(OTf)₃ is unstable in the presence of water but is stabilized by the basic ligand.