Bismuth Triflate-Chiral Bipyridine Complexes as Water-Compatible Chiral Lewis Acids
Shu Kobayashi,* Tsuyoshi Ogino, Haruka Shimizu, Shunpei Ishikawa, Tomoaki Hamada and Kei Manabe
*Graduate School of Pharmaceutical Sciences, The University of Tokyo, The HFRE Division, ERATO, Japan Science and Technology Agency (JST), Hongo, Bunkyo-ku, Tokyo 113-0033, Japan, Email: skobayasmol.f.u-tokyo.ac.jp
S. Kobayashi, T. Ogino, H. Shimizu, S. Ishikawa, T. Hamada, K. Manabe, Org. Lett., 2005, 7, 4729-4731.
DOI: 10.1021/ol051965w (free Supporting Information)
Highly enantioselective hydroxymethylation of silicon enolates with an aqueous formaldehyde solution has been developed using a chiral bismuth complex as a Lewis acid. Bi(OTf)3 is unstable in the presence of water but is stabilized by the basic ligand.
see article for more examples
M. Kokubo, S. Kobayashi, Synlett, 2008, 1562-1564.