Chiral Macrocyclic Ytterbium Complex Catalysis in Aqueous Media

Significance

Chiral lanthanide complexes are now being investigated as catalysts for a variety of reductions and C-C bond-forming reactions (M. Shibasaki, N. Yoshikawa Chem. Rev. 2002, 102, 2187). However, non-aqueous reaction conditions are necessary due to the hydrolytic instability of many of these complexes. In the present work the authors report that chiral ytterbium complex 1 efficiently catalyzes the Henry reaction in aqueous media. Various pyruvate salts were utilized to give nitro-aldol products in moderate to good yields and enantioselectivities.