Novel chiral Tetraazacalix[4]arene[2]triazine-based derivatives as catalysts: enantioselective Michael reaction of nitroolefins and diketones.

A novel derivatives of tetraazacalix[4]arene[2]triazine-based catalysts for enantioselective Michael addition reactions of nitroolefins and diketones were presented. Chiral moieties were connected to the heteroatom-bridged calix-triazin scaffold by reactions of (S)- or (R)-(+)-1-(1-Naphthyl)ethylamine with tetraazacalix[4]arene[2]triazine. To utilize the catalytic activity of the chiral catalysts, diketones reacted with a wide variety of trans-β-nitrostyrenes in Toluene, respectively, obtaining the Michael products in excellent yields and enantiomeric excesses (up to 96% yield and 99% ee). [ABSTRACT FROM AUTHOR]