Selectivity Control in Nitroaldol (Henry) Reaction by Changing the Basic Anion in a Chiral Copper(II) Complex Based on (<i>S</i>)-2-Aminomethylpyrrolidine and 3,5-Di-<i>tert</i>-butylsalicylaldehyde

Abstract

This article is a continuation of our previous research on the catalytic capability of a chiral copper complex based on commercially available (S)-2-aminomethylpyrrolidine and 3,5-di-tert-butylsalicylaldehyde with various counter-anions in the asymmetric Henry reaction. Our findings indicate that depending on the type of base used, chiral nitroalcohols with yields up to 98% and ee values up to 77%, as well as β-nitrostyrenes with yields up to 88%, can be produced. Additionally, it has been found that the outcome of the reaction and the catalytic properties of copper (II) complexes (S)-Cu1 and (S)-Cu2 are influenced by the structure of the aldehyde used.

Keywords

• henry reaction
• copper complex
• nitroalcohols
• nitrostyrenes
• enantioselectivity