Cu-catalyzed asymmetric Henry reaction promoted by chiral camphor Schiff bases

• Cu-camphor Schiff base complexes were firstly investigated as catalysts in asymmetric Henry reaction.
• The diastereoisomeric Schiff bases 5a and 5a' were successfully isolated and gave completely converse absolute configuration of catalyzed products when it used in the Henry reaction as ligand, respectively.
• The chiral camphor Schiff base 5a, together with CuCl, showed high efficiency in catalyzed asymmetric Henry reactions between various aldehydes and nitromethane.

Five novel chiral camphor Schiff bases have been synthesized and utilized as ligands in asymmetric Henry reaction between nitromethane and aldehydes. The diastereoisomeric Schiff bases 5a and 5a' were separated successfully and gave completely different absolute configurations in the reaction. The reactions were carried out with CuCl-Schiff base 5a complex under mild condition with good yields and enantioselectivities. This is the first time that camphor-derivated Schiff bases were used as ligands in asymmetric Henry reaction.

Figure optionsDownload high-quality image (87 K)Download as PowerPoint slide