Abstract
New chiral Cu (II) complexes 1–6 were generated in situ by the interaction of different sources of copper(II) salts with chiral monomeric and dimeric macrocyclic [H4]salen ligands derived from (1R,2R)-(−)-1,2-diaminocyclohexane and (1R,2R)-(−)-1,2-diphenyl-1,2-diaminoethane with trigol-bis(aldehyde). A variety of aldehydes were found to be suitable substrates with nitromethane in the presence of chiral macrocyclic [H4]salen complexes 1–6 for asymmetric nitroaldol reaction at RT. Excellent yields (98% with respect to the aldehyde) of β-nitroalcohols with high enantioselectivity (ee, ∼99%) were achieved in the case of 2-fluorobenzaldehyde in ∼20 h with the use of chiral mononuclear and dinuclear macrocyclic Cu(II) salen complexes 2 and 5. Both chiral mononuclear and dinuclear macrocyclic [H4]salen catalysts 2- and 5-mediated nitroaldol processes are recyclable (up to eight cycles with no significant loss in its performance).
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
