Binuclear Cu(II) chiral complexes: synthesis, characterization and application in enantioselective nitroaldol (Henry) reaction. (25th November 2015)

• Record Type: Journal Article
• Authors: Chinnaraja, E.; Arunachalam, R.; Choudhary, Manoj K.; Kureshy, R. I.; Subramanian, P. S.
• Is Part Of: Applied organometallic chemistry. Volume 30:Number 2(2016:Feb.)
• Page Start: 95
• Page End: 101
• Publication Date: 2015-11-25
• Subjects: chiral copper(II) complexes -- chirality transfer -- chiroptical property -- nitroaldol -- β‐nitroalcohol; Organometallic chemistry -- Periodicals; Organometallic compounds -- Periodicals; 547.05
• DOI: 10.1002/aoc.3404
• Languages: English
• ISSNs: 0268-2605

Abstract

Abstract : Enantiopure macrocyclic ligands were synthesized from (1 R, 2 R )‐(+)‐ and (1 S, 2 S )‐(−)‐diphenylethylenediamine with 3, 3'‐methylenebis(5‐( tert ‐butyl)‐2‐hydroxybenzaldehyde) and characterized. The chirality transfer and chiralinversion from ligand to copper(II) metal centre were studied using circular dichroism spectroscopy. The enantiopure binuclear copper(II) complexes (ΔΔ and ΛΛ) were used as catalysts for asymmetric nitroaldol reaction to generate β‐nitroalcohol with 88% yield and 67%enantioselectivity . Copyright © 2015 John Wiley & Sons, Ltd. Abstract : Geometrical chirality (ΔΔ and ΛΛ) at the Cu(II) metal centre of binuclear Cu(II) complexes was generated by chirality transfer from each of two ligands. The chiroptical properties were extensively studied using circular dichroism and optical rotatory dispersion. Their application as catalysts in asymmetric Henry reaction gives good yield and moderate enantioselectivity. Catalysts generate β‐nitroalcohol of different isomers with respect to the geometrical chirality at the Cu(II) metal centre used.