title: Synthesis and characterization of new chiral Cu(ii)-N4 complexes and their application in the asymmetric aza-Henry reaction.
abstract: Cu(ii) Schiff base complexes Cu(ii)- and Cu(ii)- based on 2-acetyl pyridine with both (1R,2R)-1,2-diaminocyclohexane and (1S,2S)-1,2-diaminocyclohexane were synthesized in a single step. Subsequent reduction of ligands and with NaBH4 followed by complexation with Cu(OTf)2 resulted in generation of two more additional chiral centers in complexes Cu(ii)- and Cu(ii)-. The ligands and their corresponding complexes were well characterized by several spectral techniques like (1)H-NMR, (13)C-NMR, LC-MS, CD, UV-Vis spectroscopy and microanalysis. The respective Cu(ii) complexes derived from ligands and were investigated using both the solution and solid state EPR spectra. The particular orientation of the reduced complex with Cu(OTf)2 was confirmed by the X-ray crystal structure of the corresponding complex. All the catalytic protocols were applied in the asymmetric aza-Henry reaction to evaluate the catalytic properties of the Cu(ii) complexes in the present study.
authors.affiliation: Discipline of Inorganic Materials and Catalysis, Central Salt and Marine Chemicals Research Institute (CSIR-CSMCRI), Bhavnagar-364 021, Gujarat, India. rukhsana93@yahoo.co.in.
authors.forename: Anjan
authors.initials: A
authors.lastname: Das
authors.forename: Rukhsana I
authors.initials: RI
authors.lastname: Kureshy
authors.forename: Nabin Ch
authors.initials: NCh
authors.lastname: Maity
authors.forename: P S
authors.initials: PS
authors.lastname: Subramanian
authors.forename: Noor-ul H
authors.initials: NU
authors.lastname: Khan
authors.forename: Sayed H R
authors.initials: SH
authors.lastname: Abdi
authors.forename: E
authors.initials: E
authors.lastname: Suresh
authors.forename: Hari C
authors.initials: HC
authors.lastname: Bajaj