title: Improved catalytic activity of homochiral dimeric cobalt-salen complex in hydrolytic kinetic resolution of terminal racemic epoxides.
abstract: Enantiomerically pure epoxides (99%, ee) and diols (98%, ee) from racemic epichlorohydrin, 1,2-epoxypropane, 1,2-epoxyhexane, 1,2-epoxyoctane, and 1,2-epoxydodecane were obtained in 2-12 h by hydrolytic kinetic resolution (HKR) using the recyclable dimeric homochiral Co(III)-salen complex 1' (0.2 mol %) derived from 5,5-(2',2'-dimethylpropane)-di-[(R,R)-{N-(3-tert-butylsalicylidine)-N'-(3',5'-di-tert-butylsalicylidine)}-1,2-cyclohexanediamine] with cobalt(II) acetate. Unlike its monomeric version, the catalyst could be recycled several times without loss in performance. The use of BF(4) as counter ion in HKR reactions was also investigated.
authors.affiliation: Silicates and Catalysis Discipline, Central Salt and Marine Chemicals Research Institute (CSMCRI), Bhavnagar, India. rkureshy@csmcri.org
authors.forename: Rukhsana I
authors.initials: RI
authors.lastname: Kureshy
authors.forename: Surendra
authors.initials: S
authors.lastname: Singh
authors.forename: Noor-Ul H
authors.initials: NU
authors.lastname: Khan
authors.forename: Sayed H R
authors.initials: SH
authors.lastname: Abdi
authors.forename: Irshad
authors.initials: I
authors.lastname: Ahmad
authors.forename: Achyut
authors.initials: A
authors.lastname: Bhatt
authors.forename: Raksh V
authors.initials: RV
authors.lastname: Jasra
mesh_terms: D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D019281:Dimerization; D004852:Epoxy Compounds / Q000737:chemistry*; D005029:Ethylenediamines / Q000138:chemical synthesis / Q000737:chemistry*; D006868:Hydrolysis; D007700:Kinetics; D015394:Molecular Structure; D013237:Stereoisomerism; D014867:Water / Q000737:chemistry
chemical_list: D004852:Epoxy Compounds; D005029:Ethylenediamines; D014867:Water; D003035:Cobalt; C011452:disalicylaldehyde ethylenediamine