Ay, S. and Ziegert, R. E. and Zhang, H. and Niege, M. and Rissanen, K. and Fink, K. and Kubas, A. and Gschwind, Ruth M. and Brase, S. (2010) NMR-Spectroscopic and Solid-State Investigations of Cometal-Free Asymmetric Conjugate Addition: A Dinuclear Paracyclophaneimine Zinc Methyl Complex. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 132 (37). pp. 12899-12905. ISSN 0002-7863,
Full text not available from this repository. (Request a copy)Abstract
We present herein the first indications for dimeric structures in cometal-free asymmetric conjugate addition reactions of dialkylzinc reagents with aldehydes. These are revealed by nonlinear effect (NLE) studies. A monomer dimer equilibrium can be assumed which explains the increase of the ee value in the product over time. Also, DOSY NMR spectroscopic measurements indicate the existence of the catalyst as [LZnEt](n) complexes in solution. Additionally, the first X-ray structure of a zinc complex with a [2.2]paracyclophane ligand was determined. The structures of the zinc complexes are supported by DFT calculations of monomeric and dimeric species.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | GRIGNARD-REAGENTS; ENANTIOSELECTIVE ADDITION; DIETHYL-ETHER; LIGANDS; ALDEHYDES; ENONES; BENZALDEHYDE; DIALKYLZINCS; AGGREGATION; CATALYSIS; |
| Subjects: | 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institut für Organische Chemie > Arbeitskreis Prof. Dr. Ruth Gschwind |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 13 Jul 2020 06:52 |
| Last Modified: | 13 Jul 2020 06:52 |
| URI: | https://pred.uni-regensburg.de/id/eprint/24166 |
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