NMR-Spectroscopic and Solid-State Investigations of Cometal-Free Asymmetric Conjugate Addition: A Dinuclear Paracyclophaneimine Zinc Methyl Complex

被引：27

作者：

Ay, S. ^{[1
]}

Ziegert, R. E. ^{[1
]}

Zhang, H. ^{[2
]}

Niege, M. ^{[3
]}

Rissanen, K. ^{[4
]}

Fink, K. ^{[5
]}

Kubas, A. ^{[5
]}

Gschwind, R. M. ^{[2
]}

Brase, S. ^{[1
]}

机构：

[1] Karlsruhe Inst Technol KIT, Inst Organ Chem, D-76131 Karlsruhe, Germany

[2] Univ Regensburg, Inst Organ Chem, D-93040 Regensburg, Germany

[3] Univ Helsinki, Inorgan Chem Lab, FIN-00014 Helsinki, Finland

[4] Univ Jyvaskyla, Organ Chem Lab, FIN-40014 Jyvaskyla, Finland

[5] Karlsruhe Inst Technol KIT, Inst Nanotechnol INT, D-76344 Eggenstein Leopoldshafen, Germany

来源：

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | 2010年 / 132卷 / 37期

关键词：

ENANTIOSELECTIVE ADDITION; GRIGNARD-REAGENTS; LIGANDS; DIALKYLZINCS; BENZALDEHYDE; AGGREGATION; CATALYSTS; PLANAR; REACTIVITY; DIFFUSION;

D O I：

10.1021/ja1032502

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

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.

引用

页码：12899 / 12905

页数：7