Modulation of the reactivity, stability and substrate- and enantioselectivity of an epoxidation catalyst by noncovalent dynamic attachment of a receptor functionality—aspects on the mechanism of the Jacobsen–Katsuki epoxidation applied to a supramolecular system
作者:Stefán Jónsson、Fabrice G. J. Odille、Per-Ola Norrby、Kenneth Wärnmark
DOI:10.1039/b518244a
日期:——
The synthesis of the components of the dynamic supramolecular hydrogen-bonded catalytic system 2 + 3 is described. The catalytic performance and substrate- and enantioselectivity of Mn(salen) catalyst 2 were investigated in the presence and absence of the Zn(porphyrin) receptor unit 3. The effects of pyridine and pyridine N-oxide donor ligands were also studied. Some aspects on the mechanism of the
描述了动态超分子氢键催化体系2 + 3的合成。在存在和不存在Zn(卟啉)受体单元3的情况下,研究了Mn(salen)催化剂2的催化性能以及底物和对映选择性。还研究了吡啶和吡啶N-氧化物供体配体的作用。在文献观察的基础上,介绍了雅各布森-胜木环氧化机理的某些方面,作为分析2的行为及其通过形成大环1与3进行调制的方法。一个完整的无金属体系缔合模型4 + 5驳斥了先前的假设,即在标准环氧化反应条件下2 + 3时,大环1是催化剂2的主要形式。