Unexpected Migratory Insertion Reactions of M(alkyl)2 (M = Zn, Cd) and Diamidocarbenes

被引：7

作者：

Collins, Lee R. ^{[1
]}

Hierlmeier, Gabriele ^{[1
]}

Mahon, Mary F. ^{[1
]}

Riddlestone, Ian M. ^{[1
]}

Whittlesey, Michael K. ^{[1
]}

机构：

[1] Univ Bath, Dept Chem, Bath BA2 7AY, Avon, England

来源：

CHEMISTRY-A EUROPEAN JOURNAL | 2015年 / 21卷 / 08期

基金：

英国工程与自然科学研究理事会;

关键词：

alkyl ligands; cadmium; carbenes; migratory insertion; zinc; N-HETEROCYCLIC CARBENE; OLEFIN METATHESIS CATALYSTS; H ACTIVATION; COMPLEXES; LIGANDS; AMMONIA; P-4; REACTIVITY; DISCOVERY; CHEMISTRY;

D O I：

10.1002/chem.201406406

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The electrophilic character of free diamidocarbenes (DACs) allows them to activate inert bonds in small molecules, such as NH3 and P-4. Herein, we report that metal coordinated DACs also exhibit electrophilic reactivity, undergoing attack by Zn and Cd dialkyl precursors to afford the migratory insertion products [(6-MesDAC-R)MR] (M=Zn, Cd; R=Et, Me; Mes=mesityl). These species were formed via the spectroscopically characterised intermediates [(6-MesDAC)MR2], exhibiting barriers to migratory insertion which increase in the order MR2=ZnEt2 < ZnMe2 < CdMe2. Compound [(6-MesDAC-Me) CdMe] showed limited stability, undergoing deposition of Cd metal, by an apparent beta-H elimination pathway. These results raise doubts about the suitability of diamidocarbenes as ligands in catalytic reactions involving metal species bearing nucleophilic ligands (M-R, M-H).

引用

页码：3215 / 3218

页数：4

共 69 条

[1] Synthesis and reactivity of olefin metathesis catalysts bearing cyclic (alkyl) (amino) carbenes [J].