N-heterocyclic carbene (NHC) complexes of group 4 transition metals.
N-heterocyclic carbene (NHC) complexes of group 4 transition metals.
复制标题
DOI：
10.1039/c4cs00441h
复制
发表时间：
2015-03
影响因子：
46.2
通讯作者：
Daodong Zhang;Guofu Zi
中科院分区：
文献类型：
--
作者：
Daodong Zhang;Guofu Zi
自稳定的n -杂环碳化合物（NHC）被发现以来，近二十年来，NHC在化学中的应用得到了迅速发展。这些有趣的化合物在有机金属化学中主要用作各种金属中心的配体，以及各种转化的有机催化剂。特别是四羧基过渡金属配合物受到了广泛的关注，近年来，四羧基配合物的开发取得了重大进展。这些4族nhc配合物因其独特的结构性质以及在有机转化和催化方面的潜在应用而受到关注。本文综述了NHC配体稳定早期过渡金属和具有单齿和多齿NHC配体的明确的4族金属配合物的优越设计策略。在这种情况下，描述了四种类型的nhc配合物，即碳官能化NHCs，氮官能化NHCs，氧官能化NHCs和氮/氧官能化不对称NHCs。此外，还介绍了4族nhc配合物作为催化剂在烯烃（co）聚合、丙交酯开环聚合、环氧化物与CO2共聚以及胺烯烃的氢胺化/环化反应中的应用。此外，还讨论了局限性和挑战。
Since the discovery of a stable N-heterocyclic carbene (NHC), the use of NHCs in chemistry has developed rapidly over the past two decades. These interesting compounds are predominantly employed in organometallic chemistry as ligands for various metal centers, and as organocatalysts for a variety of transformations. In particular, the NHC transition metal complexes have received widespread attention, and significant progress has been made in the development of group 4 NHC-complexes in the last few years. These group 4 NHC-complexes are of interest because of their unique structural properties, and their potential application in organic transformations and catalysis. This review covers the superior design strategies for NHC ligands to stabilize early transition metals and well-defined group 4 metal complexes with mono- and multi-dentate NHC ligands. In this context, four types of NHC-complexes, i.e., carbon-functionalized NHCs, nitrogen-functionalized NHCs, oxygen-functionalized NHCs and nitrogen/oxygen-functionalized unsymmetric NHCs, are described. In addition, the use of group 4 NHC-complexes as catalysts in olefin (co)polymerization, ring-opening polymerization of rac-lactide, copolymerization of epoxides and CO2, as well as hydroamination/cyclization of aminoalkenes, is presented. Furthermore, limitations and challenges are discussed.