It is well-recognized that N-heterocyclic carbene (NHC) ligands have provided a new dimension to the design of homogeneous catalysts. Part of the success of this type of ligands resides in the limitless access to a variety of topologies with tuned electronic properties, but also in the ability of a family of NHCs that are able to adapt their properties to the specific requirements of individual catalytic transformations. The term “smart” is used here to refer to switchable, multifunctional, adaptable, or tunable ligands and, in general, to all those ligands that are able to modify their steric or electronic properties to fulfill the requirements of a defined catalytic reaction. The purpose of this review is to comprehensively describe all types of smart NHC ligands by focusing attention on the catalytically relevant ligand-based reactivity.

中文翻译：

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催化中的智能N杂环碳原子配体

众所周知，N-杂环卡宾（NHC）配体为均相催化剂的设计提供了新的维度。这类配体成功的部分原因在于对具有可调电子特性的各种拓扑的无限制访问，而且还取决于能够使它们的特性适应单个催化转化的特定要求的一系列NHC的能力。术语“智能的”在本文中用于指代可切换的，多功能的，适应性的或可调的配体，并且通常是指能够修饰其空间或电子性质以满足定义的催化反应的要求的所有那些配体。这篇综述的目的是通过集中注意与催化相关的基于配体的反应性来全面描述所有类型的智能NHC配体。