Classical carbenes are usually described as neutral compounds featuring a divalent carbon with only six electrons in their valence shell. It was only in 1988 that our group prepared the first isolable example, in which the carbene center was stabilized by a push–pull effect, using a phosphino and a silyl substituent. In the last 30 years, a myriad of acyclic and cyclic push–pull and push–push carbenes, bearing different heteroatom substituents, have been isolated. Among them, the so-called N-heterocyclic carbenes (NHCs), which include cyclic (alkyl)(amino)carbenes (CAACs), are arguably the most popular. They have found a vast number of applications ranging from catalysis to material science, and even in medicine.

中文翻译：

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1 H -1,2,3-三唑-5-亚烷基：现成的中离子卡宾

传统的卡宾通常被描述为中性化合物，其二价碳原子的化合价壳中只有六个电子。直到1988年，我们小组才准备了第一个可分离的实例，其中使用膦基和甲硅烷基取代基通过推挽效应使卡宾中心稳定。在过去的30年中，已经分离出无数个带有不同杂原子取代基的无环和环状推拉和推推卡宾。其中，所谓的N-杂环卡宾（NHC），其中包括环状（烷基）（氨基）卡宾（CAAC），可以说是最受欢迎的。他们发现了从催化到材料科学甚至医学领域的大量应用。