Carbodicarbenes: Unexpected π-Accepting Ability during Reactivity with Small Molecules
Carbodicarbenes: Unexpected π-Accepting Ability during Reactivity with Small Molecules
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DOI：
10.1021/jacs.7b08031
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发表时间：
2017-09-13
影响因子：
15
通讯作者：
Ong, Tiow-Gan
中科院分区：
文献类型：
--
作者：
Chen, Wen-Ching;Shih, Wei-Chih;Ong, Tiow-Gan
碳二卡宾，探索较少的成员的卡宾络合物/配体家族的调查产生了意想不到的电子功能和伴随的反应性。观察到的1，2-加成的E-H键（E = B，C，Si）在碳的中心碳和侧翼的N-杂环卡宾（NHC）片段，结合单晶X-射线研究的模型Pd配合物强烈表明，在NHC部分的中心碳的π-接受能力的显着水平。该特征是典型的NHC的非典型特征，其是强σ供体，仅具有名义上的π接受能力。未预料到的π-酸性对于产生碳二卡宾至关重要，其反应性更常见于受抑刘易斯对（FLP）而不是更密切相关的NHC和环状（烷基）（氨基）卡宾（CAAC）。
An investigation of carbodicarbenes, the less explored member of the carbenic complex/ligand family has yielded unexpected electronic features and concomitant reactivity. Observed 1,2-addition of E-H bonds (E = B, C, Si) across the carbone central carbon and that of the flanking N-heterocyclic carbene (NHC) fragment, combined with single-crystal X-ray studies of a model Pd complex strongly suggests a significant level of pi-accepting ability at the central carbon of the NHC moiety. This feature is atypical of classic NHCs, which are strong sigma-donors, with only nominal pi-accepting ability. The unanticipated pi-acidity is critical for engendering carbodicarbenes with reactivity more commonly observed with frustrated Lewis pairs (FLPs) rather than the more closely related NHCs and cyclic (alkyl)(amino)carbenes (CAACs).