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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(5):1318-1322
We developed the novel one‐pot synthetic method of substituted triptycenes by the reaction of ynolates and arynes. This four‐step process involves three cycloadditions and electrocyclic ring opening of the strained Dewar anthracene. Each of the three related but structurally distinct classes of nucleophiles (ynolate, enolate, and anthracenolate) reacts with o‐benzyne in the same predictable manner controlled by chelation and negative hyperconjugation. The resulting functionalized C3‐symmetrical triptycenes hold promise in the design of functional materials. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(27):7975-7978
Hyperconjugative, steric, and electrostatic effects were evaluated as possible sources of the helicity in linear perfluorinated alkanes through analysis of natural bond orbitals and classical electrostatics. Contrary to previous rationalizations, which indicate dominating steric or electrostatic effects, this analysis indicates that hyperconjugative stabilization through σCC→σ*CF interactions are the underlying driving force for the origin of the observed helicity in perfluoroalkanes. 相似文献
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Junxia Li Ronglin Pang Zhifang Li Guoqiao Lai Xu‐Qiong Xiao Thomas Müller 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(5):1411-1415
The synthesis of a series of 1,2‐diamino‐o‐carboranes ( 1 – 4 ) is reported. The molecular structures of these diamino‐o‐carboranes are remarkable as the inner‐cluster C?C bonds are all ultra‐long (162.7–193.1 pm) and vary substantially with small variations in the substituents. The results of quantum mechanical investigations suggest that the origin of the bond elongation is significant in‐plane negative hyperconjugation of lone pairs of the nitrogen substituents with the σ* orbitals of the C?C bonds in o‐carboranes. 相似文献