343-43-1Relevant articles and documents
Solid-state construction of zigzag periphery: Via intramolecular C-H insertion induced by alumina-mediated C-F activation
Akhmetov, Vladimir,Amsharov, Konstantin,F?rtsch, Andreas,Feofanov, Mikhail
, p. 12325 - 12328 (2021/11/30)
Caryl-F bond activation has become an important and quickly developing method for construction of carbon-based materials. We report that alumina-mediated C-F bond activation (AmCFA) enables construction of PAHs with zigzag periphery. This method includes
A comprehensive study of substituent effects on poly(dibenzofulvene)s
Wong, Michael Y.,Leung, Louis M.
, p. 512 - 520 (2017/02/05)
We herein report the first cross comparison of 14 poly(dibenzofulvene) derivatives (13 novel examples and the parent poly(dibenzofulvene)) in order to understand how the choice of substituent affects the physical properties of this interesting class of semiconducting polymers. Electron withdrawing substituents decreased the polymerization reactivity and resulted in very low molecular-weight products. Di-substituted poly(dibenzofulvene)s were found to be much less soluble than the mono-analogues which can be explained by the Hansen solubility parameter system. Analysis based on absorption, emission and electrochemistry profiles suggests that polymer solubility is a very important factor that controls the degree of stacking present in the polymer due to synthetic issues. For the first time, the thermal analysis of the parent poly(dibenzofulvene) and its derivatives is reported and it was believed that depolymerization occurred much earlier than the melting transition. We have also demonstrated the orthogonal synthesis of dibenzofulvene monomers using three distinct routes (lithiation, oxidation and Wittig) to cope with functional group compatibility.
Au-catalyzed biaryl coupling to generate 5- to 9-membered rings: Turnover-limiting reductive elimination versus π-complexation
Corrie, Tom J. A.,Ball, Liam T.,Russell, Christopher A.,Lloyd-Jones, Guy C.
supporting information, p. 245 - 254 (2017/05/29)
The intramolecular gold-catalyzed arylation of arenes by aryl-trimethylsilanes has been investigated from both mechanistic and preparative aspects. The reaction generates 5- to 9-membered rings, and of the 44 examples studied, 10 include a heteroatom (N, O). Tethering of the arene to the arylsilane provides not only a tool to probe the impact of the conformational flexibility of Ar-Au-Ar intermediates, via systematic modulation of the length of aryl-aryl linkage, but also the ability to arylate neutral and electron-poor arenes-substrates that do not react at all in the intermolecular process. Rendering the arylation intramolecular also results in phenomenologically simpler reaction kinetics, and overall these features have facilitated a detailed study of linear free energy relationships, kinetic isotope effects, and the first quantitative experimental data on the effects of aryl electron demand and conformational freedom on the rate of reductive elimination from diaryl-gold(III) species. The turnover-limiting step for the formation of a series of fluorene derivatives is sensitive to the reactivity of the arene and changes from reductive elimination to π-complexation for arenes bearing strongly electron-withdrawing substituents (σ > 0.43). Reductive elimination is accelerated by electron-donating substituents (ρ = -2.0) on one or both rings, with the individual σ-values being additive in nature. Longer and more flexible tethers between the two aryl rings result in faster reductive elimination from Ar-Au(X)-Ar and lead to the π-complexation of the arene by Ar-AuX2 becoming the turnover-limiting step.