已经测量了一系列取代的9-苯基芴的p K a值。在与以前的研究相结合,结果使建立的ħ -为25-97%的含水二甲亚砜含有氢氧化四甲铵酸度函数。结果表明,在更多水溶液中,基于苯胺指示剂的电离,该比例与酸度功能不平行。芴环中的取代基对烃酸度的影响大于9-苯基核中的取代基。通过使用改良的Hammett方程,取代基与烃酸度的影响相关,表明9-苯环与芴核的平面度之间的距离约为。 39°,接近分子轨道计算先前预测的值。
Direct C–H bond arylation of fluorenes with aryl chlorides catalyzed by N-heterocyclic carbene–palladium(<scp>ii</scp>)–1-methylimidazole complex and further transformation of the products in a one-pot procedure
作者:Ya-Yun Ji、Li-Li Lu、Yu-Chun Shi、Li-Xiong Shao
DOI:10.1039/c4ob01594k
日期:——
We report here the NHCâPd(II)âIm complex 1-catalyzed direct CâH bond functionalization of the C9 position of fluorenes with aryl chlorides and further transformation of the resulting products in a one-pot procedure. Under the optimal conditions, arylated fluorenes can be obtained in moderate to almost quantitative yields using various activated and unactivated (hetero)aryl chlorides as the arylating reagents. Furthermore, if the mixture from the arylation reaction is exposed to air, the C9-oxidized products can be obtained in acceptable to good yields in a one-pot procedure. In addition, alkyl groups can also be efficiently introduced to the above mixture from the arylation reaction, producing further C9-alkylated products in good to almost quantitative yields in a one-pot procedure, thus providing an expedient, inexpensive and practical strategy for the mono- and di-functionalization of fluorenes.
Acidity of hydrocarbons. Ionisation constants for some substituted 9-phenylfluorenes
作者:Anthony F. Cockerill、John E. Lamper
DOI:10.1039/j29710000503
日期:——
The pKa values of a series of substituted9-phenylfluorenes have been measured. In conjunction with earlier studies, the results enable the establishment of an H– acidity function for 25–97% aqueous dimethyl sulphoxide containing tetramethylammonium hydroxide. It is indicated that this scale does not parallel the acidity function based on the ionisation of aniline indicators in the more aqueous solutions
已经测量了一系列取代的9-苯基芴的p K a值。在与以前的研究相结合,结果使建立的ħ -为25-97%的含水二甲亚砜含有氢氧化四甲铵酸度函数。结果表明,在更多水溶液中,基于苯胺指示剂的电离,该比例与酸度功能不平行。芴环中的取代基对烃酸度的影响大于9-苯基核中的取代基。通过使用改良的Hammett方程,取代基与烃酸度的影响相关,表明9-苯环与芴核的平面度之间的距离约为。 39°,接近分子轨道计算先前预测的值。
KHMDS mediated synthesis of 9-arylfluorenes from dibenzothiophene dioxides and arylacetonitriles by tandem S<sub>N</sub>Ar-decyanation-based arylation
作者:Saketh Mylavarapu、Mamta Yadav、M. Bhanuchandra
DOI:10.1039/c8ob02355g
日期:——
A straightforward KHMDS mediated synthetic route to 9-arylfluorenes from readily available starting materials has been developed.
已开发出一种直接的KHMDS介导合成路线,可从易获得的起始材料合成9-芳基芴。
A simple and efficient synthesis of 9-arylfluorenes via metal-free reductive coupling of arylboronic acids and N-tosylhydrazones in situ
作者:Xu Shen、Ningning Gu、Ping Liu、Xiaowei Ma、Jianwei Xie、Yan Liu、Lin He、Bin Dai
DOI:10.1039/c5ra12099c
日期:——
efficient synthesis method of 9-arylfluorenes via metal-freereductive coupling of N-tosylhydrazones and arylboronic acids has been developed. This methodology is realized by a one-pot protocol in two steps involving the preparation of N-tosylhydrazones by reacting tosylhydrazide with 9-fluorenone derivatives, followed by the reductive coupling of arylboronic acid in the presence of potassium carbonate to