Synthesis and acid–base properties of a proton-bridged biaryl compound based on pyridylazulene
作者:Kazuki Ninomiya、Yumi Harada、Tomoaki Kanetou、Yuma Suenaga、Toshihiro Murafuji、Ryo Tsunashima
DOI:10.1039/c5nj01651g
日期:——
Herein, we report the synthesis of 1,1′-bi(2-pyridylazulene) (1), in which pyridyl moieties were coupled to a biaryl framework for hydrogen bonding between the two aryl skeletons. The two 2-pyridylazulene moieties in 1 were linked through facile aryl–aryl coupling between the 1- and 1′-positions of the azulene skeletons, where 1-haloazulene was stabilized by electron withdrawing pyridyl substitution
在这里,我们报告了1,1'-bi(2-pyridylazulene)(1)的合成,其中吡啶基部分被耦合到联芳构架,以在两个芳基骨架之间进行氢键键合。在两个2 pyridylazulene部分1是通过在骨架薁,其中1-haloazulene被吸电子取代吡啶基的稳定化的1-和1'-位置之间容易芳基-芳基偶联的联系。此外,单质子化的物种(单晶1H +成功获得)作为BF 4 -盐。153 K的X射线衍射分析表明,两个吡啶基部分之间存在分子内氢键,形成轴向手性物质的外消旋混合物。进行了DFT计算以了解氢键结构,并提出了质子运动的最小最小电势。在乙腈中对酸碱特性进行了研究,发现1展示了其吡啶基部分的两步质子化。与单体2-吡啶基azulene进行比较,证实了较强的1的基本特性。如1H +单晶所示,这归因于质子桥接的两个吡啶基部分的大环效应。。此外,在质子化下观察到与分子内转变有关的两种不同的能量转移。第