A tautomeric equilibrium between functionalized 2-formylphenylboronic acids and corresponding 1,3-dihydro-1,3-dihydroxybenzo[c][2,1]oxaboroles
作者:Sergiusz Luliński、Izabela Madura、Janusz Serwatowski、Halina Szatyłowicz、Janusz Zachara
DOI:10.1039/b611195e
日期:——
Functionalized 2-formylphenylboronic acids undergo an unprecedented tautomeric rearrangement in solution to form corresponding 1,3-dihydro-1,3-dihydroxybenzo[c][2,1]oxaboroles. X-Ray analyses of selected examples revealed diverse solid-state molecular structures from a planar open form with a hydrogen-bonded carbonyl group (X = 3-F) through a twisted conformer showing a weak carbonyl–boron interaction
功能化的2-甲酰基苯基硼酸在溶液中经历前所未有的互变异构重排,以形成相应的1,3-二氢-1,3-二羟基苯并[ c ] [2,1]氧杂硼酸。对选定示例的X射线分析显示,固态分子结构从带有氢键合羰基的平面开放形式(X = 3-F)到扭曲的构象异构体,表现出弱的羰基-硼相互作用(X = 3,5)。 -Br 2)生成环状氧杂硼酸酯衍生物(X = 3-Br)。可变温度1 H NMR光谱用于确定平衡常数以及焓和熵互变异构 在混合溶剂中 [D 6 ]丙酮–d 2 ö(95:5)。还已经通过DFT(B3LYP)和MP2方法对这一过程进行了计算。