The nine new heteroaryl-substituted imidazolidinium (1a–c), pyrimidinium (2a–c) and diazepinium (3a–c) salts as N-heterocyclic carbene (NHC) precursors were synthesized in good yields and entirely characterized using elemental analyses and conventional spectroscopic methods. In situ formed complexes from heterocyclic salts (1–3), Pd(OAc)2 and in the presence of KOBu t as a base were tested as catalysts for the Mizoroki–Heck coupling reaction in an aqueous media and very high yields were achieved. 1,3-Di(5-methylthiophen-2-ylmethyl)pyrimidinium hexafluorophosphate salt (2b) was structurally characterized by single-crystal X-ray diffraction. In the 2b compound (C16H21N2S2)+[PF6]−, the terminal thiophene rings are twisted with a dihedral angle of 72.8(3)°. In the pyrimidine ring, the three successive C atoms between the N atoms are disordered over two positions [occupancy ratio 0.753(12):0.247(12)]. In the crystal, neighboring molecules are linked by C–H…F hydrogen bonds, running along the b axis.
九种新的杂芳基取代的
咪唑啉铵盐(1a–c)、
嘧啶铵盐(2a–c)和二氮杂
萘铵盐(3a–c)作为N-杂环卡宾(NHC)前体以良好产率合成,并通过元素分析和常规光谱方法进行了全面表征。通过杂环盐(1–3)、Pd(OAc)2和KOBu t作为碱在原位形成的复合物被测试为
水相中的Mizoroki–Heck偶联反应催化剂,并获得了非常高的产率。1,3-二(5-甲基
噻吩-2-基甲基)
嘧啶六氟磷酸盐(2b)通过单晶X射线衍射进行结构表征。在化合物2b(
C16H21N2S2)+[PF6]−中,末端
噻吩环扭曲,二面角为72.8(3)°。在
嘧啶环中,N原子之间的三个连续C原子在两个位置上无序排列[占据比例0.753(12):0.247(12)]。在晶体中,相邻分子通过C–H…F氢键相连,沿b轴排列。