Three newpalladium catalysts, prepared via reactions of PdCl2 with readily obtained and inexpensive dicationic imidazolium salts, have been developed for the Suzuki reaction. The pre-catalyst was formed in situ using the imidazolium ligand, base and Pd metal precursor in 1,4-dioxane. This palladium catalyst provides a convenient and general method for the synthesis of biaryls from aryl bromides, activated
A series of seven-membered ditopic ring-expanded N-heterocycliccarbene (dre-NHC) precursors, bearing sterically demanding and electron-rich aryl groups, were synthesised in moderate yields via the reaction of 1,2,4,5-tetrakis(bromomethyl)benzene with the corresponding N,N′-diarylformamidines in the presence of K2CO3 in acetonitrile under an air atmosphere. All new compounds were characterised by HRMS
一系列的7元双中心环扩展ñ -杂环卡宾(DRE-NHC)的前体,轴承空间要求和富电子的芳基,是在中等产率合成通过的1,2,4,5-四反应(在空气气氛下,在乙腈中,在K 2 CO 3存在下,将溴甲基)苯与相应的N,N'-二芳基甲am 。所有新化合物均通过HRMS,NMR光谱和微分析以及化合物1c的X射线晶体学进行了表征。还研究了用于芳基氯与各种硼酸的Suzuki-Miyaura偶联反应的有效催化体系的发展。原位生成的dre-NHC配体。
Baroni,E.E. et al., Journal of Organic Chemistry USSR (English Translation), 1971, vol. 7, p. 2486 - 2489