Synthesis of Precursor Imidazolium Salts for the Synthesis of N-heterocyclic Carbines Used as Ligands for the Enantioselective Preparation of Heterosteroids Compounds

摘要

The imidazolium salts 1-phenyl-3-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)propyl)-1H-imidazol-3-ium bromide (4), and 1-(pyrimidin-2-yl)-3-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)propyl)-1H-imidazol-3-ium bromide (5) were respectively prepared by coupling reaction of the precursors 1-phenyl-1H-imidazole (1) and 2-(1H-imidazol-1-yl)pyrimidine (2) with 2-(3-Bromopropyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane(3). The purity of these compounds was confirmed by spectroscopic data. The NMR spectra showed all the signals and the structures were confirmed by HRMS.