Synthesis and Characterization of Imidazolium Salts

The solvents were distilled, dried and stored according to standard procedures.²⁰ Unless otherwise stated, reagents were obtained from commercial sources and were used as received. The imidazolium salts were synthesized according to our previously reported method.^{14 (link)1}H, ¹³C NMR, and 2D-HSQC spectra were recorded with a Bruker Advance 300 spectrometer. Chemical shifts (δ) are reported in ppm with the residual solvent resonance signal: δ H/C 7.27 : 77.2 for CDCl₃; and δ H 4.79 for D₂O. Melting points were determined on a Reichert–Kofler hot-stage microscope and were uncorrected. Microanalytical data were obtained using an Exeter Analytical Inc. CE-440 microanalyzer. Infrared spectra were collected on an FTIR spectrometer Nicolet Nexus-470. Stille coupling and Suzuki–Miyaura reactions mixture were analyzed by gas–liquid chromatography using a Shimadzu GC-14B instrument equipped with a flame-ionization detector and a HP-5MS column (30 m × 0.25 mm × 0.25 mm), using nitrogen as carrier gas. Mass spectra (EI) were obtained at 70 eV on a Hewlett Packard HP-5890 GC/MS instrument equipped with a HP-5972 selective mass detector.