Bromobenzene

DIB-ET was synthesized in our laboratory according to the previously reported method by our research group. 12 Bromobenzene, o-bromoanisole, p-bromoanisole, o-bromotoluene, p-bromotoluene, p-chloroanisole, p-chlorotoluene, N,Ndiisopropylethylamine (DIPEA), iodobenzene, p-iodoanisole and p-iodotoluene were purchased from Tokyo Chemical Industries (Tokyo). Chrolobenzene, tris{tris[3,5-bis(trifluoromethyl)phenyl]phosphine}palladium (super stable Pd catalyst), 1,4-dioxane, and o-iodoanisole were from Wako (Tokyo). m-Bromoanisole, copper (I) iodide (CuI) and acetonitrile were from Kanto Chemical (Tokyo). m-Bromotoluene was purchased from Sigma (St. Louis, MO). All of the used chemicals were of the highest purity and quality available, while the purities of the tested aryl halide were 98%, excluding Bromobenzene (99%) and p-bromoanisole (97%).
The synthesis and characterization of the aryl halides authentic derivatives of DIB-ET are described in Supporting Information.
Aryl halides standard solutions, DIB-ET (3.0 mM), super stable Pd (2.5 mM), CuI (0.5 mM) and DIPEA (50 mM) reagent solutions were prepared in dioxane.

Imidazolium bromide as a MS precursor was synthesized according to the literature method 24) . Pd (OAc) 2 (＞ 97.0％) , NaBr (99.9％) , dimethyl sulfoxide (99.0％) , trimethylamine (99.0％) , dichloromethane (99.0％) , methanol (99.5％) , chloroform (99.0％) , iodobenzene (97.0％) , chlorobenzene (99.0％) , and 4-iodoacetophenone (90.0％) were purchased from Wako pure Chemical Industries, Ltd., Japan. Bromobenzene (99.0％) , p-iodoanisole (96.0％) , 4-iodobenzoic acid (＞98.0％) , and methyl acrylate (＞ 99.0％) were procured from Tokyo Chemical Industry Co., Ltd., Japan. All chemicals were used as received.