Reusing meta-terphenyl ligands: Synthesis, metalation and recycling of 5-pyrrolidino-m-terphenyl

5-pyrrolidino-m-terphenyl (1) is synthesized via a Buchwald-Hartwig cross-coupling reaction. This terphenyl readily halogenated under ambient conditions with tetrabutylammonium tribromide to generate 4-pyrrolidino-2,6-diphenylbromobenzene (2). The reaction of (2) magnesium results in the conversion its corresponding Grignard reagent (3). Quenching (3) water recovery (1), demonstrating ability recycle this m-terphenyl ligand through halogenation-metalation-hydrolysis cycle. structure all three compounds were confirmed by 1H and 13C NMR single-crystal X-ray diffraction.