Green and Efficient Methods for One-Pot Aerobic Oxidative Synthesis of Benzimidazoles from Alcohols with TEMPO-PEG4000-NHC-Cu(II) Complex in Water

In this article, an amphiphilic catalyst TEMPO-PEG4000-NHC-Cu(II) [2,2,6,6-tetramethylpiperidine-1-oxyl/polyethylene glycol/N-heterocyclic carbene] complex was synthesized and used as a highly efficient catalyst for one-pot aerobic oxidative synthesis of benzimidazoles from alcohols. The reactions were applicable in water with good yields in the presence of catalyst (5 mol%). Moreover, the catalyst was easily recovered from the reaction mixture and reused with almost consistent activity.