Ytterbium triflate as an efficient catalyst for one-pot synthesis of substituted imidazoles through three-component condensation of benzil, aldehydes and ammonium acetate

Yb(OTf)(3) has been found to be an extremely efficient catalyst for the preparation of imidazoles derivatives via three-component coupling reactions of benzil, aldehydes and ammonium acetate under mild conditions. The process presented here is operationally simple, environmentally benign and has excellent yield. Furthermore, the catalyst can be recovered conveniently and reused for at least three reaction cycles without any loss of activity. (c) 2006 Elsevier B.V. All rights reserved.