Metal-free 5-exo-dig cyclization of propargyl urea using TBAF
摘要:
We present the first results of the intramolecular cyclization of propargyl ureas catalyzed by TBAF. Depending on the substituents close to the triple bond, imidazolone or methylene-imidazolidinone was obtained. The dual activation of the triple bond by interaction with TBAF via the cation-pi is thought to be responsible. (C) 2014 Elsevier Ltd. All rights reserved.