Preparation of bifunctional isocyanate hydroxamate linkers: synthesis of carbamate and urea tethered polyhydroxamic acid chelators
作者:Rasika Fernando、Jonathan M. Shirley、Emilio Torres、Hollie K. Jacobs、Aravamudan S. Gopalan
DOI:10.1016/j.tetlet.2012.09.025
日期:2012.11
Two novel bifunctional N-methylhydroxamate-isocyanate linkers 20 and 21 were prepared in good yield and high purity from the corresponding amine salts using a biphasic reaction with phosgene. The facile ring opening reaction of N-Boc lactams using the anion of O-benzylhydroxylamine gave the protected amino hydroxamates 6a and 6c in good yields. The selective methylation of the hydroxamate nitrogen in the presence of the N-Boc group in these intermediates could be readily accomplished. The utility of the linkers was clearly demonstrated by the synthesis of the carbamate-tethered trishydroxamic acid 27 and the urea-tethered 29. (C) 2012 Elsevier Ltd. All rights reserved.