Reductive cleavage of N-O bonds in hydroxylamines and hydroxamic acid derivatives using samarium diiodide

An efficient process for the reductive cleavage of N-O bonds using samarium diiodide is detailed for a variety of structural types to define the scope and limitations of the method. The reduction is shown to be compatible wit h base sensitive substrates such as trifluoroacetamide derivatives, which c annot be reduced satisfactorily using aluminum amalgam or sodium amalgam. D irect quenching of the reduction mixture with acylating agents is demonstra ted to provide high yields of protected amines in a one-pot process from th e N-O derivatives. (C) 1999 Elsevier Science Ltd. All rights reserved.