Organic Letters · 2009 · 181 citations · 27 references
Natural SciencesChemistryMedicinal ChemistryGreen ChemistryOrganic ChemistryReaction EngineeringSafer Chemical SynthesisCarbonyl Rearrangement ReactionsClaisen RearrangementProcessing ConditionsRearrangement ReactionsRearrangement Techniques
Carbonyldiimidazole (CDI) was found to mediate the Lossen rearrangement of various hydroxamic acids to isocyanates. This process is experimentally simple and mild, with imidazole and CO(2) being the sole stoichiometric byproduct. Significant for large-scale application, the method avoids the use of hazardous reagents and thus represents a green alternative to standard processing conditions for the Curtius and Hofmann rearrangements.
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