Boc-Protected Amines via a Mild and Efficient One-Pot Curtius Rearrangement
Hélène Lebel* and Olivier Leogane
*Département de chimie, Université de Montréal, P.O. Box 6128, Station
Downtown, Montréal, Québec, Canada H3C 3J7, Email: helene.lebel
umontreal.ca
H. Lebel, O. Leogane, Org. Lett., 2005, 7, 4107-4110.
DOI: 10.1021/ol051428b (free Supporting Information)
Abstract
Tert-butyl carbamates are produced in high yields at low temperature by the reaction of a carboxylic acid with di-tert-butyl dicarbonate and sodium azide, which leads to an acyl azide intermediate. Subsequent Curtius rearrangement in the presence of tetrabutylammonium bromide and zinc(II) triflate and trapping of the isocyanate derivative gives the desired product. This method tolerates various functional groups.
see article for more examples
see article for more reactions
Curtius Rearrangement of Aromatic Carboxylic Acids to Access Protected Anilines and Aromatic Ureas
H. Lebel, O. Leogane, Org. Lett., 2006, 8, 5717-5720.
Key Words
Curtius Rearrangement, Boc-Protected Amines, Carbamates
ID: J54-Y2005-1350
