Boc-protected amines via a mild and efficient one-pot Curtius rearrangement.
[reaction: see text] The reaction of a carboxylic acid with di-tert-butyl dicarbonate and sodium azide allowed the formation of an acyl azide intermediate, which undergoes a Curtius rearrangement in the presence of tetrabutylammonium bromide and zinc(II) triflate. The trapping of the isocyanate derivative in the reaction mixture led to the desired tert-butyl carbamate in high yields at low temperature. These reaction conditions are compatible with a variety of substrates, including malonate derivatives, which provide access to protected amino acids.
Lebel
Hélène
H
Département de chimie, Université de Montréal, P.O. Box 6128, Station Downtown, Montréal, Québec, Canada H3C 3J7. helene.lebel@umontreal.ca
Leogane
Olivier
O
D000085:Acetates / Q000737:chemistry; D000218:Adamantane / Q000031:analogs & derivatives / Q000737:chemistry; D000588:Amines / Q000737:chemistry*; D002384:Catalysis; D008314:Malonates / Q000737:chemistry; D015394:Molecular Structure; D013379:Substrate Specificity; D015032:Zinc / Q000737:chemistry
C507636:1-adamantaneacetic acid; D000085:Acetates; D000588:Amines; D008314:Malonates; C030290:malonic acid; D015032:Zinc; D000218:Adamantane