Synthesis of α-azidoketones, α-azidoacids and related compounds
Chiral tertiary α-hydroxy esters were transformed to α-azido esters by Mitsunobu reaction with HN3. Reactions proceed at room temperature with high chemical yield using 1,1-(azodicarbonyl)dipiperidine (ADDP) and trimethylphosphine (PMe3) with complete inversion of configuration at the α-carbon. Several α,α-disubstituted amino acids were synthesized in high overall chemical yield and optical purity.
J. E. Green, D. M. Bender, S. Jackson, M. J. O'Donnell, J. R. McCarthy, Org. Lett., 2009, 11, 807-810.
A mild and rapid formal electrophilic α-azidation of 1,3-dicarbonyl compounds using commercially available Bu4NN3 as the azide source is mediated by (diacetoxyiodo)benzene. The reaction conditions are Bäcklund to the ones employed in analogous halogenations with Et4NX (X = Cl, Br, I).
M. J. Galligan, R. Akula, H. Ibrahim, Org. Lett., 2014, 16, 600-603.
The reaction of 1,3-dicarbonyl compounds with molecular iodine and sodium azide in aqueous DMSO provides a general access to a broad range of geminal diazides with various structural motifs including sterically demanding substituents and ordinary functional groups. The diazidation of 1,3-dicarbonyls can be selectively achieved even in the presence of other 1,3-dicarbonyls with substituents at 2-position.
H. Erhardt, A. P. Häring, A. Kotthaus, M. Roggel, M. L. Tong, P. Biallas, M. Jübermann, F. Mohr, S. F. Kirsch, J. Org. Chem., 2015, 80, 12462-12469.