Synthesis of β-azidoketones, β-azidoacids and related compounds
A chiral (salen)Al complex catalyzes the highly enantioselective conjugate addition of carbon- and nitrogen-based nucleophiles to various acyclic α,β-unsaturated ketones providing access to a wide range of useful chiral building blocks in high yield and enantiomeric excess.
M. S. Taylor, D. N. Zalatan, A. M. Lerchner, E. N. Jacobsen, J. Am. Chem. Soc., 2005, 127, 1313-1317.
Amberlite IRA900N3 is an excellent and recyclable organocatalyst for the azidation of α,β-unsaturated ketones with trimethylsilyl azide under solvent-free conditions. This procedure is a green tool for the preparation of β-azido ketones under mild conditions with good yields.
L. Castrica, F. Fringuelli, L. Gregoli, F. Pizzo, L. Vaccaro, J. Org. Chem., 2006, 71, 9536-9539.
A mild oxidation of selected anions (N3-, SCN-, I-, and Br-) by ceric ammonium nitrate (CAN) in the presence of substituted cyclopropyl alcohols provides β-functionalized ketones in short reaction times. This method provides an alternative pathway to important starting materials and intermediates in organic synthesis.
J. Jiao, L. X. Nguyen, D. R. Patterson, R. A. Flowers II, Org. Lett., 2007, 9, 1323-1326.
Chiral N,N'-dioxide/Fe(OTf)2 complexes catalyze an unprecedented highly diastereo- and enantioselective bromoazidation of α,β-unsaturated ketones. An array of aryl, heteroaryl, and alkyl substituted α,β-unsaturated ketones were transformed to the corresponding α-bromo-β-azido ketones in high yields with excellent diastereo- and enantioselectivities. The catalytic system was also applicable for chloroazidations and iodoazidations.
P. Zhou, L. Lin, L. Chen, X. Zhong, X. Liu, X. Feng, J. Am. Chem. Soc., 2017, 139, 13414-13419.