9-Azabicyclo[3.3.1]nonane N-Oxyl, ABNO
9-Azabicyclo[3.3.1]nonane N-Oxyl (ABNO) is a less hindered nitroxyl radical, that exhibits an enhanced reactivity compared with TEMPO.
Recent Literature
Cu/TEMPO catalyst systems show reduced reactivity in aerobic oxidation of
aliphatic and secondary alcohols. A catalyst system consisting of (MeObpy)CuOTf
and ABNO mediates aerobic oxidation of primary, secondary allylic, benzylic, and
aliphatic alcohols with nearly equal efficiency. The catalyst exhibits broad
functional group compatibility, and most reactions are complete within 1 h at
room temperature using ambient air as oxidant.
J. E. Steves, S. S. Stahl, J. Am. Chem. Soc., 2013,
135, 15742-15745.
The combination of Fe(NO3)3·9H2O and
9-azabicyclo[3.3.1]nonan-N-oxyl enables an efficient aerobic oxidation of
a broad range of primary and secondary alcohols to the corresponding aldehydes
and ketones at room temperature with ambient air as the oxidant.
L. Wang, S. Shang, G. Li, L. Ren, Y. Lv, S. Gao, J. Org. Chem.,
2016,
81, 2189-2193.
A modular Cu/ABNO catalyst system enables efficient aerobic oxidative coupling
of alcohols and amines to amides. All four permutations of benzylic/aliphatic
alcohols and primary/secondary amines are viable in this reaction, enabling
broad access to secondary and tertiary amides with excellent functional group
compatibility within short reaction time at rt.
S. L. Zultanski, J. Zhao, S. S. Stahl, J. Am. Chem. Soc., 2016,
138, 6416-6419.
A selective electrochemical aminoxyl-mediated Shono-type oxidation of
pyrrolidines provides pyrrolidinones with high selectivity and functional group
compatibility.
N. R. Deprez, D. J. Clausen, J.-X. Yan, F. Peng, S. Zhang, J. Kong, Y. Bai, Org. Lett., 2021, 23,
8834-8837.
Cu/nitroxyl catalysts promote a highly efficient and selective aerobic oxidative
lactonization of diols under mild reaction conditions using ambient air as the
oxidant. A Cu/ABNO catalyst system shows excellent reactivity with symmetrical
diols and hindered unsymmetrical diols, whereas a Cu/TEMPO catalyst system
displays excellent chemo- and regioselectivity for the oxidation of less
hindered unsymmetrical diols.
X. Xie, S. S. Stahl, J. Am. Chem. Soc., 2015,
137, 3767-3770.
A Cu/ABNO-catalyzed aerobic oxidative coupling of diols and a broad range of
primary amines provides N-substituted pyrroles. The reaction proceeds at
room temperature with an O2 balloon as the oxidant using commercially
available materials as the substrates and catalysts. The catalyst system offers
a good tolerance to sensitive functional groups.
W. Fu, L. Zhu, S. Tan, Z. Zhao, X. Yu, L. Wang, J. Org. Chem., 2022, 87,
13389-13395.
