Categories: C-N Bond Formation > Synthesis of amides >
Synthesis of amides by rearrangements, hydrolysis, or oxidation
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Recent Literature
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 Cu2O-catalyzed aerobic oxidative decarboxylative ammoxidation
of phenylacetic acids and α-hydroxyphenylacetic acids enables the synthesis of
various primary benzamides in good yields. This one-pot domino protocol
combines decarboxylation, dioxygen activation, oxidative C-H bond
functionalization, and amidation reactions.
Q. Song, Q. Feng, K. Yang, Org. Lett., 2014,
16, 624-627.
A simple ruthenium catalyst mediates a direct coupling between an alcohol and an
amine with the liberation of two molecules of dihydrogen. The active catalyst is
generated in situ from an easily available ruthenium complex, an N-heterocyclic
carbene and a phosphine. The reaction allows primary alcohols to be coupled with
primary alkylamines to afford secondary amides in good yields.
L. U. Nordstrřm, H. Vogt, R. Madsen, J. Am. Chem. Soc., 2008,
130, 17672-17673.
An in situ generated catalyst from readily available RuH2(PPh3)4,
an N-heterocyclic carbene (NHC) precursor, NaH, and acetonitrile showed
high activity for the amide synthesis directly from either alcohols or aldehydes
with amines.
S. Muthaiah, S. C. Ghosh, J.-E. Jee, C. Chen, J. Zahng, S. H. Hong, J. Org. Chem., 2010,
75, 3002-3006.
Hypervalent iodine reagents promote a facile and efficient transformation of
primary amides to secondary amides. The hypervalent iodine reagent mediates a
Hofmann-type rearrangement to an isocyanate intermediate, which is subsequently
trapped by an in situ generated carboxylic acid from the hypervalent iodine
reagent to provide the corresponding secondary amides.
X. Wang, P. Yang, B. Hu, Q. Zhang, D. Li, J. Org. Chem., 2021, 86,
2820-2826.
Cu(OTf)2-Catalyzed Beckmann Rearrangement of Ketones Using
Hydroxylamine-O-sulfonic Acid (HOSA)
S. Munnuri, S. Verma, D. Chandra, R. R. Anugu, J. R. Falck, J. L. Jat, Synthesis, 2019, 51,
3709-3714.
In a completely atom-economical and redox-neutral catalytic amide synthesis from
an alcohol and a nitrile, the amide C–N bond is efficiently formed between the
nitrogen atom of nitrile and the α-carbon of alcohol, with the help of an
N-heterocyclic carbene-based ruthenium catalyst, without a single byproduct.
B. Kang, Z. Fu, S. H. Hong, J. Am. Chem. Soc., 2013,
135, 11704-11707.
An efficient, metal-free domino protocol for the synthesis of benzamides from
ethylarenes proceeds through the formation of triiodomethyl ketone intermediate
in the presence of iodine as the promoter and TBHP as an oxidant followed by
nucleophilic substitution with aqueous ammonia. This operationally simple,
functional-group-tolerant tandem approach provides an easy access to the broad
range of biologically important benzamides.
K. S. Vadagaonkar, H. P. Kalmode, S. Prakash, A. C. Chaskar,
Synlett, 2015, 26, 1677-1682.
Direct Transformation of Ethylarenes into Primary Aromatic Amides with N-Bromosuccinimide
and I2-Aqueous NH3
S. Shimokawa, Y. Kawagoe, K. Moriyama, H. Togo, Org. Lett., 2016, 18,
784-787.
CpRuCl(PPh3)2 catalyzes reactions of terminal alkynes
with primary and secondary amines to afford the corresponding amides in the
presence of 4-picoline N-oxide. The reactions occur in chlorinated
solvent and aqueous medium, showing applications in peptide chemistry.
A. Álvarez-Pérez, M. A. Esteruelas, S. Izquierdo, J. A.
Varela, C. Saá,
Org. Lett., 2019, 21, 5346-5350.
In an unusual oxidative coupling reaction of isocyanide and toluene derivatives
using tetrabutylammonium iodide (TBAI) as a catalyst, the isocyano group acts
formally as an N1 synthon, thus expanding the reactivity profile of isocyanides.
Z. Liu, X. Zhang, J. Li, F. Li, C. Li, X. Jia, J. Li, Org. Lett.,
2016, 18, 4032-4035.
A facile copper-catalyzed ipso-amidation of arylboronic acids with
nitriles enables a highly efficient and economical synthesis of N-aryl
amides with a broad substrate scope.
Y. Qiao, G. Li, S. Liu, Y. Yangkai, J. Tu, F. Xu, Synthesis, 2017,
49, 1834-1838.
The use of tert-butyl hydroperoxide as an oxidant and an inexpensive and
air stable copper catalyst enables a simple and efficient protocol for the
oxidative amidation of commercially affordable alcohols to Weinreb amides in
very good yields. The reaction tolerates various functional groups.
S. L. Yedage, B. M. Bhanage, Synthesis, 2015, 47,
526-532.
A dimethyl sulfoxide (DMSO)-promoted oxidative amidation reaction between
2-oxoaldehydes and amines under metal-free conditions enables an efficient
synthesis of α-ketoamides. Mechanistic studies supported an iminium ion
intermediate that reacts with DMSO to provide the C1-oxygen atom of
the product.
N. Mupparapu, S. Khan, S. Battula, M.
Kushwaha, A. P. Gupta, Q. N. Ahmed, R. A. Vishwakarma, Org. Lett., 2014,
16, 1152-1155.
A Cu-catalyzed oxidative amidation-diketonization reaction of terminal alkynes
leads to α-ketoamides. In this copper-catalyzed radical process, O2
not only participates as the ideal oxidant but also undergoes dioxygen
activation under ambient conditions.
C. Zhang, N. Jiao, J. Am. Chem. Soc., 2010,
132, 28-29.
A copper-catalyzed one-pot strategy for the synthesis of α-ketoamides from
1-arylethanols is highly efficient and delivers product in very good yields via
alcohol oxidation, sp3 C-H oxidation, and oxidative amidation.
N. Sharma, S. S. Kotha, N. Lahiri, G. Sekar, Synthesis, 2015, 47,
726-736.
The combination of zinc powder as reductant and sodium chlorate as oxidant was
used to provide an environmentally friendly, effective, and convenient method
for the synthesis of aromatic amides in good yields from nitroarenes and
aldehydes in a green solvent under atmospheric conditions. Reductants and
oxidants with opposing properties can be used together without any adverse
effects. In addition, a cooperation seems to improve the yield.
G. Sheng, X. Wu, X. Cai, W. Zhang, Synthesis, 2015, 47,
949-954.
A wide range of aldoximes has been converted into the corresponding amides in
high yield and selectivity using the ruthenium-based catalyst Ru(PPh3)3(CO)H2/dppe/TsOH
with catalyst loading as low as 0.04 mol%.
N. A. Owston, A. J. Parker, J. M. J. Williams, Org. Lett., 2007,
9, 3599-3601.
[Ir(Cp*)Cl2]2 catalyzes the rearrangement of oximes to
furnish amides. An iridium-catalyzed transfer
hydrogenation between alcohols and styrene and the subsequent formation of an
oxime allows the conversion of alcohols
into amides in a one-pot process.
N. A. Owston, A. J. Parker, J. M. J. Williams, Org. Lett., 2007,
9, 73-75.
A one-carbon homologation of an alcohol to the extended carboxylic acid, ester,
or amide involves a Mitsunobu reaction with an alkoxymalononitrile, followed by
unmasking in the presence of a suitable nucleophile. The homologation and
unmasking can even be performed in a one-pot process in high yield.
N. Kagawa, A. E. Nibbs, V. H. Rawal, Org. Lett.,
2016, 18, 2363-2366.