Categories: C=O Bond Formation > Synthesis of Ketones
Synthesis of α-keto carboxylic acids, esters and amides
| Related: |  |
 |
 |
Recent Literature
An efficient iodine-mediated oxidative esterification of acetophenones provides
various α-ketoesters and esters in high yields in the presence of potassium
xanthates. The potassium xanthate not only promotes oxidative esterification but
also provides an alkoxy moiety for the reaction.
X. Luo, R. He, Q. Liu, Y. Gao, J. Li, X. Chen, Z. Zhu, Y. Huang, Y. Li, J. Org. Chem., 2020, 85,
5220-5230.
Copper-catalyzed aerobic oxidative esterification of acetophenones with alcohols
using molecular oxygen gives a broad range of α-ketoesters in good yields.
Mechanism studies evealed that the carbonyl oxygen in the ester mainly
originated from dioxygen.
X. Xu, W. Ding, Y. Lin, Q. Song, Org. Lett.,
2015,
17, 516-519.
In the presence of nucleophiles (alcohols or amines), ion-supported (diacetoxyiodo)benzene
promoted sp3 C-H oxidation of nitromethyl aryl ketones to provide the
corresponding α-keto esters and amides in good yields. The reaction is
ecofriendly and offers mild conditions, short reaction times, and a recyclable
reagent.
X. Jang, B. Gan, J. Liu, Y. Xie,
Synlett, 2016, 27, 2737-2741.
Visible light promotes a green and mild conversion of β-ketonitriles into
α-ketoesters under catalyst-free conditions via singlet oxygen generation,
oxidative C-H bond functionalization, and C-C σ-bond cleavage.
C. Xu, N.-N. Zhang, X.-j. Li, Y.-q. Ge, P.-h. Diao, C. Guo,
Synlett, 2018, 29, 1065-1070.
A recyclable, bifunctional iron nanocomposite catalyzes an efficient synthesis
of α-keto acids via oxidation of alkenes using TBHP as oxidant. A variety of
alkenes with different functional groups were smoothly oxidized into their
corresponding α-keto acids in good yields.
T. Song, Z. Ma, X. Wang, Y. Yang, Org. Lett., 2021, 23,
5917-5921.
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.
Benzylimidates can directly be converted to primary α-ketoamides by using
molecular oxygen as an oxidant in the presence of copper(II) salt. The reaction
offers a wide substrate scope and operationally mild conditions.
Y. Kumar, M. Shaw, R. Thakur, A. Kumar, J. Org. Chem.,
2016, 81, 6617-6625.
A simple and efficient oxidative coupling of diazoesters and α-diazoketones
with NH4I provides primary oxamates and α-ketoamides in good yields. This metal-free protocol is performed
under mild conditions and has a wide substrate scope.
H. Wang, Y. Zhao, Y. Zheng, S. Fang, J. Li, X. Wan, J. Org. Chem., 2020, 85,
3050-3058.
The use of pyridine-N-oxides as oxidants under molecular iodine catalysis
enables a rapid, metal-free dioxygenation of ynamides. Furthermore, this
protocol could be extended to nonactivated alkynes, such as diarylacetylenes, to
provide various benzil derivatives.
S. W. Kim, T.-W. Um, S. Shin, J. Org. Chem., 2018, 83,
4703-4711.
2,3-Dichloropyridine N-oxide as oxygen transfer reagent enables gold(I)-catalyzed oxidation of alkynes to 1,2-dicarbonyls in
the absence of any acid additives and under mild conditions. The
developed strategy is also effective for ynamides, alkynyl ethers/thioethers,
and substrates bearing highly acid-sensitive groups. A one-pot
heterocyclization provides six-membered azaheterocycles.
A. Yu. Dubovtsev, N. V. Shcherbakov, D. V. Dar'in, V. Yu.
Kukushkin, J. Org. Chem., 2020, 85,
745-757.
An amination reaction of in situ generated gem-difluoro-enolates with
nitrosoarenes furnished α-ketoamides in very high yields. This nitroso aldol
reaction is very fast (typically completed within 5 min) and scalable and
tolerates various sensitive functional groups. Amination with azodicarboxylates
smoothly produced fluorinated α-amino ketones.
M. K. Reddy, I. Ramakrishna, M. Baidya, Org. Lett.,
2018, 20, 4579-4583.
Porphyrins catalyze a one-step conversion of β-enaminonitriles to
synthetically versatile α-keto amides in good yields under visible light
irradiation. The method is mild, cost-effective, and sustainable using air as
the sole reagent/oxidant. The reaction proceeds via an ene-type pathway
initiated by 1O2, followed by dehydration, imine
hydrolysis, and subsequent nucleophilic substitution of the cyanide.
R. Kumar, N. Grover, N. Jain, J. Org. Chem., 2024, 89,
4722-4732.
Related
The cross-coupling reaction of α-oxo acid chlorides with carbamoylsilanes
provides vicinal tricarbonyl amides in good yields under mild conditions. The
reaction of carbamoylsilanes with oxalyl chloride is accompanied by
decarbonylation to give vicinal tricarbonyl amides.
Y. Han, Y. Li, S. Han, P. Zhang, J. Chen, Synthesis, 2019, 51,
2977-2983.