Categories: C=O Bond Formation >
Synthesis of esters
Name Reactions
Recent Literature
N-Heterocyclic carbenes catalyze the oxidation of various allylic, propargylic,
and benzylic alcohols to esters with manganese(IV) oxide in excellent yields.
Saturated esters can also be accessed from aldehydes using this method. A
desymmetration of meso-1,2-diols using a chiral catalyst is described.
B. E. Maki, A. Chan, E. M. Phillips, K. A. Scheidt, Org. Lett., 2007,
9, 371-374.
Screening of simple binary and ternary admixtures of Pd/charcoal in combination
with one or two metal and/or metalloid components as the catalyst for aerobic
oxidative methyl esterification of primary alcohols revealed two very effective
catalyst compositions. One was used in batch aerobic oxidation reactions,
whereas the other achieved nearly 60 000 turnovers in a continuous-flow
packed-bed reactor with no apparent loss of catalytic activity.
D. S. Mannel, M. S. Ahmed, T. W. Root, S. S. Stahl, J. Am. Chem. Soc., 2017,
139, 1690-1698.
A readily accessible catalyst system consisting of Pd/charcoal in combination
with bismuth(III) nitrate and tellurium metal enables an efficient aerobic
oxidative methyl esterification of primary alcohols, exhibits a broad substrate
scope, and is effective with both activated and unactivated alcohols bearing
diverse functional groups. The Bi and Te additives significantly increase the
reaction rate, selectivity, and overall product yields.
A. B. Powell, S. S. Stahl, Org. Lett., 2013,
15, 5072-5075.
Oxidative methyl esterification of primary alcohols and diols with methanol in
the presence of acetone as a hydrogen acceptor was successfully achieved under
catalysis of an iridium complex combined with 2-(methylamino)ethanol (MAE).
N. Yamamoto, Y. Obora, Y. Ishii, J. Org. Chem., 2011,
76, 2937-2941.
The use of tert-butyl hydroperoxide (TBHP) as a terminal oxidant in the
presence of catalytic amount of tetrabutylammonium iodide and imidazole enables
a transition-metal-free synthesis of aryl esters in high yield starting from
benzylic primary alcohols and aliphatic alcohols. These reactions are highly
chemoselective and tolerate a wide range of substituents.
S. Nandy, A. Ghatak, A. K. Das, S. Bhar, Synlett, 2018, 29,
2208-2212.
A highly effective synthesis of methyl esters from benzylic alcohols, aldehydes,
or acids via copper-catalyzed C-C cleavage from tert-butyl hydroperoxide
is easily accessible and practical and offers an alternative to the traditional
way.
Y. Zhu, H. Yan, L. Lu, D. Liu, G. Rong, J. Mao, J. Org. Chem., 2013,
78, 9898-9905.
In a Fe-catalyzed aerobic oxidative esterifications of arylacetonitriles, acyl
electrophiles were in situ generated via chemoselective C(CO)-CN bond cleavage.
Alcohols, alkoxsilanes, silicate esters, or borate esters can be acylated to the
corresponding aryl esters in good to excellent yields under molecular oxygen.
Dioxygen serves as both oxidant and reactant.
W. Kong, B. Li, X. Xu, Q. Song, J. Org. Chem.,
2016, 81, 8436-8443.
Alcohols and aldehydes can be oxidized to the corresponding methyl esters by
reaction with methanol in the presence of crotononitrile as a hydrogen acceptor
using a catalyst combination of Ru(PPh3)3(CO)H2
with xantphos.
N. A. Owston, T. D. Nixon, A. J. Parker, M. K. Whittlesey, J. M. J. Williams,
Synthesis, 2009, 1459-1462.
A metal-free esterification of a broad range of alkynes with alcohols in the
presence of phenyliodine bis(trifluoroacetate) produces esters in good yields
via carbon triple bond cleavage. The transformation proceeds via
hydroxyethanones and ethanediones as intermediates and exhibits a broad
substrate scope and good functional group tolerance.
Q. Jiang, A. Zhao, B. Xu, J. Jia, X. Liu, C. Guo, J. Org. Chem., 2014,
79, 2709-2715.
Cobalt bis(acetylacetonate) mediates hydrogen atom transfer to a broad range of
functionalized alkenes. In situ oxidation of the resulting alkylradical
intermediates, followed by hydrolysis, provides expedient access to ketones and
esters. This method is compatible with a number of functional groups and
provides a mild and practical alternative to the Tamao-Fleming oxidation of
vinylsilanes and the Arndt-Eistert homologation.
X. Ma, S. B. Herzon, J. Org. Chem.,
2016, 81, 8673-8695.
A unique Au-allenylidene pathway enables an in situ formation of highly
unsaturated alkylidene ketenes from propargyl alcohol derivatives. A subsequent trapping with a broad
range of nucleophiles such as alcohols, phenols, water, amines, and sulfoximines
in the presence of an N-oxide provides α,β-unsaturated drug and natural
product derivatives.
X. Sun, X. Duan, N. Zheng, W. Song, Org. Lett., 2023, 25,
2798-2805.
Purification-controlled defluorinative esterification and
1,3-dietherification of (trifluoromethyl)alkenes with alcohols provide various
useful α-arylacrylates and 1,3-diethers in high yields. These catalyst-free
reactions offer simple operation, mild conditions, scalability, broad substrate
scope, and functional group tolerance.
H. Li, C. Zhu, J. Org. Chem., 2023, 88,
4134-4144.
A Ag2O-catalyzed reaction of carboxylic acids, ynol ethers, and
m-CPBA provides α-carbonyloxy esters via formation of three C-O bonds. The
protocol offers use of readily available starting materials and broad substrate
scope.
L. Zeng, H. Sajiki, S. Cui,
Org. Lett., 2019, 21, 6423-6426.
An efficient oxidation of various acetals, including open-chain acetals,
1,3-dioxanes and 1,3-dioxalanes, with molecular oxygen in the presence of
catalytic amounts of N-hydroxyphthalimide (NHPI) and Co(OAc)2
as co-catalyst gave esters.
B. Karimi, J. Rajabi, Synthesis, 2003, 2373-2377.
In the presence of hydrogen peroxide and trimethylsilyl chloride, thiocarbonyls
desulfurize to the corresponding carbonyls in short reaction times with no side
reactions and excellent selectivity. This process is a safe, operationally
simple, and environmentally benign alternative for the desulfurization of
thiocarbonyls.
K. Bahrami, M. M. Khodaei, M. Tajik, Synthesis, 2010,
4282-4286.
The oxidation of malononitrile derivatives with peracid in methanol proceeds
with loss of the cyano groups to yield methyl esters in high yield. The method
was applied to a variety of malononitrile derivatives, some of which were
prepared by Pd- or Ir-catalyzed asymmetric allylic substitution.
S. Förster, O. Tverskoy, G. Helmchen, Synlett, 2008,
2803-2806.
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.
In the presence of TBAI/TBHP, treatment of esters possessing a methylene carbon
α-to oxygen with benzylamines provides bis-esters rather than the expected
amides. Under these oxidative conditions, benzylamines generate less
nucleophilic carboxylates, which couple at sp3 C-H bonds of esters
and cyclic ethers to yield bis-acyl ketals and α-acyloxy ethers, respectively.
G. Majji, S. Rajamanickam, N. Khatun, S. K. Santra, B. K. Patel, J. Org. Chem.,
2015,
80, 3440-3446.
An efficient oxidation of cyclic acetals provided hydroxy alkyl esters in good
yields in the presence of MCPBA.
J. Y. Kim, H. Rhee, M. Kim, J. Korean Chem. Soc., 2002, 46,
479-483.
CrO3 is an efficient catalyst for benzylic oxidation with periodic
acid as the terminal oxidant in acetonitrile. Substituted electron-poor toluenes
and diarylmethanes were oxidized to the corresponding substituted benzoic acids
and ketones in excellent yields. Benzyl ethers such as isochroman and phthalan
were converted to 3,4-dihydroisocoumarin and phthalide in quantitative yields.
S. Yamazaki,
Org. Lett., 1999, 1, 2129-2132.