Categories: C-O Bond Formation > Synthesis of esters > Esterification, Transesterification, Acylation >
Transesterifications
Recent Literature
A N-heterocyclic carbene (NHC) catalyzed transformylation of 1°, 2°, and 3°
alcohols in the presence of methyl formate as the formyl transfer reagent
provides a broad range of formates in good yields. The reaction employs low
catalyst loadings, is insensitive to common nitrogen and oxygen protecting
groups and can be achieved in the presence of a number of heterocycles.
J. E. M. Fernando, A. Levens, D. Moock, D. W. Lupton, Synthesis, 2017,
49, 3505-3510.
In the presence of a Zn-cluster catalyst, alcohols are efficiently converted
to the corresponding acetates in very good yields just by refluxing in EtOAc. The mild reaction
conditions enabled a selective acetylation of various functionalized alcohols
even in the presence of highly nucleophilic aliphatic amino groups.
T. Iwasaki, Y. Maegawa, Y. Hayashi, T. Ohshima, K. Mashima, Synlett, 2009,
1659-1663.
Primary and secondary alcohols react with vinyl or isopropenyl acetate at
room temperature in the presence of Y5(OiPr)13O as
catalyst to give the corresponding esters. In selected cases, the yttrium
catalyst promotes a selective O-acylation of amino alcohols without the
formation of the amide.
M.-H. Lin, T. V. RajanBabu,
Org. Lett., 2000, 2, 997-1000.
An efficient Na2CO3-catalyzed O-acylation of
phenols with alkenyl carboxylates as acyl reagents in MeCN provides aryl
carboxylates in very good yields.
X.-Y. Zhou, X. Chen, Synlett, 2018, 29,
2321-2325.
Catalytic amounts of alkylidene derivatives of N-heterocyclic carbenes
promote transesterification reactions. Because of their strong Brønsted/Lewis
basicity, these organocatalysts can enhance the nucleophilicity of alcohols for
acylation reactions with carboxylic esters.
M. Blümel, J.-M. Noy, D. Enders, M. H. Stenzel, T. V. Nguyen, Org. Lett.,
2016, 18, 2208-2211.
A catalytic transesterification is promoted by a tetranuclear zinc cluster. The
mild reaction conditions enabled the reactions of various functionalized
substrates to proceed in very good yield. A large-scale reaction under
solvent-free conditions offers high environmental and economical advantages.
T. Iwasaki, Y. Maegawa, Y. Hayashi, T. Ohshima, K. Mashima, J. Org. Chem., 2008,
73, 5147-5150.
Silica chloride is an efficient catalyst for esterification of carboxylic
acids with alcohols as well as for transesterification of esters by both
alcoholysis and acidolysis.
K. V. N. S. Srinivas, I. Mahender, B. Das, Synthesis, 2003,
2479-2482.
K. V. N. S. Srinivas, I. Mahender, B. Das, Synthesis, 2003, 2390-2394.
Sc(OTf)3 catalyses a direct transesterification of carboxylic esters
in boiling alcohols. Methyl, ethyl, isopropyl, and allyl esters were prepared
from various substrates in high yields. The application of microwave irradiation
led to significantly reduced reaction times.
N. Remme, K. Koschek, C. Schneider, Synlett, 2007,
491-493.
K2HPO4 is an efficient catalyst for transesterifications
to produce methyl esters. Various functional groups are tolerated under the mild
reaction conditions.
T. Shinada, M. Hamada, K. Miyoshi, M. Higahino, T. Umezawa, Y. Ohfune, Synlett, 2010,
2141-2145.
A benzyne-mediated esterification of carboxylic acids and alcohols provides
products under mild conditions via a selective nucleophilic addition of
carboxylic acid to benzyne in the presence of alcohol followed by a
transesterification with alcohol. Benzyne can also be used to promote
lactonization and amidation reactions.
J. Zhao, J. Shi, Y. Li, Org. Lett., 2021, 23,
7274-7278.
A mild, functional group tolerant palladium-catalyzed carbonylation of aryl
chlorides using atmospheric pressure of carbon monoxide allows the preparation
of phenyl esters, alkyl esters and carboxylic acids. Phenyl esters are shown to
be useful acylating agents, delivering libraries of carbonyl derivatives,
including alkyl, allyl and thioesters, under very mild conditions.
D. A. Watson, X. Fan, S. L. Buchwald, J. Org. Chem., 2008,
73, 7096-7101.
Various alcohols, amines and N-hydroxylamines gave corresponding
formylated adducts in high yields by treatment with 2,2,2-trifluoroethyl
formate (TFEF). Chemoselective formylation of a primary amine could be readily
achieved in the presence of an unprotected primary alcohol.
D. R. Hill, C.-N. Hsiao, R. Kurukulasuriya, S. Wittenberger, Org. Lett.,
2002, 4, 111-113.
Transesterification/acylation reactions of secondary alcohols are
efficiently catalyzed by N-Heterocyclic carbenes (NHC) at room
temperature.
R. Singh, R. M. Kissling, M.-A. Letellier, S. P. Nolan, J. Org. Chem., 2004,
69, 209-212.
A carbene-catalyzed reaction enables a dynamic kinetic resolution of
α,α-disubstituted carboxylic esters with up to 99:1 er and 99% yield.
X. Chen, J. Z. M. Fong, J. Xu, C. Mou, Y. Lu, S. Yang, B.-A. Song, Y. R. Chi, J. Am. Chem. Soc., 2016,
138, 7212-7215.
In the presence of sodium acetate, the reaction between 2,2,6-trimethyl-4H-1,3-dioxin-4-one
and secondary or tertiary alcohols or primary or secondary amines could be
carried out in refluxing tetrahydrofuran. Under these much milder conditions,
side products were avoided, and β-keto esters and β-ketoamides were normally
obtained in quantitative yields.
V. Sridharan, M. Ruiz, J. C. Menéndez, Synthesis, 2010,
1053-1057.
Iodine catalyses a facile transesterification of β-ketoesters.
S. P. Chavan, R. R. Kale, K. Shivasankar, S. I. Chandake, S. B. Benjamin, Synthesis, 2003, 2695-2698.