Categories: C-O Bond Formation > Synthesis of esters > Esterification, Transesterification, Acylation >
Acylations
Name Reactions
Recent Literature
Surprisingly, only a 0.05−2 mol % of DMAP can efficiently promote acylation of
alcohols with acid anhydrides under auxiliary base- and solvent-free conditions
to give the corresponding esters in high yields. Furthermore, the
recovery and reuse of commercially available polystyrene-supported DMAP was
achieved without
using any solvents.
A. Sakakura, K. Kawajiri, T. Ohkubo, Y. Kosugi, K. Ishihara, J. Am. Chem. Soc., 2007,
129, 14775-14779.
4-(N,N-Dimethylamino)pyridine hydrochloride (DMAP·HCl) was used as a
recyclable catalyst for the acylation of inert alcohols and phenols under
base-free conditions. The catalyst can be reused more than eight times without
loss in activity and works with various acylating reagents.
Z. Liu, Y. Liu, Q. Wang, Org. Lett., 2014,
16, 236-239.
Inexpensive phosphoric acid
(H3PO4) catalyzes a safe and simple acylation of alcohols with acid anhydrides.
In situ-generated diacylated mixed anhydrides are proposed as the active
species - acting as efficient
catalytic acyl transfer reagents. A
23 g scale synthesis of an ester was demonstrated.
H. Hayashi, S. Yasukochi, T. Sakamoto, M. Hatano, K. Ishihara, J. Org. Chem., 2021, 86,
5197-5212.
Vanadyl triflate efficiently catalyzes a nucleophilic acyl substitution of
anhydrides with a myriad array of alcohols, amines, and thiols in high yields
and high chemoselectivity. By using mixed-anhydride technique, oleate and
peptide syntheses can be achieved.
C.-T. Chen, J.-H. Kuo, C.-H. Li, N. B. Barhate, S.-W. Hon, T.-W. Li, S.-D. Chao,
C.-C. Liu, Y.-C. Li, I.-H. Chang, J.-S. Lin, C.-J. Liu, Y.-C. Chou, Org. Lett., 2001, 3,
3729-3732.
Various alcohols, thiols, phenols, and amines can be acetylated using acetic
anhydride in the presence of catalytic quantity of silver triflate. The method
proceeds under mild conditions, does not involve cumbersome workup, and the
resulting products are obtained in high yields within a reasonable time.
R. Das, D. Chakraborty, Synthesis, 2011,
1621-1625.
Phosphomolybdic acid (PMA) is a simple and efficient catalyst for the
acetylation of structurally diverse alcohols, phenols, and amines. Acetylation
reactions with acetic anhydride proceed in excellent yield in the presence of a
catalytic amount of PMA at ambient temperature within a relatively short
reaction time under solvent-free conditions.
S. T. Kadam, S. S. Kim, Synthesis, 2008,
267-268.
Acylation of alcohols, thiols, and sugars were studied with a variety of
Lewis acids, and it was found that Cu(OTf)2 was very efficient in
catalyzing the reaction under mild conditions in CH2Cl2.
K. L. Chandra, P. Saravan, R. K. Singh, V. K. Singh, Tetrahedron, 2002, 58,
1369-1374.
Copper(II) tetrafluoroborate efficiently catalyzes acetylation of
structurally diverse phenols, alcohols, thiols, and amines with
stoichiometric amounts of Ac2O under solvent-free conditions at
room temperature. Acid-sensitive alcohols are smoothly acetylated without
competitive side reactions.
A. K. Chakraborti, R. Gulhane, Shivani, Synthesis, 2004,
111-115.
Various alcohols, phenols, amines and thiols
may easily be converted into acetate derivatives by treatment
with acetic anhydride in the presence of
acetonyltriphenylphosphonium bromide in good yields at room
temperature. With the same precatalyst, both aliphatic and aromatic aldehydes
can be transformed into the corresponding gem-diacetates under reflux
conditions.
A. T. Khan, L. H. Choudry, S. Ghosh, Eur. J. Org. Chem., 2005,
2782-2787.
Benzylidene 1,1-diacetate is a sustainable and efficient acyl donor for
enzymatic acylation of chiral and nonchiral alcohols. Especially, unsaturated
acetates can be converted without E/Z isomerization. The acyl
donor can be recreated and reused. A dynamic kinetic resolution (DKR) protocol
results in chiral acetates in high yields and very high enantiomeric excesses.
D. Koszelewski, A. Brodzka, A. Madej, D. Trzepizur, R. Ostaszewski, J. Org. Chem., 2021, 86,
6331-6342.
A very fast acylation of alcohols with benzoyl chloride in the presence of TMEDA
at -78°C afforded the corresponding benzoates in excellent yields.
T. Sano, Synthesis,
1999,
1141-1144.
The data of a study on mixed aliphatic-aromatic anhydrides suggest that
during the Yamaguchi esterification reaction, a symmetric aliphatic
anhydride is produced in situ, which upon reaction with an alcohol yields
the ester. A one-pot procedure for the regioselective synthesis of aliphatic
esters is described using benzoyl or p-toluoyl chloride instead of
the sterically hindered Yamaguchi acid chloride.
I. Dhimitruka, J. SantaLucia, Org. Lett.,
2006, 8, 47-50.
The use of diacyl disulfide as an acylation reagent enables an efficient ester
formation under DMAP catalysis. A site-selective acylation of phenolic and
primary aliphatic hydroxyl groups greatly expands the scope of protecting group
chemistry. Diacyl disulfides offer excellent moisture tolerance, high efficiency,
and potential in synthetic chemistry and biologically meaningful natural product
modification.
H.-X. Liu, Y.-Q. Dang, Y.-F. Yuan, Z.-F. Xu, S.-X. Qiu, H.-B. Tan, Org. Lett.,
2016, 18, 5584-5587.
A general, transition-metal-free, and operationally simple method for
esterification of amides proceeds under
exceedingly mild conditions via a highly selective cleavage of N-C(O) bonds. The reaction
offers broad
substrate scope and excellent functional group tolerance.
G. Li, P. Lei, M. Szostak, Org. Lett.,
2018, 20, 5622-5625.
Carbonylimidazole derivatives are highly active acylation reagents for
esterification and amidation in the presence of pyridinium salts as catalysts.
These reactions are thought to involve both Brønsted acid and nucleophilic
catalysis. This mode of activation has been applied to the synthesis of
difficult to access oxazolidinones, as well as esters and amides.
S. T. Heller, T. Fu, R. Sarpong, Org. Lett., 2012,
14, 1970-1973.
A convenient procedure allows the synthesis of esters and thioesters from the
corresponding carboxylic acid using TFFH as the coupling reagent. The
preparation of N-acyl-dithiocarbamates from carboxylic acids and
1,3-thiazolidine-2-thione is also described.
M. Pittelkow, F. S. Kamounah, U. Boas, B. Pedersen, J. B. Christensen, Synthesis,
2004, 2485-2492.
M. Bassetti, A. D'Annibale, A. Fanfoni, F. Minissi, Org. Lett., 2005, 7, 1805-1808.
Er(OTf)3 is an efficient Lewis acid catalyst in a mild
deprotection of benzylidene derivatives. A simultaneous cleavage of
benzylidene acetals and peracetylation of the substrates is obtained in
quantitative yields in acetic anhydride as solvent.
A. Procopio, R. Dalpozzo, A. De Nino, L. Maiuolo, M. Nardi, G. Romeo, Org. Biomol. Chem., 2005, 3, 4129-4133.
In a simple protocol for the synthesis of α-diarylacetic esters from benzoins,
in situ generated acetals assist rapid 1,2-aryl migration in a stereospecific
manner, paving the way to make enantioenriched α-diarylacetic esters from easily
accessible enantiopure benzoins.
R. B. Kothapalli, R. Niddana, R. Balmurugan, Org. Lett., 2014,
16, 1278-1281.
Stereodefined enol derivatives of aldehydes are prepared from terminal alkynes
through Cp2ZrCl2-catalyzed methylalumination and
subsequent oxygenation with peroxyzinc species and electrophilic trapping with
carboxylic anydrides. The tandem carbometalation/oxygenation tolerates free and
protected alcohols, heterocycles, olefins, and nitriles.
J. R. DeBergh, K. M. Spivey, J. M. Ready, J. Am. Chem. Soc., 2008,
130, 7828-7829.
Lipase-catalyzed enantioselective esterification of β-azido alcohols in
combination with ruthenium-catalyzed alcohol isomerization enables a successful
dynamic kinetic resolution (DKR) of racemic β-azido alcohols to the
corresponding enantiomerically pure acetates.
O. Pàmies, J.-E. Bäckvall, J. Org. Chem., 2001,
66, 4022-4025.
