- Iron(III)-catalyzed direct synthesis of diphenylmethyl esters from 2-diphenylmethoxypyridine
-
A highly efficient method has been developed for the synthesis of diphenylmethyl (DPM) esters from 2-diphenylmethoxypyridine. Various carboxylic acids readily reacted with 2-diphenylmethoxypyridine in the presence of FeCl3 as a catalyst to provide the desired DPM esters with high yields. The procedure is facile and enables effective synthesis of a variety of esters for the protection of carboxylic acids.
- Tran, Van Hieu,La, Minh Thanh,Kim, Hee-Kwon
-
p. 2379 - 2387
(2019/07/03)
-
- Facile synthesis of diphenylmethyl esters from 2-diphenylmethoxypyridine using catalytic boron trifluoride·diethyl etherate
-
A practical method for the direct preparation of diphenylmethyl (DPM) esters from 2-diphenylmethoxypyridine is described. The reaction was readily performed in the presence of a catalytic amount of boron trifluoride-diethyl etherate at room temperature. Using this reaction protocol, various carboxylic acids were converted to DPM esters with high yields. This method is highly effective for the protection of carboxylic acids and the synthesis of DPM esters, and offers a promising approach for facile esterification of a variety of carboxylic acids.
- La, Minh Thanh,Kim, Hee-Kwon
-
p. 1855 - 1859
(2018/04/11)
-
- Sulfonated nanohydroxyapatite functionalized with 2-aminoethyl dihydrogen phosphate (HAP@AEPH2-SO3H) as a reusable solid acid for direct esterification of carboxylic acids with alcohols
-
Sulfonated nanohydroxyapatite functionalized with 2-aminoethyl dihydrogen phosphate (HAP@AEPH2-SO3H) efficiently catalyzed direct esterification of carboxylic acids and alcohols with high selectivity toward the formation of esters in good to excellent yields. Our results clearly show that HAP@AEPH2-SO3H can be easily recovered by simple filtration and reused for subsequent five runs without any significant impact on yields of products. The main advantage of this methodology is easy and ecofriendly catalyst preparation, easy catalyst separation, practical simplicity, safe reaction conditions, recyclable catalyst and high products yields.
- Siavashi, Narges Yousefi,Akhlaghinia, Batool,Zarghani, Monireh
-
p. 5789 - 5806
(2016/06/01)
-
- Synthesis of esters by in situ formation and trapping of diazoalkanes
-
A general method has been developed for the in situ formation and trapping of diazoalkanes by carboxylic acids to form esters. The method is applicable to a large variety of carboxylic acids using diazo compounds that are formed from the hydrazones of benzaldehydes and aryl ketones. In situ reaction monitoring with IR spectroscopy (ReactIR) was used to demonstrate that slow addition of the hydrazone to a mixture of oxidant and carboxylic acid avoids the buildup of the diazo compound. This method enables the safe preparation of esters from simple precursors without isolation of diazo compounds.
- Squitieri, Richard A.,Shearn-Nance, Galen P.,Hein, Jason E.,Shaw, Jared T.
-
p. 5278 - 5284
(2016/07/14)
-
- The Reaction between Acyl Halides and Alcohols: Alkyl Halide vs. Ester Formation
-
In the reaction between an acyl halide and an alcohol the thermodynamically favoured products are the free carboxylic acid and the alkyl halide.The initial reaction is, generally, the formation of an ester and HHal.When the alcohol is very prone to yield an alkyl cation upon protonation by HHal, formed H2O exhibited a superior reactivity and competed successfully with the alcohol for the acyl halide making, therefore, ester formation practically confined to a triggering role.But, in those cases where the cation is less easily formed, ester formation was favoured and, consequently, became the necessary elementary step towards alkyl halide formation.Tis final product, on the other hand, might be extremely slow to form in an SN2 reaction between the protonated ester function and the halide ion.In these instances, therefore, as well as in the cases when a basic solvent competes for the proton of HHal, the ester is the final product.A notable exception of the situation above outlined, is given by α-hydroxy-α-phenylbenzeneacetic acid (2y), which appears to undergo direct chlorine-hydroxyl interchange through a quaternary intermediate (E), in the end collapsing to α-chloro-α-phenyl-benzeneacetic acid (4y).Different systems were compared using CH2Cl2 as a solvent under strictly similar conditions.Some 28 different substrates were tested for reaction with AcCl (1a), whereas the action of eight acyl halides (a) against (RS)-α-methylbenzenemethanol (2n) and α-phenylbenzenemethanol (2p), as well as the effect of five different solvents on the reaction between two alcohols (2p and 2-methyl-2-propanol, 2c) with 1a, were observed.
- Strazzolini, Paolo,Giumanini, Angelo G.,Verardo, Giancarlo
-
p. 217 - 254
(2007/10/02)
-
- Linear Free Energy ortho-Correlations in the Thiophene Series. Part IX (1). Kinetics of Esterification with Diazodiphenylmethane of Some 3-, 4- and 5-Substituted Thiophene-2-carboxylic Acids in Methanol
-
The rate constants for the esterification of some 3-, 4- and 5-substituted thiophene-2-carboxylic acids with diazodiphenylmethane in methanol at 25 deg C have been measured.The reactivity of some para- and ortho-substituted benzoic acids has also been det
- Noto, Renato,Buscemi, Silvestre,Consiglio, Giovanni,Spinelli, Domenico
-
p. 735 - 738
(2007/10/02)
-