56053-84-0Relevant academic research and scientific papers
β-Nitroacrylates as Starting Materials of Thiophene-2-Carboxylates Under Continuous Flow Conditions
Chiurchiù, Elena,Patehebieke, Yeersen,Gabrielli, Serena,Ballini, Roberto,Palmieri, Alessandro
, p. 2042 - 2047 (2019/03/13)
We report herein a general and efficient continuous flow-based protocol for synthesizing thiophene-2-carboxylates starting from ketal-functionalized β-nitroacrylates. The protocol involves (i) a promoter-free conjugate addition of thioacetic acid to β-nitroacrylates, (ii) a base-induced elimination of nitrous acid, and (iii) a final acid-promoted domino cyclization-aromatization process to afford the title targets. Thanks to the means of the flow chemistry and the use of solid supported systems, the three steps were combined in a whole flow chemical process, by which the products were isolated in good to excellent overall yields (38–88%). (Figure presented.).
A Straightforward Conversion of Activated Amides and Haloalkanes into Esters under Transition-Metal-Free Cs 2 CO 3 /DMAP Conditions
Chen, Liuqing,Gu, Ying,Jian, Junsheng,Liu, Yueping,Miao, Liqiong,Wang, Zijia,Zeng, Zhuo
, p. 4078 - 4084 (2019/10/28)
The esterification of activated amides, N -acylsaccharins, under transition-metal-free conditions with good functional group tolerance has been developed, resulting in C-N cleavage leading to efficient synthesis of a variety of esters in moderate to good yields. This work demonstrates that esterification may proceed by using simple N -acylsaccharins, haloalkanes, and Cs 2 CO 3 as oxygen source.
Synthesis of Esters from Stable and Convenient Sulfoxonium Precursors under Catalyst- And Additive-Free Conditions
Wu, Xiao-Feng,Yuan, Yang
, p. 1820 - 1824 (2019/09/09)
A convenient and efficient procedure for the construction of esters from stable sulfoxonium ylides and alcohols has been developed. This protocol presents a broad substrate scope and good yields of the desired esters can be isolated. Notably, no catalyst, oxidant, base or any other additive is required.
Aerobic oxidative esterification and thioesterification of aldehydes using dibromoisocyanuric acid under mild conditions: No metal catalysts required
Kwon, Young-Do,La, Minh Thanh,Kim, Hee-Kwon
, p. 10833 - 10841 (2018/07/05)
A practical direct method for the direct preparation of esters and thioesters from aldehydes is described. Esters and thioesters were synthesized by oxidative esterification and thioesterification via in situ generated acyl bromide intermediates, which were used to react with various alcohols and thiols. The esterification and thioesterification were readily performed in the presence of dibromoisocyanuric acid in dichloromethane, without any metal catalysts and under mild conditions. By using this reaction protocol, various esters and thioesters were prepared in high yields. This effective method offers a promising approach for the facile esterification and thioesterification of aldehydes.
Practical: In situ -generation of phosphinite ligands for palladium-catalyzed carbonylation of (hetero)aryl bromides forming esters
Wang, Lin,Neumann, Helfried,Spannenberg, Anke,Beller, Matthias
supporting information, p. 7469 - 7472 (2017/07/12)
An effective method for alkoxycarbonylation of (hetero)aryl bromides is developed in the presence of in situ-generated phosphinite ligands tBu2POR (R = nBu, nPr, Et or Me). For this purpose commercially available tBu2PCl was used as the pre-ligand in the presence of different alcohols. For the first time cross coupling reactions with two alcohols-one generating the ligand, the other used as substrate-were developed. Through this method, ligand optimization can be performed in a more efficient manner and the desired products could be obtained with good yields and selectivity.
Synthetic method of an ester compound
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Paragraph 0069; 0070; 0071, (2017/02/02)
The invention discloses a synthetic method of an ester compound and belongs to the technical field of organic synthesis. The synthetic method includes the steps of: dissolving an aldehyde compound (1) and a halogenated hydrocarbon compound (2) in a solvent, adding an oxidant and a catalyst, and performing a reaction at 60-100 DEG C to obtain the target product ester compound (3). A reaction equation of the synthetic method is represented as follows. The method, compared with the prior art, has the following advantages: 1) the raw materials are easy to obtain and are low in cost; 2) the reaction conditions are mild, operations are simple, and reaction time is short; and 3) a substrate has wide available range and can be used for synthesis of various ester compounds.
Ligand free palladium catalyzed decarboxylative cross-coupling of aryl halides with oxalate monoester salts
Li, Yan,Chen, Huan-Huan,Wang, Chu-Fei,Xu, Xiao-Lan,Feng, Yi-Si
, p. 5796 - 5799 (2012/10/29)
Ligand free Pd-catalyzed decarboxylative cross-coupling of potassium oxalate monoester and derivatives with aryl iodides and bromides is described. Functionalized aromatic esters can be efficiently synthesized via this method with only 1.0 mol % Pd(OAc)2 catalyst without any phosphine ligand. This method illustrates an inexpensive and operationally simple method for the preparation of aromatic esters and acids, which is especially beneficial for a large scale synthesis.
Efficient carbonylation of aryl and heteroaryl bromides under atmospheric pressure of CO
Yang, Weizhun,Han, Wei,Zhang, Weidong,Shan, Lei,Sun, Jiansong
supporting information; experimental part, p. 2253 - 2255 (2011/10/19)
In the presence of Et and n-BuOH, efficient alkoxycarbonylation of (hetero)aromatic bromides was achieved under atmospheric pressure of carbon monoxide with in situ generated palladium/rac-BINAP as catalyst. Georg Thieme Verlag Stuttgart - New York.
Protic acid immobilized on solid support as an extremely efficient recyclable catalyst system for a direct and atom economical esterification of carboxylic acids with alcohols
Chakraborti, Asit K.,Singh, Bavneet,Chankeshwara, Sunay V.,Patel, Alpesh R.
supporting information; experimental part, p. 5967 - 5974 (2009/12/24)
(Chemical Equation Presented) A convenient and clean procedure of esterification is reported by direct condensation of equimolar amounts of carboxylic acids with alcohols catalyzed by an easy to prepare catalyst system of perchloric acid immobilized on silica gel (HClO4-SiO2). The direct condensation of aryl, heteroaryl, styryl, aryl alkyl, alkyl, cycloalkyl, and long-chain aliphatic carboxylic acids with primary/secondary alkyl/cycloalkyl, allyl, propargyl, and long-chain aliphatic alcohols has been achieved to afford the corresponding esters in excellent yields. Chiral alcohol and N-t-Boc protected chiral amino acid also resulted in ester formation with the representative carboxylic acid or alcohol without competitive N-t-Boc deprotection and detrimental effect on the optical purity of the product demonstrating the mildness and chemoselectivity of the procedure. The esters of long-chain (>C10) acids and alcohols are obtained in high yields. The catalyst is recovered and recycled without significant loss of activity. The industrial application of the esterification process is demonstrated by the synthesis of prodrugs of ibuprofen and a few commercial flavoring agents. Other protic acids such as H2SO4, HBr, TfOH, HBF4, and TFA that were adsorbed on silica gel were less effective compared to HClO4-SiO2 following the order HClO4-SiO 2 ? H2SO4-SiO2 > HBr-SiO 2 > TfOH-SiO2 ? HBF4-SiO2 ≈ TFA-SiO2. When HClO4 was immobilized on other solid supports the catalytic efficiency followed the order HClO4-SiO 2 > HClO4-K10 > HClO4-Al 2O3 (neutral) > HClO4-Al2O 3 (acidic) > HClO4-Al2O3 (basic).
New cyclopentadienyl, indenyl or fluorenyl substituted phosphine compounds and their use in catalytic reactions
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Page/Page column 64; 65, (2008/06/13)
The invention is directed to a phosphine compound represented by general formula (1) wherein R' and R" independently are selected from alkyl, cycloalkyl and 2-furyl radicals, or R' and R" are joined together to form with the phosphorous atom a carbon-phosphorous monocycle comprising at least 3 carbon atoms or a carbon-phosphorous bicycle; the alkyl radicals, cycloalkyl radicals, and carbon-phosphorous monocycle being unsubstituted or substituted by at least one radical selected from the group of alkyl, cycloalkyl, aryl, alkoxy, and aryloxy radicals; Cps is a partially substituted or completely substituted cyclopentadien-1-yl group, including substitutions resulting in a fused ring system, and wherein a substitution at the 1-position of the cyclopentadien-1-yl group is mandatory when the cyclopentadien-1-yl group is not part of a fused ring system or is part of an indenyl group. Also claimed is the use of these phosphines as ligands in catalytic reactions and the preparation of these phosphines.
