5798-76-5Relevant academic research and scientific papers
Conversion of esters to thioesters under mild conditions
Shi, Yijun,Liu, Xuejing,Cao, Han,Bie, Fusheng,Han, Ying,Yan, Peng,Szostak, Roman,Szostak, Michal,Liu, Chengwei
supporting information, p. 2991 - 2996 (2021/04/14)
We report conversion of esters to thioestersviaselective C-O bond cleavage/weak C-S bond formation under transition-metal-free conditions. The method is notable for a general and practical transition-metal-free system, broad substrate scope and excellent functional group tolerance. The strategy was successfully deployed in late-stage thioesterification, site-selective cross-coupling/thioesterification/decarbonylation and easy-to-handle gram scale thioesterification. Selectivity and computational studies were performed to gain insight into the formation of weak C-S bonds by C-O bond cleavage, which contrasts with the traditional trend of nucleophilic additions to carboxylic acid derivatives.
Acetyl nitrate mediated conversion of methyl ketones to diverse carboxylic acid derivatives
Bernard, Josephine,Capilato, Joseph N.,Hoy, Erik P.,Mattiucci, Joseph,Pellegrinelli, Peter J.,Perez, Lark J.,Philippi, Shane,Schnorbus, Logan
, p. 5298 - 5302 (2021/06/30)
The development of a novel acetyl nitrate mediated oxidative conversion of methyl ketones to carboxylic acid derivatives is described. By analogy to the haloform reaction and supported by experimental and computational investigation we propose a mechanism for this transformation.
Mechanically induced solvent-free esterification method at room temperature
Zheng, Lei,Sun, Chen,Xu, Wenhao,Dushkin, Alexandr V.,Polyakov, Nikolay,Su, Weike,Yu, Jingbo
, p. 5080 - 5085 (2021/02/05)
Herein, we describe two novel strategies for the synthesis of esters, as achieved under high-speed ball-milling (HSBM) conditions at room temperature. In the presence of I2 and KH2PO2, the reactions afford the desired esterification derivatives in 45% to 91% yields within 20 min of grinding. Meanwhile, using KI and P(OEt)3, esterification products can be obtained in 24% to 85% yields after 60 min of grinding. In addition, the I2/KH2PO2 protocol was successfully extended to the late-stage diversification of natural products showing the robustness of this useful approach. Further application of this method in the synthesis of inositol nicotinate was also discussed. This journal is
Cu(II)-silsesquioxanes as efficient precatalysts for Chan-Evans-Lam coupling
Astakhov, G. S.,Bantreil, X.,Bilyachenko, A. N.,Dorovatovskii, P. V.,Khrustalev, V. N.,Lamaty, F.,Levitsky, M. M.,Shubina, E. S.,Zubavichus, Y. V.
, (2019/11/28)
Two cage copper(II)silsesquioxanes, namely, tricopper complex (PhSiO1.5)8(CuO)3(TMEDA)2*(MeCN)3 Cu-1 and hexacopper complex (MeSiO1,5)12(CuO)6(Py)6*TMEDA Cu
Method for preparing diaryl ester compound through efficient catalysis of pyridine palladium
-
Paragraph 0016-0020; 0046-0050, (2020/12/31)
The invention discloses a method for preparing a diaryl ester compound through efficient catalysis of pyridine palladium. The method is used for high-efficiency high-yield preparation of the diaryl ester compound under mild conditions by taking a phenol compound, an iodobenzene compound and carbon monoxide as raw materials, triethylamine as alkali and pyridine palladium as a catalyst. The method provided by the invention has the advantages of less usage amount of the palladium catalyst, high catalytic activity of the palladium catalyst, stability of the palladium catalyst to air, simple operation, short reaction time and high atom economy, opens up a low-cost, green and efficient way for preparation of diaryl ester compounds, and has broad application prospects.
Design and Bioevaluation of Novel Hydrazide-Hydrazones Derived from 4-Acetyl-N-Substituted Benzenesulfonamide
?ztürk, M.,Bozkurt, E.,Iyido?an, A. Karakü?ük,Oru?-Emre, E. E.,S?cak, Y.
, p. 702 - 714 (2020/10/29)
Abstract: In this research, a series of hydrazine-hydrazone derivatives (Ia–g), (IIa–h) were synthesized to discover new antioxidant and anticholinesterase agents. The structures of synthesized compounds were characterized by spectroscopic data using UV, IR, 1H, 13C NMR, mass spectroscopy, and elemental analysis. The bio-evaluation of the synthesized compounds (Ia–g), (IIa–h) were evaluated according to in vitro activity assays. The results of β-carotene/linoleic acid assay showed that among the synthesized compounds, the (Ib), (Ie), (IIb–IIe), and (IIh) compound exhibited higher activity for the lipid peroxidation inhibitory activity. In the DPPH free scavenging activity and the cation radical scavenging activity in ABTS?+ activity, compound (IIb) was found to be more active. In the CUPRAC reduced power assay, the A0.5 values of all synthesized compounds were better than α-TOC. In AChE assay, compound (IIb) exhibited the most activity with IC50 = 11.12 ± 0.74 μM, while the compounds (Ib–g) and (IIb–h), exhibited excellent activity than the positive standard galantamine (IC50 = 46.06 ± 0.10 μM) in the BChE assay.
An alternative route for boron phenoxide preparation from arylboronic acid and its application for C[sbnd]O bond formation
Joo, Seong-Ryu,Kim, Seung-Hoi,Lim, In-Kyun
, (2020/08/06)
An efficient synthetic route to benzyl phenyl ether preparation has been successfully developed via a one-pot synthetic protocol utilizing a combination of arylboronic acids, hydrogen peroxide (H2O2), and benzyl halides. The whole procedure consists of two consecutive reactions, formation of boron phenoxide from arylboronic acids and its nucleophilic attack. A simple operation under mild conditions such as room-temperature ionic liquid (choline hydroxide), aerobic environment, and absence of metal- and base-catalysts has been employed. Expansion to utilize benzyl surrogates was also successfully accomplished.
Palladium-catalyzed aryloxy- and alkoxycarbonylation of aromatic iodides in γ-valerolactone as bio-based solvent
Tukacs, József M.,Marton, Bálint,Albert, Eszter,Tóth, Imre,Mika, László T.
, (2020/08/11)
Fossil-based solvents and triethylamine as a toxic and volatile base were successfully replaced with γ-valerolactone as a non-volatile solvent and K2CO3 as inorganic base in the alkoxy- and aryloxycarbonylation of aryl iodides using phosphine-free Pd catalyst systems. By this, the traditional systems were not simply replaced but also significantly improved. In the study, the effects of different reaction parameters, i.e. the use of several other solvents, the temperature, the carbon monoxide pressure, the base and the catalyst concentrations, were evaluated in details on the efficiency of the carbonylations. To gather some information on the mechanism of these reactions, the effects of the electronic parameters (σ) of various aromatic substituents of the aryl iodides as well as the influence of para-substitution of phenol were investigated on the activity. For a comparison, the aryl-substituted aryl iodides were also reacted with methanol and aryl iodide was also alkoxycarbonylated using several different lower alcohols. From the observed correlations between the electronic parameters of the aromatic substituents and the rates, it appears that the rate determining step is the oxidative addition of Ar–I to Pd0, provided that sufficient amounts of nucleophiles are present for the ester formation. If this is not the case, the rate of nucleophile attack might determine the overall rate.
Amidation and esterification of carboxylic acids with amines and phenols by N,N′-diisopropylcarbodiimide: A new approach for amide and ester bond formation in water
Fattahi, Nadia,Ayubi, Morteza,Ramazani, Ali
, p. 4351 - 4356 (2018/07/13)
The present study reports the successful synthesis of two important and abundant functional groups “ester and amide” by N,N′-diisopropylcarbodiimide (DIC) in water as a green solvent. A wide range of substrates could be employed with high functional group tolerance. The products were obtained in high yields after short reaction times. This method provides an efficient, economic, simple and very mild protocol for ester and amide bond formation in aqueous media. In addition, this work not only may lead to environmentally benign systems but also will provide a new aspect of organic chemistry in water.
Rhodium-catalysed aryloxycarbonylation of iodo-aromatics by 4-substituted phenols with carbon monoxide or paraformaldehyde
Seni, Anas Abu,Kollár, László,Mika, László T.,Pongrácz, Péter
, p. 67 - 73 (2018/08/06)
Rhodium-catalysed phenoxycarbonylation of aryl iodides were carried out under carbon-monoxide atmosphere and in the absence of CO, using paraformaldehyde as an alternative surrogate for carbonylation reactions. Both strategies proved to be efficient for the synthesis of the corresponding phenyl esters. High pressure reactions provided the ester products with good selectivity, however lower activity was achieved compared to palladium containing systems. Using paraformaldehyde as carbon-monoxide source special reaction conditions are required, thus dramatic changes observed during optimisation reactions. Using in situ generated Rh-diphosphine catalyst systems, remarkable influence of ligand structure and solvent composition was observed on the activity and chemoselectivity. The substrate scope and the substituent effect were also investigated.
