959-22-8Relevant articles and documents
Copper-mediated simple and direct aerobic oxidative esterification of arylacetonitriles with alcohols/phenols
Dong, Jianyu,Chen, Xiuling,Ji, Fangyan,Liu, Lixin,Su, Lebin,Mo, Min,Tang, Jian-Sheng,Zhou, Yongbo
, (2020/10/20)
A simple and direct aerobic oxidative esterification reaction of arylacetonitriles with alcohols/phenols is achieved in the presence of a copper salt and molecular oxygen, which produces a broad range of aryl carboxylic acid esters in good to high yields. Copper salt plays multiple roles in the transformation, which allows the oxygenation of C-H bond, cleavage of inert C-C bond, and formation of C-O bond in one pot without the assistance of any of the acids, bases, ligands, and so on. The reaction provides a simple, direct, and efficient protocol towards functionalized esters, especially aryl benzoates, from readily available starting materials.
Carboxylic Acid Deoxyfluorination and One-Pot Amide Bond Formation Using Pentafluoropyridine (PFP)
Brittain, William D. G.,Cobb, Steven L.
, p. 5793 - 5798 (2021/08/01)
This work describes the application of pentafluoropyridine (PFP), a cheap commercially available reagent, in the deoxyfluorination of carboxylic acids to acyl fluorides. The acyl fluorides can be formed from a range of acids under mild conditions. We also demonstrate that PFP can be utilized in a one-pot amide bond formation via in situ generation of acyl fluorides. This one-pot deoxyfluorination amide bond-forming reaction gives ready access to amides in yields of ≤94%.
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
Substrate hydrophobicity and enzyme modifiers play a major role in the activity of lipase from: Thermomyces lanuginosus
Castro, Tarsila G.,Cavaco-Paulo, Artur,Noro, Jennifer,Silva, Carla
, p. 5913 - 5924 (2020/10/08)
Lipase from Thermomyces lanuginosus (TL) displays high affinity for long-chain substrates, such as triolein and other long-chain triacylglycerols. Aiming to broaden the substrate chain-length specificity, different aldehydes (naphthaldehyde, butyraldehyde, hexyl aldehyde and dodecyl aldehyde) and naphthyl isothiocyanate were grafted onto lipase TL through lysine coupling. The catalytic activity of the modified lipases was investigated by reaction with substrates differing in the aliphatic chain size (p-nitrophenyl benzoate, p-nitrophenyl acetate, p-nitrophenyl butyrate, p-nitrophenyl hexanoate, p-nitrophenyl octanoate, p-nitrophenyl laurate and p-nitrophenyl palmitate). The enzymes modified with aldehydes revealed higher activity than the enzymes modified with the isothiocyanate. The most notable results were achieved for lipase TL grafted with 4 units of a dodecyl chain (TL5), which revealed the highest activity against all the tested substrates, being 10-fold more active than the native enzyme for smaller substrates (acetate and butyrate chains) and 2-fold for longer substrates (laurate and palmitate chains). The kinetic parameters evaluated (Vmax, KM and kcat/KM) also confirmed the significant catalytic performance of TL5 compared to the native enzyme. The increase in activity revealed by the modified lipases was directly proportional to the size and hydrophobicity of the linkers' aliphatic chain. Small conformational changes, either on the enzyme's lid or on the cavity of the active site were suggested by molecular dynamics simulations, circular dichroism and fluorescence spectroscopy. Moreover, the grafting with aldehydes or with the isothiocyanate conferred higher thermostability to the lipase. The chemical surface modification developed efficiently improved the activity of lipase TL, broadening the substrate's chain-length specificity, increasing thereafter the substrate possibilities for industrial reactions. This journal is
Supramolecular Pd(II) complex of DPPF and dithiolate: An efficient catalyst for amino and phenoxycarbonylation using Co2(CO)8 as sustainable C1 source
Gaikwad, Vinayak V.,Mane, Pravin A.,Dey, Sandip,Patel, Divya,Bhanage, Bhalchandra M.
, (2019/11/28)
Highly active, efficient and robust “dppf ligated tetranuclear palladium dithiolate complex” was synthesized and applied as a catalyst for chemical fixation of carbon monoxide for the synthesis value added chemicals such as tertiary amide and aromatic esters. The synthesized catalyst was characterized using different analytical techniques such as elemental analysis, 1H and 31P NMR spectroscopy. The use of Co2(CO)8 as a cheap, less toxic and low melting solid surrogate are additional advantages over the current protocol. The catalyst showed superior activity towards the Amino (10?3 mol % catalyst) and Phenoxycarbonylation (10-2 mol % catalyst) and high TON (104 to 103) and TOF (103 to 102 h-1). The Betol and Lintrin (active drug molecules) were synthesized under an optimized reaction condition. The scalability of the current protocol has been demonstrated up-to the gram level.
Tropolonate salts as acyl-transfer catalysts under thermal and photochemical conditions: Reaction scope and mechanistic insights
Mai, Binh Khanh,Koenigs, Rene M.,Nguyen, Thanh Vinh,Lyons, Demelza J.M.,Empel, Claire,Pace, Domenic P.,Dinh, An H.
, p. 12596 - 12606 (2020/11/18)
Acyl-transfer catalysis is a frequently used tool to promote the formation of carboxylic acid derivatives, which are important synthetic precursors and target compounds in organic synthesis. However, there have been only a few structural motifs known to efficiently catalyze the acyl-transfer reaction. Herein, we introduce a different acyl-transfer catalytic paradigm based on the tropolone framework. We show that tropolonate salts, due to their strong nucleophilicity and photochemical activity, can promote the coupling reaction between alcohols and carboxylic acid anhydrides or chlorides to give products under thermal or blue light photochemical conditions. Kinetic studies and density functional theory calculations suggest interesting mechanistic insights for reactions promoted by this acyl-transfer catalytic system.
Selectivity in the photo-fries rearrangement of some aryl benzoates in green and sustainable media. Preparative and mechanistic studies
Siano, Gastón,Bonesi, Sergio M.,Crespi, Stefano,Mella, Mariella
, p. 4338 - 4352 (2019/05/01)
Irradiation of a series of p-substituted aryl benzoates under N2 atmosphere in homogeneous and micellar media was investigated by means of steady-state condition and of time-resolved spectroscopy. A notable selectivity in favor of the 2-hydroxybenzophenone derivatives was observed in micellar media. The benzophenone derivatives were the main photoproduct. On the other hand, in homogeneous media (cyclohexane, acetonitrile, and methanol) the observed product distribution was entirely different, viz. substituted 2-hydroxybenzophenones, p-substituted phenols, benzyl and benzoic acid were found. The binding constants in the surfactant were also measured and NOESY experiments showed that the aryl benzoates were located in the hydrophobic core of the micelle. Laser flash photolysis experiments led to the characterization of both p-substituted phenoxy radical and substituted 2-benzoylcyclohexadienone transients in homogeneous and micellar environment.
Practical and efficient synthesis of hydroxyaryl ketones catalyzed by HF@SiO2 under solvent-free condition
Paghandeh, Hossein,Saeidian, Hamid,Ghaffarzadeh, Mohammad
, p. 809 - 814 (2018/09/26)
A wide variety of hydroxyaryl ketones bearing different motifs was successfully synthesized with good yields and excellent selectivities in the presence of HF@SiO2 as an environmental friendly acid under solvent-free condition. Mild and green reaction conditions and excellent yields (50-91%) make this method an attractive method for the efficient synthesis of hydroxyaryl ketones. Fries rearrangement of phenyl benzoate in the presence of HF@SiO2 led to p-hydroxybenzophenone, while phenyl acetate in the same conditions produced o-hydroxyacetophenone as a single isomer.
Transition-Metal-Free Esterification of Amides via Selective N-C Cleavage under Mild Conditions
Li, Guangchen,Lei, Peng,Szostak, Michal
supporting information, p. 5622 - 5625 (2018/09/25)
A general, transition-metal-free, and operationally simple method for esterification of amides by a highly selective cleavage of N-C(O) bonds under exceedingly mild conditions is reported. The reaction is characterized by broad substrate scope and excellent functional group tolerance. The potential of this mild esterification is highlighted by late-stage diversification of natural products and pharmaceuticals. Conceptually, the metal-free acyl functionalization of amides represents a significant step forward as a practical alternative to ligand exchange in acylmetal intermediates.
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.
