cas 94-53-1, Piperonylic acid | Articles data

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Dobrowsky
p. 325
(1955)
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Filho et al.
p. 417,419
(1973)
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Destructible Surfactants Based on a Silicon-Oxygen Bond
A "destructible" surfactant based on the lability of a silicon-oxygen bond, trimethylammonium nitrate (1b), has been prepared and characterized along with the corresponding chloride (1a) and tetraphenylborate (1c).
Jaeger, David A.,Ward, Mary Darlene
p. 2221 - 2223
(1982)
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Gram-scale synthesis of carboxylic acids via catalytic acceptorless dehydrogenative coupling of alcohols and hydroxides at an ultralow Ru loading
Acceptorless dehydrogenative coupling (ADC) of alcohols and water/hydroxides is an emergent and graceful approach to produce carboxylic acids. Therefore, it is of high demand to develop active and practical catalysts/catalytic systems for this attractive transformation. Herein, we designed and fabricated a series of cyclometallated N-heterocyclic carbene-Ru (NHC-Ru) complexes via ligand tuning of [Ru-1], the superior complex in our previous work. Gratifyingly, gram-scale synthesis of carboxylic acids was efficiently enabled at an ultralow Ru loading (62.5 ppm) in open air. Moreover, effects of distinct ancillary NHC ligands and other parameters on this catalytic process were thoroughly studied, while further systematic studies were carried out to provide rationales for the activity trend of [Ru-1]-[Ru-7]. Finally, determination of quantitative green metrics illustrated that the present work exhibited superiority over representative literature reports. Hopefully, this study could provide valuable input for researchers who are engaging in metal-catalyzed ADC reactions.
Chen, Cheng,Cheng, Hua,Verpoort, Francis,Wang, Zhi-Qin,Wu, Zhe,Yuan, Ye,Zheng, Zhong-Hui
(2021/12/13)

Oxidation of Primary Alcohols and Aldehydes to Carboxylic Acids via Hydrogen Atom Transfer
The oxidation of primary alcohols and aldehydes to the corresponding carboxylic acids is a fundamental reaction in organic synthesis. In this paper, we report a new chemoselective process for the oxidation of primary alcohols and aldehydes. This metal-free reaction features a new oxidant, an easy to handle procedure, high isolated yields, and good to excellent functional group tolerance even in the presence of vulnerable secondary alcohols and tert-butanesulfinamides.
Tan, Wen-Yun,Lu, Yi,Zhao, Jing-Feng,Chen, Wen,Zhang, Hongbin
supporting information
p. 6648 - 6653
(2021/09/08)

Ni-NiO heterojunctions: a versatile nanocatalyst for regioselective halogenation and oxidative esterification of aromatics
Herein, we report a facile method for the synthesis of Ni-NiO heterojunction nanoparticles, which we utilized for the nuclear halogenation reaction of phenol and substituted phenols usingN-bromosuccinimide (NBS). A remarkablepara-selectivity was achieved for the halogenated products under semi-aqueous conditions. Interestingly, blocking of thepara-position of phenol offeredortho-selective halogenation. In addition, the Ni-NiO nanoparticles catalyzed the oxidative esterification of carbonyl compounds with alcohol, diol or dithiol in the presence of a catalytic amount of NBS. It was observed that the aromatic carbonyls substituted with an electron-donating group favoured nuclear halogenation, whereas an electron-withdrawing group substitution in carbonyl compounds facilitated the oxidation reaction. In addition, the catalyst was magnetically separated and recycled 10 times. The tuned electronic structure at the Ni-NiO heterojunction controlled selectivity and activity as no suchpara-selectivity was observed with commercially available NiO or Ni nanoparticles.
Bhardwaj, Nivedita,Goel, Bharat,Indra, Arindam,Jain, Shreyans K.,Singh, Ajit Kumar,Tripathi, Nancy
p. 14177 - 14183
(2021/08/16)

One-Pot Direct Oxidation of Primary Amines to Carboxylic Acids through Tandem ortho-Naphthoquinone-Catalyzed and TBHP-Promoted Oxidation Sequence
Biomimetic oxidation of primary amines to carboxylic acids has been developed where the copper-containing amine oxidase (CuAO)-like o-NQ-catalyzed aerobic oxidation was combined with the aldehyde dehydrogenase (ALDH)-like TBHP-mediated imine oxidation protocol. Notably, the current tandem oxidation strategy provides a new mechanistic insight into the imine intermediate and the seemingly simple TBHP-mediated oxidation pathways of imines. The developed metal-free amine oxidation protocol allows the use of molecular oxygen and TBHP, safe forms of oxidant that may appeal to the industrial application.
Kim, Hun Young,Oh, Kyungsoo,Si, Tengda
supporting information
p. 18150 - 18155
(2021/12/09)

Mechanistic studies into visible light-driven carboxylation of aryl halides/triflates by the combined use of palladium and photoredox catalysts
The reaction mechanism of palladium-catalyzed visible light-driven carboxylation of aryl halides and triflates with a photoredox catalyst was examined in detail. Experimental and theoretical studies indicated that the active species for photoredox- catalyzed reduction was cationic ArPd(II)+ species to generate nucleophilic ArPd(I) or its further reduced ArPd(0)- species, which reacted with CO2 to give carboxylic acids. Hydrodehalogenated compounds, main byproducts in this carboxylation, were thought to be generated by protonation of these reduced species.
Caner, Joaquim,Iwasawa, Nobuharu,Martin, Ruben,Murata, Kei,Shimomaki, Katsuya,Toriumi, Naoyuki
supporting information
p. 1846 - 1853
(2021/08/13)

Cobalt-Catalyzed Deprotection of Allyl Carboxylic Esters Induced by Hydrogen Atom Transfer
A brief, efficient method has been developed for the removal of the allyl protecting group from allyl carboxylic esters using a Co(II)/TBHP/(Me2SiH)2O catalytic system. This facile strategy displays excellent chemoselectivity, functional group tolerance, and high yields. This transformation probably occurs through the hydrogen atom transfer process, and a Co(III)-six-membered cyclic intermediate is recommended.
Li, Nan,Gui, Yizhen,Chu, Mengqi,You, Mengdi,Qiu, Xiaohan,Liu, Hejia,Wang, Shiang,Deng, Meng,Ji, Baoming
supporting information
p. 8460 - 8464
(2021/11/13)

An efficient chromium(iii)-catalyzed aerobic oxidation of methylarenes in water for the green preparation of corresponding acids
A highly efficient method to oxidize methylarenes to their corresponding acids with a reusable Cr catalyst was developed. The reaction can be carried out in water with 1 atm oxygen and K2S2O8as cooxidants, proceeds under green and mild conditions, and is suitable for the oxidation of both electron-deficient and electron-rich methylarenes, including heteroaryl methylarenes, even at the gram level. The excellent result, together with its simplicity of operation and the ability to continuously reuse the catalyst, makes this new methodology environmentally benign and cost-effective. The generality of this methodology gives it the potential for use on an industrial scale. Differing from the accepted oxidation mechanism of toluene, GC-MS studies and DFT calculations have revealed that the key benzyl alcohol intermediate is formed under the synergetic effect of the chromium and molybdenum in the Cr catalyst, which can be further oxidized to afford benzaldehyde and finally benzoic acid.
Jiang, Feng,Liu, Shanshan,Wei, Yongge,Yan, Likai,Yu, Han,Zhao, Wenshu
supporting information
p. 12413 - 12418
(2021/09/28)

1,2-Dibutoxyethane-Promoted Oxidative Cleavage of Olefins into Carboxylic Acids Using O2 under Clean Conditions
Herein, we report the first example of an effective and green approach for the oxidative cleavage of olefins to carboxylic acids using a 1,2-dibutoxyethane/O2 system under clean conditions. This novel oxidation system also has excellent functional-group tolerance and is applicable for large-scale synthesis. The target products were prepared in good to excellent yields by a one-pot sequential transformation without an external initiator, catalyst, and additive.
Ou, Jinhua,Tan, Hong,He, Saiyu,Wang, Wei,Hu, Bonian,Yu, Gang,Liu, Kaijian
p. 14974 - 14982
(2021/10/25)

Uncommon overoxidative catalytic activity in a new halo-tolerant alcohol dehydrogenase
Alcohol dehydrogenases (ADH) are versatile and useful enzymes employed as biocatalysts, especially for the selective oxidation of primary and secondary alcohols, and for the reduction of carbonyl moieties. A new alcohol dehydrogenase (HeADH-II) has been identified from the genome of the halo-adapted bacterium Halomonas elongata, which proved stable in the presence of polar organic solvents and salt exposure. Unusual for this class of enzymes, HeADH-II lacks enantiopreference and is capable of oxidizing both alcohols and aldehydes, enabling a direct overoxidation of primary alcohols to carboxylic acids. HeADH-II was coupled with a NADH-oxidase from Lactobacillus pentosus (LpNOX) to increase the process yields and allowing recycling of the cofactor. The enzymatic oxidation of primary alcohols was also paired with in situ condensation of the intermediate aldehydes with hydroxylamine to prepare the corresponding aldoximes, with particular attention to perillartine (a powerful sweetener), whose enzymatic synthesis starting from natural sources, leads to an equally natural product.
Contente, Martina L.,Fiore, Noemi,Cannazza, Pietro,Roura Padrosa, David,Molinari, Francesco,Gourlay, Louise,Paradisi, Francesca
supporting information
p. 5679 - 5685
(2020/09/17)

Method for preparing aromatic carboxylic acid compound
The invention discloses a method for preparing an aromatic carboxylic acid compound. The method comprises the following steps: 1) heating carbon dioxide and hydrosilane in the presence of a copper catalyst in a reaction medium A; and 2) adding a reaction medium B, aryl halide, a palladium catalyst and a base to the reaction mixture in the step 1), sealing the reaction system, and performing a heating reaction. The method has the advantages that raw materials are simple and easy to obtain, the raw materials are cheap and stable, the catalyst is common, easy to obtain and stable, the reaction conditionsaremild, the aftertreatment is simple, the yield is high, and the like.
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Paragraph 0085-0086; 0121-0123; 0176

(2020/02/14)

Cobalt-catalyzed carboxylation of aryl and vinyl chlorides with CO2
The transition-metal-catalyzed carboxylation of aryl and vinyl chlorides with CO2 is rarely studied, and has been achieved only with a Ni catalyst or combination of palladium and photoredox. In this work, the cobalt-catalyzed carboxylation of aryl and vinyl chlorides and bromides with CO2 has been developed. These transformations proceed under mild conditions and exhibit a broad substrate scope, affording the corresponding carboxylic acids in good to high yields.
Wang, Yanwei,Jiang, Xiaomei,Wang, Baiquan
supporting information
p. 14416 - 14419
(2020/12/01)

Cobalt-Catalyzed Reductive Carboxylation of Aryl Bromides with Carbon Dioxide
Cobalt-catalyzed reductive carboxylation of aryl bromides with carbon dioxide has been developed. The reaction proceeded under one atm pressure of CO2 at 40 °C in the presence of cobalt iodide/2,2′-bipyridine catalysts and zinc dust as a reducing reagent. Various aryl bromides could be converted to the corresponding carboxylic acids in good to high yields. Preliminary mechanistic experiments ruled out intervention of intermediate organozinc species for carboxylation with CO2, thus suggesting a direct CO2 insertion into the corresponding ArCoBr species. (Figure presented.).
Hang, Wei,Yi, Yaping,Xi, Chanjuan
supporting information
p. 2337 - 2341
(2020/04/30)

Synthesis and Biological Activity of Some New N-bridged Heterocycles of Piperonal-based Triazolo-thiadiazoles
A new series of 6-(6-nitro/bromo/hydrobenzo[d][1,3]dioxol-5-yl)-3-alkyl/aryl-[1,2,4] triazolo[3,4-b][1,3,4]thiadiazoles (4a-o) was synthesized by cyclocondensation of 6-nitro/bromobenzo/ hydro[d][1,3]dioxole-5-carboxylic acids (2a-c) with 3-alkyl/aryl-4-amino-5-mercapto-1,2,4-triazoles (3a-e) in the presence of phosphorus oxychloride as a cyclizing agent. The newly synthesized compounds were characterized by LC–MS, FT-IR, 1H-NMR, and also CHN analysis. All the newly synthesized compounds were tested for their bacterial inhibition ability along with antioxidant properties. Among the synthesized compounds, compounds 4o (11.0 ± 1.4) and 4l (10.5 ± 0.20) exhibited good bacterial inhibition against E. coli, whereas compounds 4i and 4g also showed (10.5 ± 1.8) and (10.0 ± 0.70) good inhibition against B. subtilis and S. aureus, respectively. The majority of the synthesized compounds exhibited poor antioxidant activity due to lack of electron/proton donor capacity in the synthesized compounds.
Rahiman, M. Abdul,Manju,Laksmegowda, Sharath C.,Ganagadharappa, Vasanth A.
p. 615 - 619
(2021/01/25)

Synthesis and antimicrobial evaluation of piperic acid amides and their lower homologues
Seven piperic acid amides along with their lower homologs (12) were synthesized using HATU-DIPEA coupling reagent. All the synthesized derivatives were evaluated for their antibacterial activities against Staphylococcus aureus, Pseudomonas aeruginosa, and vancomycin-resistant P. aeruginosa. They were found to be more active on P. aeruginosa than on S. aureus. However, they did not exhibit potent activity on Vancomycin resistant P. aeruginosa. Among the tested compounds, methylenedioxycinnamic acid amide of anthranilic acid (MDCA-AA, 2a) was found to be most active against S. aureus with MIC of 3.125 μg/ml. The PAS and INH amides of piperic acid were screened against Mycobacterium tuberculosis H37Ra strain. They were found to be most active among all the tested compounds but were found to be less active than the standard drug, isoniazid.
Achanta, Prabhakar S.,Raj, Sneha,Horam, Soyar,Arockiaraj, Jesu,Bobbala, Ravi Kumar,Akkinepally, Raghuram Rao,Pasupuleti, Mukesh,Achanta, Appa Rao V. N.
p. 366 - 373
(2019/12/12)

Potent arylamide derivatives as dual-target antifungal agents: Design, synthesis, biological evaluation, and molecular docking studies
Fungal infections have become a serious medical problem due to the high infection rate and the frequent emergence of drug resistance. Ergosterol is an important structural component of the fungal cell membrane, its synthetases (squalene epoxidase (SE) and 14α-demethylase (CYP51)) are considered as the key points to block the ergosterol synthesis. In this study, we designed a series of dual-target arylamides derivatives based on the analysis of active sites (SE, CYP51). Subsequently, these target compounds were synthesized, and their antifungal activity was evaluated. Most of compounds demonstrate the potent antifungal activity against multiple Candida spp. and A. fum. In particular, the antifungal activities of compounds 10b and 11c are not only superior to positive control drugs, but also have significant inhibitory effects on drug-resistant fungi (C.alb. Strain100, C.alb. Strain103). Therefore, their action mechanism was further studied. Cellular uptake and electron microscopy observation showed that target compounds were able to enter fungal cytoplasmic region through free diffusion, and destroyed cell membrane structure. At the same time, preliminary mechanisms have demonstrated that they can affect the synthesis of ergosterol by inhibiting the activity of dual targets. It is worth noting that they also can exhibit excellent antifungal activity and low toxic side effects in vivo. Their ADMET properties and binding models were established will be useful for further lead optimization.
An, Yunfei,Dong, Yue,Han, Jun,Liu, Min,Liu, Xinyong,Sun, Bin
(2020/03/27)

Diazaphosphinyl radical-catalyzed deoxygenation of α-carboxy ketones: A new protocol for chemo-selective C-O bond scission: Via mechanism regulation
C-O bond cleavage is often a key process in defunctionalization of organic compounds as well as in degradation of natural polymers. However, it seldom occurs regioselectively for different types of C-O bonds under metal-free mild conditions. Here we report a facile chemo-selective cleavage of the α-C-O bonds in α-carboxy ketones by commercially available pinacolborane under the catalysis of diazaphosphinane based on a mechanism switch strategy. This new reaction features high efficiency, low cost and good group-tolerance, and is also amenable to catalytic deprotection of desyl-protected carboxylic acids and amino acids. Mechanistic studies indicated an electron-transfer-initiated radical process, underlining two crucial steps: (1) the initiator azodiisobutyronitrile switches originally hydridic reduction to kinetically more accessible electron reduction; and (2) the catalytic phosphorus species upconverts weakly reducing pinacolborane into strongly reducing diazaphosphinane. This journal is
Cheng, Jin-Pei,Yang, Jin-Dong,Zhang, Jingjing
p. 8476 - 8481
(2020/09/07)

RhI-Catalyzed PIII-Directed C?H Bond Alkylation: Design of Multifunctional Phosphines for Carboxylation of Aryl Bromides with Carbon Dioxide
We report the C?H alkylation of biarylphosphines at the ortho′ position(s) with alkenes by using rhodium(I) catalysis, which provides straightforward access to a large library of multifunctionalized phosphines. Some of these modified ligands outperformed commercially available phosphines in the Pd-catalyzed carboxylation of aryl bromides with carbon dioxide in the presence of a photoredox catalyst.
Zhang, Zhuan,Roisnel, Thierry,Dixneuf, Pierre H.,Soulé, Jean-Fran?ois
supporting information
p. 14110 - 14114
(2019/08/30)

Method for copper-catalyzed carboxylation reaction of arylboronic acid and carbon dioxide
The invention discloses a method for a copper-catalyzed carboxylation reaction of arylboronic acid and carbon dioxide. According to the method, carbon dioxide is used as a C1 source, copper catalysisis adopted, alkoxide serves as alkali, and a reaction is carried out in an organic solvent; the method is simple in process and easy to implement, and shows wide functional group compatibility; the method allows various arylboronic acids such as monosubstituted or polysubstituted phenylboronic acid, polycyclic aromatic hydrocarbon boronic acid and benzoheterocyclic boronic acid to be converted into corresponding arylcarboxylic acids with considerable yield under mild conditions; and the produced carboxylic acids have important application value, and can be used for deriving a great number of other common chemical substances, such as acyl halide, acid anhydride, ester and amide.
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Paragraph 0097; 0098

(2019/12/29)

Palladium-Catalyzed Visible-Light-Driven Carboxylation of Aryl and Alkenyl Triflates by Using Photoredox Catalysts
A visible-light-driven carboxylation of aryl and alkenyl triflates with CO2 is developed by using a combination of Pd and photoredox catalysts. This reaction proceeds under mild conditions and can be applied to a wide range of substrates including acyclic alkenyl triflates.
Shimomaki, Katsuya,Nakajima, Tomoya,Caner, Joaquim,Toriumi, Naoyuki,Iwasawa, Nobuharu
supporting information
p. 4486 - 4489
(2019/06/24)

Carboxylation of Aryl Triflates with CO2 Merging Palladium and Visible-Light-Photoredox Catalysts
We report herein a visible-light-promoted, highly practical carboxylation of readily accessible aryl triflates at ambient temperature and a balloon pressure of CO2 by the combined use of palladium and photoredox Ir(III) catalysts. Strikingly, the stoichiometric metallic reductant is replaced by a nonmetallic amine reductant providing an environmentally benign carboxylation process. In addition, one-pot synthesis of a carboxylic acid directly from phenol and modification of estrone and concise synthesis of pharmaceutical drugs adapalene and bexarotene have been accomplished via late-stage carboxylation reaction. Furthermore, a parallel decarboxylation-carboxylation reaction has been demonstrated in an H-type closed vessel that is an interesting concept for the strategic sector. Spectroscopic and spectroelectrochemical studies indicated electron transfer from the Ir(III)/DIPEA combination to generate aryl carboxylate and Pd(0) for catalytic turnover.
Bhunia, Samir Kumar,Das, Pritha,Nandi, Shantanu,Jana, Ranjan
supporting information
p. 4632 - 4637
(2019/06/27)

Facile oxidation of alcohols to carboxylic acids in basic water medium by employing ruthenium picolinate cluster as an efficient catalyst
Selective transformation of alcohols into carboxylic acids is a crucial process in industry for the synthesis of bulk chemicals. Current methods for the production of acids involve oxygen under pressure or toxic reagents like ruthenium chlorite or iodate or chromium oxides. Herein, we report the preparation of [Ru3(CO)8(C5H4NCO2)2] cluster which is an efficient catalyst precursor for the conversion of primary alcohols into carboxylic acids under aerobic conditions. The catalytic process involves the use of NaOH in a water–isopropanol medium which gives a 90% yield of carboxylic acid (90% yield for benzoic acid in standard reaction). This clean process appears to be safe for the synthesis of various benzoic acids for both laboratory and also industrial purposes.
Singh, Ajeet,Singh, Sandip K.,Saini, Anoop K.,Mobin, Shaikh M.,Mathur, Pradeep
(2018/10/15)

Tandem one-pot CO2 reduction by PMHS and silyloxycarbonylation of aryl/vinyl halides to access carboxylic acids
The present study discloses the synthesis of aryl/vinyl carboxylic acids from Csp2-bound halides (Cl, Br, I) in a carbonylative path by using silyl formate (from CO2 and hydrosilane) as an instant CO-surrogate. Hydrosilane provides hydride for reduction and its oxidation product silanol serves as a coupling partner. Mono-, di-, and tri-carboxylic acids were obtained from the corresponding aryl/vinyl halides.
Paridala, Kumaraswamy,Lu, Sheng-Mei,Wang, Meng-Meng,Li, Can
supporting information
p. 11574 - 11577
(2018/10/31)

An Efficient Aerobic Oxidation Protocol of Aldehydes to Carboxylic Acids in Water Catalyzed by an Inorganic-Ligand-Supported Copper Catalyst
A method for the aerobic oxidation of aldehydes to carboxylic acids in water by using an inorganic-ligand-supported copper catalyst was developed. This method was performed with the use of atmospheric oxygen as the sole oxidant under extremely mild aqueous conditions, and furthermore, a wide range of aldehydes with various functional groups were tolerated. The copper catalyst could be recycled and used in successive reactions at least six times without any appreciable degradation in performance. This method is operationally simple and avoids the use of high-costing, toxic, air/moisture-sensitive, and commercially unavailable organic ligands. The generality of this method gives it potential to be used on the industrial scale.
Yu, Han,Ru, Shi,Zhai, Yongyan,Dai, Guoyong,Han, Sheng,Wei, Yongge
p. 1253 - 1257
(2018/02/16)

A heterocyclic compound and use thereof
The invention discloses a compound of a general formula I and application of the compound serving as a plant disease-resistance activator. In the formula, a substituent group R1 and 0-3 substituent groups R2 exist on the 4th, 5th, 6th and 7th sites; R1 is independently selected from -R3OOH, -R4OOR5, -R6OH and -R7-O-R8; R2 is independently selected from C1-C6 alkyl, C1-6 halogenated alkyl, C1-C6 alkoxy, C1-C6 halogenated alkoxy, hydroxyl, halogen, nitro, amino and C1-C6 alkylamino; R3, R4, R5, R6, R7 and R8 are independently selected from C1-C6 alkyl and C1-6 halogenated alkyl. The compound induces plants to generate disease resistance so as to inhibit pathogens instead of directly killing or inhibiting the pathogens. The compound has the advantages of systematicness, durability, broad spectrum, high safety and the like, so the amount of highly toxic pesticides can be reduced, and the compound is environmentally friendly and has huge industrialized and commercial prospects and market values.
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Paragraph 0103-0106; 0108-0110

(2018/05/24)

Visible-Light-Mediated Hydroxycarbonylation of Diazonium Salts
A visible light-promoted catalytic photoredox hydroxycarbonylation was achieved on aryl diazonium salts whether preformed or generated in situ from the corresponding anilines. This strategy allows a straightforward access to a variety of carboxylic acids under mild conditions. (Figure presented.).
Gosset, Cyrille,Pellegrini, Sylvain,Jooris, Romain,Bousquet, Till,Pelinski, Lydie
p. 3401 - 3405
(2018/08/06)

Studies on Iron-Catalyzed Aerobic Oxidation of Benzylic Alcohols to Carboxylic Acids
A comprehensive study on aerobic oxidation of benzylic alcohols to carboxylic acids with a catalytic amount each of Fe(NO 3) 3 ·9H 2 O, TEMPO, and KCl is conducted. Various synthetically useful functional groups are well tolerated in the reaction. Distinct electronic and steric effects are observed in the reaction: electron-withdrawing groups accelerate the reaction while electron-donating groups make the reaction slower, and ortho -substituted substrates react slower than meta -substituted substrates. Several large-scale reactions (100 mmol) are conducted using a slow air flow of 30 mL/min to demonstrate the practicality of this method in an academic laboratory.
Jiang, Xingguo,Ma, Shengming
p. 1629 - 1639
(2018/02/26)

Aerobic Oxidation of Diverse Primary Alcohols to Carboxylic Acids with a Heterogeneous Pd-Bi-Te/C (PBT/C) Catalyst
Heterogeneous catalytic aerobic oxidation methods represent a near-ideal approach for the conversion of primary alcohols to carboxylic acids. Here, we report that a heterogeneous catalyst composed of Pd, Bi, and Te supported on activated carbon is highly effective for the oxidation of diverse benzylic and aliphatic primary alcohols, including 5-(hydroxymethyl)furfural (HMF) and substrates bearing heterocycles and other important functional groups. In many cases, the desired carboxylic acid product is obtained in >90% yield. Additionally, the catalyst has been demonstrated in a continuous-flow packed-bed reactor for the oxidation of benzyl alcohol, achieving near-quantitative yield while undergoing over 30 000 turnovers.
Ahmed, Maaz S.,Mannel, David S.,Root, Thatcher W.,Stahl, Shannon S.
supporting information
p. 1388 - 1393
(2017/09/22)

Visible-Light-Driven Carboxylation of Aryl Halides by the Combined Use of Palladium and Photoredox Catalysts
A highly useful, visible-light-driven carboxylation of aryl bromides and chlorides with CO2 was realized using a combination of Pd(OAc)2 as a carboxylation catalyst and Ir(ppy)2(dtbpy)(PF6) as a photoredox catalyst. This carboxylation reaction proceeded in high yields under 1 atm of CO2 with a variety of functionalized aryl bromides and chlorides without the necessity of using stoichiometric metallic reductants.
Shimomaki, Katsuya,Murata, Kei,Martin, Ruben,Iwasawa, Nobuharu
supporting information
p. 9467 - 9470
(2017/07/24)

Synthesis of some monosaccharide-related ester derivatives as insecticidal and acaricidal agents
To develop natural-product-based pesticidal agents, a series of monosaccharide-related ester derivatives (17a–q and 18a–f), glucose (xylose)-piperic acid/piperic acid-like conjugates, were synthesized. Three-dimensional structures of compounds 17b, 17g, 17h, and 17n were unambiguously determined by single-crystal X-ray diffraction. Especially compounds 18e and 18f exhibited the most potent insecticidal and acaricidal activities against Mythimna separata and Tetranychus cinnabarinus. Their structure-activity relationships were also discussed.
Huang, Xiaobo,Zhang, Bingchuan,Xu, Hui
supporting information
p. 4336 - 4340
(2017/09/12)

Harnessing the Reactivity of Iridium Hydrides by Air: Iridium-Catalyzed Oxidation of Aldehydes to Acids in Water
An iridium-catalyzed oxidation of aldehydes to acids was realized by using air as the oxidant and water as the solvent in the presence of base. Interestingly, the same type of catalysts were also used for the reduction of aldehydes under acidic conditions. A common iridium hydride intermediate is proposed for both redox reactions. The oxidation has a number of advantages such as high yields, great functionality tolerance, and easy purification without chromatography.
Yang, Zhanhui,Luo, Renshi,Zhu, Zhongpeng,Yang, Xuerong,Tang, Weiping
supporting information
p. 4095 - 4098
(2017/11/21)

4-Alkyliden-azetidinones modified with plant derived polyphenols: Antibacterial and antioxidant properties
Antimicrobial resistance is one of the major and growing concerns in hospital- and community acquired infections, and new antimicrobial agents are therefore urgently required. It was reported that oxidative stress could contribute to the selection of resistant bacterial strains, since reactive oxygen species (ROS) revealed to be an essential driving force. In the present work 4-alkylidene-azetidinones, a new class of antibacterial agents, were functionalized with phytochemical polyphenolic acids such as protocatechuic, piperonyl, caffeic, ferulic, or sinapic acids and investigated as dual target antibacterial-antioxidant compounds. The best candidates showed good activities against multidrug resistant clinical isolates of MRSA (MICs 2–8 μg/mL). Among the new compounds, two revealed the best antioxidant capacity with TEAC-DPPH and TEAC-ABTS being significantly more active than Trolox.
Giacomini, Daria,Musumeci, Rosario,Galletti, Paola,Martelli, Giulia,Assennato, Lorenzo,Sacchetti, Gianni,Guerrini, Alessandra,Calaresu, Enrico,Martinelli, Marianna,Cocuzza, Clementina
p. 604 - 614
(2017/10/10)

Palladium-catalyzed oxidative coupling of arylboronic acid with isocyanide to form aromatic carboxylic acids
A valuable palladium-catalyzed oxidative coupling of aryl- and alkenyl borides with isocyanide for the synthesis of corresponding carboxylic acids has been developed. With wide substrate scopes and good functional group tolerance, this reaction offers corresponding carboxylic acids in moderate to excellent yields.
Chen, Zhen-Bang,Liu, Kui,Zhang, Fang-Ling,Yuan, Qing,Zhu, Yong-Ming
p. 8078 - 8083
(2017/10/10)

Accessing N-Acyl Azoles via Oxoammonium Salt-Mediated Oxidative Amidation
An operationally simple, robust, metal-free approach to the synthesis of N-acyl azoles from both alcohols and aldehydes is described. Oxidative amidation is facilitated by a commercially available organic oxidant (4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxoammonium tetrafluoroborate) and proceeds under very mild conditions for an array of structurally diverse substrates. Tandem reactions of these activated amides, such as transamidation and esterification, enable further elaboration. Also, the spent oxidant can be recovered and used to regenerate the oxoammonium salt.
Ovian, John M.,Kelly, Christopher B.,Pistritto, Vincent A.,Leadbeater, Nicholas E.
supporting information
p. 1286 - 1289
(2017/03/22)

Room Temperature Carbonylation of (Hetero) Aryl Pentafluorobenzenesulfonates and Triflates using Palladium-Cobalt Bimetallic Catalyst: Dual Role of Cobalt Carbonyl
An efficient method for the carbonylation of (hetero) aryl pentafluorobenzenesulfonates and triflates under exceptionally mild conditions using palladium/dicobalt octacarbonyl [Pd/Co2(CO)8] has been developed. Besides acting as carbon monoxide (CO) source, Co2(CO)8enhances the reaction rate by accelerating the CO insertion through an in situ generated bimetallic palladium cobalt tetracarbonyl [Pd-Co(CO)4] complex. Under the optimized reaction condition, carbonylation of a wide range of activated and deactivated, as well as sterically hindered and heteroaromatic, substrates proceeded efficiently at room temperature. The high chemoselectivity and improved synthesis of biologically relevant Isoguvacine and Lazabemide intermediates highlights its scope as a valuable synthetic method. The generality of this protocol was further extended to other electrophiles (bromides, chlorides and tosylates). (Figure presented.).
Joseph, Jayan T.,Sajith, Ayyiliath M.,Ningegowda, Revanna C.,Shashikanth, Sheena
p. 419 - 425
(2017/02/10)

Nitrous Oxide as a Hydrogen Acceptor for the Dehydrogenative Coupling of Alcohols
The oxidation of alcohols with N2O as the hydrogen acceptor was achieved with low catalyst loadings of a rhodium complex that features a cooperative bis(olefin)amido ligand under mild conditions. Two different methods enable the formation of either the corresponding carboxylic acid or the ester. N2 and water are the only by-products. Mechanistic studies supported by DFT calculations suggest that the oxygen atom of N2O is transferred to the metal center by insertion into the Rh-H bond of a rhodium amino hydride species, generating a rhodium hydroxy complex as a key intermediate.
Gianetti, Thomas L.,Annen, Samuel P.,Santiso-Quinones, Gustavo,Reiher, Markus,Driess, Matthias,Grützmacher, Hansj?rg
supporting information
p. 1854 - 1858
(2016/02/03)

Acceptorless dehydrogenation and aerobic oxidation of alcohols with a reusable binuclear rhodium(II) catalyst in water
A water-soluble binuclear rhodium(ii) complex was found to be an efficient catalyst for both acceptorless dehydrogenation and aerobic oxidation of alcohols under air to produce carboxylic acids or ketones in water. The catalyst is highly efficient with substrate/catalyst ratios up to 5 × 103 being feasible, and could be recycled 19 times without significant loss of activity.
Wang, Xuewei,Wang, Chao,Liu, Yuxuan,Xiao, Jianliang
supporting information
p. 4605 - 4610
(2016/09/04)

Platinum nanoparticles supported on polymeric ionic liquid functionalized magnetic silica: effective and reusable heterogeneous catalysts for the selective oxidation of alcohols in water
In this research, the syntheses of core-shell magnetic silica nanostructures, functionalized by a polymeric ionic liquid and immobilization of platinum nanoparticles, are described. Firstly, the magnetic silica nanoparticles were synthesized and modified using an amine-containing organosilane through a single-step process. The synthesized nanostructures were functionalized by the synthesis and polymerization of a pyridinium ionic liquid and a methyl methacrylate monomer, respectively, onto their surfaces. The platinum nanoparticles were immobilized on the functionalized nanoparticles. The obtained functionalized nanostructures have been used in the selective aerobic oxidation, in an aqueous medium, of primary and encumbered secondary aliphatic alcohols, and exhibit high activity at mild temperatures.
Vessally, Esmail,Ghasemisarabbadeih, Mostafa,Ekhteyari, Zeynab,Hosseinzadeh-Khanmiri, Rahim,Ghorbani-Kalhor, Ebrahim,Ejlali, Ladan
p. 106769 - 106777
(2016/11/25)

Catalytic Fehling's Reaction: An Efficient Aerobic Oxidation of Aldehyde Catalyzed by Copper in Water
The first example of homogeneous copper-catalyzed aerobic oxidation of aldehydes is reported. This method utilizes atmospheric oxygen as the sole oxidant, proceeds under extremely mild aqueous conditions, and covers a wide range of various functionalized aldehydes. Chromatography is generally not necessary for product purification.
Liu, Mingxin,Li, Chao-Jun
supporting information
p. 10806 - 10810
(2016/09/03)

Aerobic flow oxidation of alcohols in water catalyzed by platinum nanoparticles dispersed in an amphiphilic polymer
We have developed a technique for the aqueous aerobic flow oxidation of alcohols in a continuous-flow reactor containing platinum nanoparticles dispersed on an amphiphilic polystyrene-poly(ethylene glycol) resin (ARP-Pt). Various primary and secondary alcohols including aliphatic, aromatic and heteroaromatic alcohols were efficiently oxidized within 73 seconds in a flowing aqueous system at 100-120°C under 40-70 bar of the system pressure to give the corresponding carboxylic acids and ketones, respectively, in up to 99% yield. Benzaldehydes could be also prepared selectively from benzyl alcohols by conducting the flow oxidation under the standard conditions in the presence of triethylamine. Moreover, a practical gram-scale synthesis of surfactants was realized in the aqueous aerobic continuous flow oxidation for 36-116 hours. This aerobic flow oxidation system provides a safe, clean, green, rapid and efficient practical method for oxidizing alcohols.
Osako, Takao,Torii, Kaoru,Uozumi, Yasuhiro
p. 2647 - 2654
(2015/02/05)

Copper-catalyzed synthesis of aromatic carboxylic acids from arylboronic acids and acetyl acetate
A simple and efficient copper-catalyzed method for the synthesis of aromatic carboxylic acids in moderate to high yields with great functional-group compatibility in the substrates has been developed. The new method uses readily available arylboronic acids and acetyl acetate as the starting materials and inexpensive CuI as the catalyst.
Zheng, Rui,Zhou, Qizhong,Gu, Haining,Jiang, Huajiang,Wu, Jiashou,Jin, Zhengneng,Han, Deman,Dai, Guoliang,Chen, Rener
supporting information
p. 5671 - 5675
(2014/12/11)

Oxidative cleavage of α-sulfonyl ketones to carboxylic acids with Ce(NH4)2(NO3)6
Tandem oxidative cleavage of α-sulfonyl arylketones 2 with the combination of Ce(NH4)2(NO3)6 and O2 in MeCN afforded carboxylic acids 3 in moderate to good yields. The plausible reaction mechanism has
Chang, Meng-Yang,Tsai, Chung-Yu
supporting information
p. 5548 - 5550
(2014/12/11)

Cooperative N-Heterocyclic Carbene (NHC) and Ruthenium Redox Catalysis: Oxidative Esterification of Aldehydes with Air as the Terminal Oxidant
The paper describes a cooperative NHC (N-heterocyclic carbene) and ruthenium-based redox catalysis for the mild aerobic oxidative esterification of various aromatic and heteroaromatic aldehydes. The ruthenium(II) complex Ru(bpz)3(PF6)2 (bpz=2,2′-bipyrazine) as catalyst is shown to be compatible with free NHCs. The NHC is used in these cascade reactions for the umpolung of the aldehyde to form the corresponding Breslow intermediate which in turn gets oxidized to an acylazolium ion by the ruthenium redox catalyst. Air is used as a terminal oxidant for oxidation (regeneration) of the ruthenium catalyst. In addition, we will show that in the absence of the ruthenium redox catalyst and alcohol, NHC-catalyzed aerobic oxidation of aldehydes delivers the corresponding acids in good to excellent yields. Mechanistic studies and DFT calculations supporting our suggested mechanisms are provided. Copyright
Zhao, Junfeng,Mueck-Lichtenfeld, Christian,Studer, Armido
supporting information
p. 1098 - 1106
(2013/05/21)

Correlation of the rates of solvolysis of electron-rich benzoyl chloride using the extended Grunwald-Wistein equation
The solvolysis rate constants of piperonyloyl chloride (1) in 27 different solvents are well correlated with the extended Grunwald-Winstein equation, using the NT solvent nucleophilicity scale, YCl solvent ionizing scale, and I aromatic ring parameter with sensitivity values of 0.30 ± 0.05, 0.71 ± 0.02, and 0.60 ± 0.04 for l, m, and h, respectively. The solvent kinetic isotope effect values (SKIE, kMeOH/kMeOD and k 50%MeOD-50%D2O) of 1.16 and 1.12 were also in accord with the values for the SN1 mechanism and/or the dissociative SN2 mechanism. The product selectivity values (S) for solvolysis of 1 in alcohol/water mixtures were in the range of 0.5 to 1.9, which is also consistent with the proposed unimolecular ionization mechanism.
Oh, Hyunjung,Choi, Hojune,Park, Jong Keun,Yang, Kiyull,Koo, In Sun
p. 2697 - 2701
(2013/10/22)

Production of natural fragrance aromatic acids by coexpression of trans-anethole oxygenase and p-anisaldehyde dehydrogenase genes of Pseudomonas putida JYR-1 in Escherichia coli
A gene encoding p-anisaldehyde dehydrogenase (PAADH), which catalyzes the oxidation of p-anisaldehyde to p-anisic acid, was identified to be clustered with the trans-anethole oxygenase (tao) gene in Pseudomonas putida JYR-1. Heterologously expressed PAADH in Escherichia coli catalyzed the oxidation of vanillin, veratraldehyde, and piperonal to the corresponding aromatic acids vanillic acid, veratric acid, and piperonylic acid, respectively. Coexpression of trans-anethole oxygenase (TAO) and PAADH in E. coli also resulted in the successful transformation of trans-anethole, isoeugenol, O-methyl isoeugenol, and isosafrole to p-anisic acid, vanillic acid, veratric acid, and piperonylic acid, respectively, which are compounds found in plants as secondary metabolites. Because of the relaxed substrate specificity and high transformation rates by coexpressed TAO and PAADH in E. coli, the engineered strain has potential to be applied in the fragrance industry.
Han, Dongfei,Kurusarttra, Somwang,Ryu, Ji-Young,Kanaly, Robert A.,Hur, Hor-Gil
p. 11972 - 11979
(2013/02/23)

Silver(i)-catalyzed carboxylation of arylboronic esters with CO2
A variety of arylboronic esters were efficiently carboxylated with CO 2 using a simple AgOAc/PPh3 catalyst, affording the corresponding carboxylic acids in good yield. This simple and efficient silver(i) catalytic system showed wide functional group compatibility. The Royal Society of Chemistry 2012.
Zhang, Xiao,Zhang, Wen-Zhen,Shi, Ling-Long,Guo, Chun-Xiao,Zhang, Ling-Ling,Lu, Xiao-Bing
supporting information; experimental part
p. 6292 - 6294
(2012/07/16)

Process for the carboxylation of aryl halides with palladium catalysts
A process for the carboxylation of an aryl halide to yield an aryl carboxylic acid, in which the aryl halide and CO2 are contacted in an organic solvent under inert atmosphere and in the presence of a reducing agent and an adequate catalyst system.
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(2011/05/04)

PEG1000-DAIL/toluene temperature-dependent biphasic system that regulate homogeneously catalyzed oxidation of primary alcohols to carboxylic acids
An efficient and convenient procedure for the hydrogen peroxide oxidation of primary alcohols to the carboxylic acids in aqueous media in regulated temperature-dependant; recyclable phase-separation catalytic system comprised of the PEG1000-based dicationic acidic ionic liquid and toluene under homogeneous conditions in good to excellent yield is reported.
Hu, Yu Lin,Ma, Xiao Yun,Ge, Qiang,Lu, Ming
experimental part
p. 927 - 930
(2011/09/15)

KMnO4-mediated oxidation as a continuous flow process
An efficient and easily scalable transformation of alcohols and aldehydes to carboxylic acids and nitroalkane derivatives to the corresponding carbonyls and carboxylic acids using permanganate as the oxidant within a continuous flow reactor is reported. Notably, the generation and downstream processing of MnO2 slurries was not found to cause any blocking of the reactor when ultrasound pulses were applied to the flow system.
Sedelmeier, Joerg,Ley, Steven V.,Baxendale, Ian R.,Baumann, Marcus
supporting information; experimental part
p. 3618 - 3621
(2010/11/17)

Pd/C and NaBH4 in basic aqueous alcohol: An efficient system for an environmentally benign oxidation of alcohols
We report the oxidation of a wide range of alcohols using an environmentally benign and economical process. The use of Pd/C heterogeneous catalysts along with NaBH4in aqueous ethanol or methanol and either K2CO3 or KOH as base at room temperature under molecular oxygen or air give the corresponding oxidation products. This protocol is versatile since it is capable of oxidizing alcohols to its desired carbonyl or carboxyl counterpart. Room temperature reaction in aqueous system and recyclability of the catalyst are among the advantages of this manipulation. These advantages make the process safe and cheaper rendering it favorable from both economic and environmental viewpoints. Georg Thieme Verlag Stuttgart New York.
An, Gwangil,Ahn, Hyunseok,De Castro, Kathlia A.,Rhee, Hakjune
experimental part
p. 477 - 485
(2010/06/13)

Palladium-catalyzed direct carboxylation of aryl bromides with carbon dioxide
(Chemical Equation Presented) A novel protocol for the direct carbon dioxide insertion (CO2) into aryl halides in a catalytic manner is presented herein. Unlike other carboxylation methods using CO2, there is no need for the synthesis of the corresponding organometallic intermediates. Additionally, and in contrast to the well-established carbonylation processes, our protocol does not use highly toxic CO for the preparation of benzoic acids. Furthermore, this method is distinguished by its mild conditions, allowing the tolerance of a wide range of functional groups and substitution patterns. The crucial step of the process involves a challenging catalytic CO2 insertion into Pd-C bonds. Copyright
Correa, Arkaitz,Martin, Ruben
supporting information; experimental part
p. 15974 - 15975
(2010/02/15)