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Mechanochemical Grignard Reactions with Gaseous CO2 and Sodium Methyl Carbonate**
A one-pot, three-step protocol for the preparation of Grignard reagents from organobromides in a ball mill and their subsequent reactions with gaseous carbon dioxide (CO2) or sodium methyl carbonate providing aryl and alkyl carboxylic acids in up to 82 % yield is reported. Noteworthy are the short reaction times and the significantly reduced solvent amounts [2.0 equiv. for liquid assisted grinding (LAG) conditions]. Unexpectedly, aryl bromides with methoxy substituents lead to symmetric ketones as major products.
Pfennig, Victoria S.,Villella, Romina C.,Nikodemus, Julia,Bolm, Carsten
supporting information

(2022/01/22)

Efficiency of lithium cations in hydrolysis reactions of esters in aqueous tetrahydrofuran
Lithium cations were observed to accelerate the hydrolysis of esters with hydroxides (KOH, NaOH, LiOH) in a water/tetrahydrofuran (THF) two-phase system. Yields in the hydrolysis of substituted benzoates and aliphatic esters using the various hydroxides were compared, and the effects of the addition of lithium salt were examined. Moreover, it was presumed that a certain amount of LiOH was dissolved in THF by the coordination of THF with lithium cation and hydrolyzed esters even in the THF layer, as in the reaction by a phase-transfer catalyst.
Harada, Yumi,Hayashi, Kazuhiko,Ichimaru, Yoshimi,Imai, Masanori,Kojima, Yuki,Maeda, Azusa,Nakayama, Kanae,Sugiura, Kirara
p. 581 - 594
(2021/06/06)

Milled Dry Ice as a C1 Source for the Carboxylation of Aryl Halides
The use of carbon dioxide as a C1 chemical feedstock remains an active field of research. Here we showcase the use of milled dry ice as a method to promote the availability of CO 2in a reaction solution, permitting practical synthesis of arylcarboxylic acids. Notably, the use of milled dry ice produces marked increases in yields relative to those obtained with gaseous CO 2, as previously reported in the literature.
O'Brien, Connor J.,Nicewicz, David A.
supporting information
p. 814 - 816
(2021/03/01)

Demonstrating Ligandability of the LC3A and LC3B Adapter Interface
Autophagy is the common name for a number of lysosome-based degradation pathways of cytosolic cargos. The key components of autophagy are members of Atg8 family proteins involved in almost all steps of the process, from autophagosome formation to their selective fusion with lysosomes. In this study, we show that the homologous members of the human Atg8 family proteins, LC3A and LC3B, are druggable by a small molecule inhibitor novobiocin. Structure-activity relationship (SAR) studies of the 4-hydroxy coumarin core scaffold were performed, supported by a crystal structure of the LC3A dihydronovobiocin complex. The study reports the first nonpeptide inhibitors for these protein interaction targets and will lay the foundation for the development of more potent chemical probes for the Atg8 protein family which may also find applications for the development of autophagy-mediated degraders (AUTACs).
Hartmann, Markus,Huber, Jessica,Kramer, Jan S.,Heering, Jan,Pietsch, Larissa,Stark, Holger,Odadzic, Dalibor,Bischoff, Iris,Fürst, Robert,Schr?der, Martin,Akutsu, Masato,Chaikuad, Apirat,D?tsch, Volker,Knapp, Stefan,Biondi, Ricardo M.,Rogov, Vladimir V.,Proschak, Ewgenij
p. 3720 - 3746
(2021/05/04)

Design, synthesis, and biological studies of novel 3-benzamidobenzoic acid derivatives as farnesoid X receptor partial agonist
Farnesoid X receptor (FXR), a bile acid-activated nuclear receptor, regulates the metabolism of bile acid and lipids as well as maintains the stability of internal environment. FXR was considered as a therapeutic target of liver disorders, such as drug-induced liver injury, fatty liver and cholestasis. The previous reported FXR partial agonist 6 was a suitable lead compound in terms of its high potent and low molecular size, while the docking study of compound 6 suggested a large unoccupied hydrophobic pocket, which might be provided more possibility of structure-activity relationship (SAR) study. In this study, we have performed comprehensive SAR and molecular modeling studies based on lead compound 6. All of these efforts resulted in the identification of a novel series of FXR partial agonists. In this series, compound 41 revealed the best activity and strong interaction with binding pocket of FXR. Moreover, compound 41 protected mice against acetaminophen-induced hepatotoxicity by the regulation of FXR-related gene expression and improving antioxidant capacity. In summary, these results suggest that compound 41 is a promising FXR partial agonist suitable for further investigation.
Hu, Lijun,Ren, Qiang,Deng, Liming,Zhou, Zongtao,Cai, Zongyu,Wang, Bin,Li, Zheng
supporting information

(2020/12/25)

Combining photoredox catalysis and oxoammonium cations for the oxidation of aromatic alcohols to carboxylic acids
A methodology is reported for converting alcohols to the corresponding carboxylic acids. A dual catalytic system involving a merger of photoredox catalysis and 4-acetamido-TEMPO is employed to carry out this oxidation process.
Nandi, Jyoti,Hutcheson, Ellen L.,Leadbeater, Nicholas E.
supporting information

(2020/12/25)

Aerobic oxidation of aldehydes to carboxylic acids catalyzed by recyclable ag/c3 n4 catalyst
The oxidation of aldehydes is an efficient methodology for the synthesis of carboxylic acids. Herein we hope to report a simple, efficient and recyclable protocol for aerobic oxidation of aldehydes to carboxylic acid by using C3N4 supported silver nanoparticles (Ag/C3N4) as a catalyst in aqueous solution under mild conditions. Under standard conditions, the corresponding carboxylic acids can be obtained in good to excellent yields. In addition, Ag/C3N4 is convenient for recovery and could be reused three times with satisfactory yields.
Wu, Chaolong,Yao, Xiaoquan,Yu, Min,Zhou, Li,Zhu, Li
p. 167 - 175
(2021/03/19)

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)

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)

Disproportionation of aliphatic and aromatic aldehydes through Cannizzaro, Tishchenko, and Meerwein–Ponndorf–Verley reactions
Disproportionation of aldehydes through Cannizzaro, Tishchenko, and Meerwein–Ponndorf–Verley reactions often requires the application of high temperatures, equimolar or excess quantities of strong bases, and is mostly limited to the aldehydes with no CH2 or CH3 adjacent to the carbonyl group. Herein, we developed an efficient, mild, and multifunctional catalytic system consisting AlCl3/Et3N in CH2Cl2, that can selectively convert a wide range of not only aliphatic, but also aromatic aldehydes to the corresponding alcohols, acids, and dimerized esters at room temperature, and in high yields, without formation of the side products that are generally observed. We have also shown that higher AlCl3 content favors the reaction towards Cannizzaro reaction, yet lower content favors Tishchenko reaction. Moreover, the presence of hydride donor alcohols in the reaction mixture completely directs the reaction towards the Meerwein–Ponndorf–Verley reaction. Graphic abstract: [Figure not available: see fulltext.].
Sharifi, Sina,Sharifi, Hannah,Koza, Darrell,Aminkhani, Ali
p. 803 - 808
(2021/07/20)

Ceramic boron carbonitrides for unlocking organic halides with visible light
Photochemistry provides a sustainable pathway for organic transformations by inducing radical intermediates from substrates through electron transfer process. However, progress is limited by heterogeneous photocatalysts that are required to be efficient, stable, and inexpensive for long-term operation with easy recyclability and product separation. Here, we report that boron carbonitride (BCN) ceramics are such a system and can reduce organic halides, including (het)aryl and alkyl halides, with visible light irradiation. Cross-coupling of halides to afford new C-H, C-C, and C-S bonds can proceed at ambient reaction conditions. Hydrogen, (het)aryl, and sulfonyl groups were introduced into the arenes and heteroarenes at the designed positions by means of mesolytic C-X (carbon-halogen) bond cleavage in the absence of any metal-based catalysts or ligands. BCN can be used not only for half reactions, like reduction reactions with a sacrificial agent, but also redox reactions through oxidative and reductive interfacial electron transfer. The BCN photocatalyst shows tolerance to different substituents and conserved activity after five recycles. The apparent metal-free system opens new opportunities for a wide range of organic catalysts using light energy and sustainable materials, which are metal-free, inexpensive and stable. This journal is
Yuan, Tao,Zheng, Meifang,Antonietti, Markus,Wang, Xinchen
p. 6323 - 6332
(2021/05/19)

Selectively Upgrading Lignin Derivatives to Carboxylates through Electrochemical Oxidative C(OH)?C Bond Cleavage by a Mn-Doped Cobalt Oxyhydroxide Catalyst
Oxidative cleavage of C(OH)?C bonds to afford carboxylates is of significant importance for the petrochemical industry and biomass valorization. Here we report an efficient electrochemical strategy for the selective upgrading of lignin derivatives to carboxylates by a manganese-doped cobalt oxyhydroxide (MnCoOOH) catalyst. A wide range of lignin-derived substrates with C(OH)-C or C(O)-C units undergo efficient cleavage to corresponding carboxylates in excellent yields (80–99 %) and operational stability (200 h). Detailed investigations reveal a tandem oxidation mechanism that base from the electrolyte converts secondary alcohols and their derived ketones to reactive nucleophiles, which are oxidized by electrophilic oxygen species on MnCoOOH from water. As proof of concept, this approach was applied to upgrade lignin derivatives with C(OH)-C or C(O)-C motifs, achieving convergent transformation of lignin-derived mixtures to benzoate and KA oil to adipate with 91.5 % and 64.2 % yields, respectively.
Zhou, Hua,Li, Zhenhua,Xu, Si-Min,Lu, Lilin,Xu, Ming,Ji, Kaiyue,Ge, Ruixiang,Yan, Yifan,Ma, Lina,Kong, Xianggui,Zheng, Lirong,Duan, Haohong
supporting information
p. 8976 - 8982
(2021/03/16)

Tumor diagnosis and treatment fluorescent probe for targeting tumor Wolburg effect
The invention discloses a tumor diagnosis and treatment fluorescent probe for targeting tumor Warburg effect, and the structure of the fluorescent probe is shown as a formula (I). The fluorescent probe can be directly used in a cell line to analyze and detect the expression degree of tumor cell GLUT1 protein, so as to complete the screening of tumor cells. Meanwhile, tumor cell proliferation is inhibited by directly blocking the GLUT1 channel to inhibit intake of sugar nutritional ingredients by tumors. And an effective means and a useful tool are provided for early screening and diagnosis oftumors, development of new anti-tumor drugs and the like.
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(2020/11/02)

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)

Palladium supported on a novel ordered mesoporous polypyrrole/carbon nanocomposite as a powerful heterogeneous catalyst for the aerobic oxidation of alcohols to carboxylic acids and ketones on water
Preparation of an ordered mesoporous polypyrrole/carbon (PPy/OMC) composite has been described through a two-step nanocasting process using KIT-6 as a template. Characterization of the PPy/OMC nanocomposite by various analysis methods such as TEM, XRD, TGA, SEM and N2 sorption confirmed the preparation of a material with ordered mesoporous structure, uniform pore size distribution, high surface area and high stability. This nanocomposite was then used for the immobilization of palladium nanoparticles. The nanoparticles were almost uniformly distributed on the support with a narrow particle size of 20-25 nm, confirmed by various analysis methods. Performance of the Pd?PPy/OMC catalyst was evaluated in the aerobic oxidation of various primary and secondary alcohols on water as a green solvent, giving the corresponding carboxylic acids and ketones in high yields and excellent selectivity. The catalyst could also be reused for at least 10 reaction runs without losing its catalytic activity and selectivity. High catalytic efficiency of the catalyst can be attributed to a strong synergism between the PPy/OMC and that of supported Pd nanoparticles.
Ganji, Nasim,Karimi, Babak,Najafvand-Derikvandi, Sepideh,Vali, Hojatollah
p. 13616 - 13631
(2020/04/24)

Acceptorless dehydrogenative oxidation of primary alcohols to carboxylic acids and reduction of nitroarenes via hydrogen borrowing catalyzed by a novel nanomagnetic silver catalyst
A novel silver nano magnetic catalyst was devised for dehydrogenative oxidation of aromatic and aliphatic alcohols to the corresponding acid with water as the sole oxygen source and hydrogen gas as the only by-product. The designed catalytic system advantages from easy recovery of magnetic materials i.e. magnetic decantation, being economically viable and environmentally friendly. Furthermore, the catalytic reaction is able to reduce aryl nitro compounds in the absence of any reducing agent.
Yazdani, Elahe,Heydari, Akbar
supporting information

(2020/08/14)

Preparation method of bimetallic catalyst oxidation aldehyde synthetic carboxylic acid (by machine translation)
The method is, in a reaction solvent: under normal pressure oxygen condition, under the action of a bimetallic catalyst under the action of a bimetallic catalyst under the action of a bimetallic catalyst under the action of a bimetallic catalyst, at, DEG, under stirring . under a stirring condition with an aldehyde compound as a substrate 10-90 °C in a reaction solvent under, a stirring condition under the action of a bimetallic catalyst . The reaction solution is stirred, for. 1-12h, hours at; room temperature, under, the action, of a bimetallic 1:1 catalyst Cu(OAc) under the action of a bimetallic catalyst under the action of a bimetallic catalyst under the action of a double-metal catalyst. 2 · H2 O And Co(OAc)2 · 44H2 O As the bimetallic catalyst, can achieve the highest yield of the carboxylic acid product, in high yield, by adjusting the reaction temperature, solvent, catalyst amount, for different types of the raw material aldehyde 98%. (by machine translation)
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Paragraph 0017

(2020/05/30)

Light and oxygen-enabled sodium trifluoromethanesulfinate-mediated selective oxidation of C-H bonds
Visible light-induced organic reactions are important chemical transformations in organic chemistry, and their efficiency highly depends on suitable photocatalysts. However, the commonly used photocatalysts are precious transition-metal complexes and elaborate organic dyes, which hamper large-scale production due to high cost. Here, for the first time, we report a novel strategy: light and oxygen-enabled sodium trifluoromethanesulfinate-mediated selective oxidation of C-H bonds, allowing high-value-added aromatic ketones and carboxylic acids to be easily prepared in high-to-excellent yields using readily available alkyl arenes, methyl arenes and aldehydes as materials. The mechanistic investigations showed that the treatment of inexpensive and readily available sodium trifluoromethanesulfinate with oxygen under irradiation of light could in situ form a pentacoordinate sulfide intermediate as an efficient photosensitizer. The method represents a highly efficient, economical and environmentally friendly strategy, and the light and oxygen-enabled sodium trifluoromethanesulfinate photocatalytic system represents a breakthrough in photochemistry. This journal is
Fu, Hua,Liu, Can,Liu, Yong,Yang, Haijun,Zhu, Xianjin
supporting information
p. 4357 - 4363
(2020/07/14)

Green synthesis method of aromatic acid
The invention discloses a green synthesis method of aromatic acid. Nickel-catalyzed carbonyl insertion is carried out on aryl iodine in the presence of formate, acid anhydride, a phosphine ligand andan organic solvent by using a nickel catalyst to obtain the aromatic acid. Efficient catalytic conversion is realized by utilizing the cheap nickel catalyst, the reaction conditions are mild, and theoperation is simple.
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Paragraph 0048-0122; 0135-0140; 0271-0272

(2020/05/01)

Nickel-catalyzed carboxylation of aryl iodides with lithium formate through catalytic CO recycling
A protocol for the Ni-catalyzed carboxylation of aryl iodides with formate has been developed with good functional group compatibility for the synthesis of a variety of aromatic carboxylic acids under mild conditions. The reaction tolerates other functionalities for cross-coupling, such as aryl bromide, aryl chloride, aryl tosylate, and aryl pinacol boronate. The reaction proceeds through a carbonylation process with in situ generated carbon monoxide in the presence of a catalytic amount of acetic anhydride and lithium formate, avoiding the use of gaseous CO. The strategy of CO recycling in catalytic amounts is critical for the success of the reaction.
Fu, Ming-Chen,Fu, Yao,Shang, Rui,Wu, Ya-Nan
supporting information
p. 4067 - 4069
(2020/04/20)

Copper (II) immobilized on magnetically separable L-arginine-β-cyclodextrin ligand system as a robust and green catalyst for direct oxidation of primary alcohols and benzyl halides to acids in neat conditions
Copper (II) immobilized on L-arginine-β-cyclodextrin-functionalized magnetite nanoparticles (nano-Fe3O4@L-arginine-CD-Cu(II)) were successfully synthesized and fully characterized using FT-IR, XRD, SEM, EDX, ICP, TGA and VSM techniques. The catalytic activity of these magnetically retrievable nanoparticles was evaluated in the direct oxidation of primary alcohols and benzyl halides to acids in neat conditions that was observed to proceed well and products were obtained in good yields. In addition to showing good catalytic activity, the magnetic catalyst is easy to synthesize and can be recycled at least five times with little loss in activity.
Nejad, Masoumeh Jadidi,Salamatmanesh, Arefe,Heydari, Akbar
(2020/02/11)

Cp2TiCl2-Catalyzed Carboxylation of Aryl Chlorides with Carbon Dioxide in the Presence of n-BuMgCl
Cp2TiCl2-catalyzed carboxylation of aryl chlorides with carbon dioxide to afford benzoic acids in good yields has been achieved in the presence of n-BuMgCl. The reaction proceeds by a sequential magnesium halide exchange reaction and carboxylation with CO2 in a wide variety of aryl chlorides under mild conditions.
Hang, Wei,Yi, Yaping,Xi, Chanjuan
supporting information
p. 1476 - 1479
(2020/01/21)

Platinum on carbon–catalyzed and chemoselective aqueous oxygen oxidation of aromatic acetals to benzoic acids
Novel chemoselective transformations can diversify the synthetic pathways of the target molecules. The chemoselective oxidation of aromatic acetals to benzoic acid derivatives under platinum on carbon (Pt/C)–catalyzed oxygen oxidation conditions has been newly developed with a tolerance of aliphatic acetals and ketals. The present oxidation was clean and useful from the viewpoint of the easy removal of Pt/C and the use of molecular oxygen as a green oxidant in water as an abundant, non-toxic and environmentally friendly solvent.
Yasukawa, Naoki,Matsuda, Takumi,Shimizu, Eisho,Sajiki, Hironao,Sawama, Yoshinari
p. 145 - 152
(2020/01/28)

Palladium-catalyzed carbonylative synthesis of acylstannanes from aryl iodides and hexamethyldistannane
In this communication, we describe a new method for the carbonylative synthesis of acylstannanes from aryl iodides and hexamethyldistannane. With Pd(PPh3)4 as the catalyst and toluene as the solvent at 60 °C under 10 bar CO for 16 h, the desired acylstannanes were obtained in good to excellent yields. In order to facilitate isolation and analysis, the obtained acylstannanes were transformed into the corresponding benzoic acids by simply stirring under air for 5 h.
Chen, Bo,Franke, Robert,Wu, Xiao-Feng,Xu, Jian-Xing,Yuan, Yang
(2020/07/21)

Exploration of New Biomass-Derived Solvents: Application to Carboxylation Reactions
A range of hitherto unexplored biomass-derived chemicals have been evaluated as new sustainable solvents for a large variety of CO2-based carboxylation reactions. Known biomass-derived solvents (biosolvents) are also included in the study and the results are compared with commonly used solvents for the reactions. Biosolvents can be efficiently applied in a variety of carboxylation reactions, such as Cu-catalyzed carboxylation of organoboranes and organoboronates, metal-catalyzed hydrocarboxylation, borocarboxylation, and other related reactions. For many of these reactions, the use of biosolvents provides comparable or better yields than the commonly used solvents. The best biosolvents identified are the so far unexplored candidates isosorbide dimethyl ether, acetaldehyde diethyl acetal, rose oxide, and eucalyptol, alongside the known biosolvent 2-methyltetrahydrofuran. This strategy was used for the synthesis of the commercial drugs Fenoprofen and Flurbiprofen.
Gevorgyan, Ashot,Hopmann, Kathrin H.,Bayer, Annette
p. 2080 - 2088
(2020/02/20)

Dehydrogenation of Alcohols to Carboxylic Acid Catalyzed by in Situ-Generated Facial Ruthenium- CPP Complex
A selective catalytic system for the dehydrogenation of primary alcohols to carboxylic acids using a facial ruthenium complex generated in situ from the [Ru(COD)Cl2]n and a hybrid N-heterocyclic carbene (NHC)-phosphine-phosphine ligand (CPP) has been first reported. The facial coordination model was unveiled by NMR analysis of the reaction mixture. Such a fac-ruthenium catalyst system exhibited high catalytic activity and stability, and a high turnover number of 20 000 could be achieved with catalyst loading as low as 0.002 mol %. The exceedingly high catalyst stability was tentatively attributed to both the anchoring role of NHC and the hemi-lability of phosphines. The catalytic system also features a wide substrate scope. In particular, the facial coordination of CPP ligands was found to be beneficial for sterically hindered alcohols, and ortho-substituted benzylic alcohols and bulky adamantanyl methanol as well as cholesterol were all found to be viable dehydrogenation substrates.
Liu, Hui-Min,Jian, Lei,Li, Chao,Zhang, Chun-Chun,Fu, Hai-Yan,Zheng, Xue-Li,Chen, Hua,Li, Rui-Xiang
p. 9151 - 9160
(2019/08/12)

Bidentate Ru(ii)-NC complexes as catalysts for the dehydrogenative reaction from primary alcohols to carboxylic acids
Four Ru(ii)-NC complexes were synthesized by one-step processes from the corresponding NC ligands with RuHCl(CO)(PPh3)3. These complexes were tested as catalysts for alcohol dehydrogenative reactions, and complex {(C5H4N)-(C6H4)}RuCl(CO)(PPh3)2 (1) showed the highest activity. With KOH as the nucleophile and 0.5 mol% catalyst loading, a series of carboxylic acids were synthesized in toluene without any oxidant. Catalyst 1 could be transformed to complex {(C5H4N)-(C6H4)}RuH(CO)(PPh3)2 (6) when treated with KOH and benzyl alcohol. Complex 6 further reacted with PhCHO and H2O to generate product {(C5H4N)-(C6H4)}Ru(OCOPh)(CO)(PPh3)2 (7). Complexes 6 and 7 exhibited similar efficiency to complex 1, suggesting that they can be regarded as the catalytic intermediates of 1.
Gong, Dawei,Hu, Bowen,Chen, Dafa
p. 8826 - 8834
(2019/06/24)

Table salt as a catalyst for the oxidation of aromatic alcohols and amines to acids and imines in aqueous medium: Effectively carrying out oxidation reactions in sea water
A simple, efficient, sustainable and economical method for the oxidation of alcohols and amines has been developed based on chloride, a sea abundant anionic catalyst for the practical synthesis of a wide range of carboxylic acids, ketones and imines. Oxidation of aromatic alcohols was carried out using NaCl (20 mol%) as the catalyst, NaOH (50 mol%) and aq. TBHP (4 equiv.) as the oxidant in 55-92% isolated yields. Oxidation of aromatic amines to imines was achieved by using only 20 mol% of NaCl and aq. TBHP (4 equiv.) in 32-93% isolated yields. The chlorine species formed during the reaction as the active oxidation catalyst has been identified as ClO2- for alcohols and ClO-/ClO2- for amines by control experiments. This method is mostly free from chromatographic purification, which makes it suitable for large-scale synthesis. We have scaled up to 30 gram scale the synthesis of carboxylic acids and imines in good yields and have also carried out efficiently this new method using filtered sea water as the solvent and catalyst.
Hazra, Susanta,Kushawaha, Ajay Kishor,Yadav, Deepak,Dolui, Pritam,Deb, Mayukh,Elias, Anil J.
supporting information
p. 1929 - 1934
(2019/04/29)

Picolinamide Assisted Oxidation of CH2 Groups Bound to Organic and Organometallic Compounds Using Ferrocene as a Catalyst
Picolinamide group assisted sp3 C-H bond oxidation of methylene groups to the corresponding carbonyl compounds has been achieved by using simple bottle ferrocene as catalyst and Cu(OAc)2 or tert-butyl peroxybenzoate (TBPB) as oxidant under mild conditions. This method is applicable for picolinamide bound organic as well as organometallic compounds with yields in the range of 46-82%. Control experiments and mechanistic studies indicate that a radical mechanism is responsible for these oxidative transformations in which ferrocene acts as a catalyst.
Dolui, Pritam,Hazra, Susanta,Deb, Mayukh,Elias, Anil J.
p. 2015 - 2021
(2019/05/16)

Nickel-catalyzed carboxylation of aryl and heteroaryl fluorosulfates using carbon dioxide
The development of efficient and practical methods to construct carboxylic acids using CO2 as a C1 synthon is of great importance. Nickel-catalyzed carboxylation of aryl fluorosulfates and heteroaryl fluorosulfates with CO2 is described, affording arene carboxylic acids with good to excellent yields under mild conditions. In addition, a one-pot phenol fluorosulfation/carboxylation is developed.
Ma, Cong,Zhao, Chuan-Qi,Xu, Xue-Tao,Li, Zhao-Ming,Wang, Xiang-Yang,Zhang, Kun,Mei, Tian-Sheng
p. 2464 - 2467
(2019/04/10)

Nitrogen Dioxide Catalyzed Aerobic Oxidative Cleavage of C(OH)–C Bonds of Secondary Alcohols to Produce Acids
Stable organic nitroxyl radicals are an important class of catalysts for oxidation reactions, but their wide applications are hindered by their steric hinderance, high cost, complex operation, and separation procedures. Herein, NO2 in DMSO is shown to effectively catalyze the aerobic oxidative cleavage of C(OH)?C bonds to form a carboxylic group, and NO2 was generated in situ by decomposition of nitrates. A diverse range of secondary alcohols were selectively converted into acids in excellent yields in this transition-metal-free system without any additives. Preliminary results also indicate its applicability to depolymerize recalcitrant macromolecular lignin. Detail studies revealed that NO2 from nitrates promoted the reaction, and NO2 served as hydrogen acceptor and radical initiator for the tandem oxidative reaction.
Liu, Mingyang,Zhang, Zhanrong,Song, Jinliang,Liu, Shuaishuai,Liu, Huizhen,Han, Buxing
supporting information
p. 17393 - 17398
(2019/11/11)

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 0067; 0068

(2019/12/29)

Glycerol conversion to high-value chemicals: The implication of unnatural α-amino acid syntheses using natural resources
Glycerol derivatives are an important class of compounds, which have great applications as basic structural building blocks in organic synthesis. O-Benzylglycerol was oxidised to produce a high-value compound in high yield using a NaOtBu-O2 system. Furthermore, the synthetic utility of the resulting product was demonstrated by its transformation into unnatural α-amino acids, thus showing the valorisation of glycerol biomass.
Park, Yun Ji,Yang, Jung Woon
supporting information
p. 2615 - 2620
(2019/06/03)

Ketoreductase catalyzed stereoselective bioreduction of α-nitro ketones
We report here the stereoselective bioreduction of α-nitro ketones catalyzed by ketoreductases (KREDs) with publicly known sequences. YGL039w and RasADH/SyADH were able to reduce 23 class I substrates (1-aryl-2-nitro-1-ethanone (1)) and ten class II substrates (1-aryloxy-3-nitro-2-propanone (4)) to furnish both enantiomers of the corresponding β-nitro alcohols, with good-to-excellent conversions (up to >99%) and enantioselectivities (up to >99% ee) being achieved in most cases. To the best of our knowledge, KRED-mediated reduction of class II α-nitro ketones (1-aryloxy-3-nitro-2-propanone (4)) is unprecedented. Select β-nitro alcohols, including the synthetic intermediates of bioactive molecules (R)-tembamide, (S)-tembamide, (S)-moprolol, (S)-toliprolol and (S)-propanolol, were stereoselectively synthesized in preparative scale with 42% to 90% isolated yields, showcasing the practical potential of our developed system in organic synthesis. Finally, the advantage of using KREDs with known sequence was demonstrated by whole-cell catalysis, in which β-nitro alcohol (R)-2k, the key synthetic intermediate of hypoglycemic natural product (R)-tembamide, was produced in a space-time yield of 178 g L?1 d?1 as well as 95% ee by employing the whole cells of a recombinant E. coli strain coexpressing RasADH and glucose dehydrogenase as the biocatalyst.
Wang, Zexu,Wu, Xiaofan,Li, Zhining,Huang, Zedu,Chen, Fener
supporting information
p. 3575 - 3580
(2019/04/14)

Copper Catalyzed Oxidative C-C Bond Cleavage of 1,2-Diketones: A Divergent Approach to 1,8-Naphthalimides, Biphenyl-2,2′-dicarboxamides, and N-Heterocyclic Amides
We report here a simple and efficient copper catalyzed oxidative C-C bond cleavage of stable aromatic cyclic-fused and acyclic 1,2-diketones to deliver amides and imides in high yields. This newly developed protocol provides an excellent tool to transform structurally different 1,2-diketones into different products under the same reaction conditions. The key synthetic features of this methodology are the formation of 1,8-naphthalimides and biphenyl-2,2′-dicarboxamide motifs in high yields. The fluorescent studies of 1,8-naphthalimide derivatives were also carried out in order to show the potential application of these scaffolds.
Sakhare, Priyanka R.,Subramanian, Parthasarathi,Kaliappan, Krishna P.
p. 2112 - 2125
(2019/02/14)

A mild method for synthesizing carboxylic acids by oxidation of aldoximes using hypervalent iodine reagents
A mild oxidation method for the conversion of aldoximes to carboxylic acids was developed mediated by hypervalent iodine reagents. This method covers a wide range of functionalized aldoximes and proceeds under mild conditions, utilizing PhI(OH)OTs as an oxidant.
Nakamura, Akira,Kanou, Hodaka,Tanaka, Junki,Imamiya, Akira,Maegawa, Tomohiro,Miki, Yasuyoshi
supporting information
p. 541 - 544
(2018/02/07)

Chemoselective ester/ether C–O cleavage of methyl anisates by aluminum triiodide
The aluminum triiodide mediated chemoselective ester/ether C–O cleavage of methyl anisates was investigated. o-Anisate undergoes ether cleavage at low temperatures in carbon disulfide, cyclohexane and acetonitrile. Further cleavage of the ester group occurs at elevated temperatures to afford salicylic acid. The cleavage of p-anisate is solvent-dependent. In cyclohexane, the ester and ether groups were cleaved non-selectively to give equimolar amounts of p-anisic acid and methyl p-hydroxybenzoate. The ester group was preferentially cleaved in acetonitrile, compared to ether group cleavage in carbon disulfide. The ester cleavage reaction was improved using pyridine as an acid scavenger additive. Reasons for the contrasting reactivity of anisates towards AlI3 were explored, and the methods were applied to cleavage of the tert-butyl ester of acemetacin which gave different products under these conditions.
Sang, Dayong,Yi, Cuicui,He, Zhoujun,Wang, Jiahui,Tian, Juan,Yao, Ming,Shi, Hong
supporting information
p. 1469 - 1472
(2018/03/13)

Cobalt(III)-Catalyzed Construction of Benzofurans, Benzofuranones and One-Pot Orthogonal C?H Functionalizations to Access Polysubstituted Benzofurans
Benzofuran and benzofuranone derivatives have been synthesized through exclusive 5-exo-dig intramolecular hydroarylation using the amide-directed, cost-effective, high-valent Cp*CoIII-catalytic system. Challenging one-pot, orthogonal C?H functionalizations using two different electrophiles are also reported to afford polysubstituted benzofurans. Several valuable functional group interconversions along with removal of the amide directing group provide a route to access several diversely functionalized benzofurans. The mechanistic study suggests a reversible cobaltation step is operative here. (Figure presented.).
Bera, Sourav Sekhar,Debbarma, Suvankar,Jana, Sripati,Maji, Modhu Sudan
supporting information
p. 2204 - 2210
(2018/06/07)

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)

Sodium copper chlorophyllin catalyzed chemoselective oxidation of benzylic alcohols and diarylmethanes in water
We report the highly efficient and chemoselective oxidation of benzylic alcohols catalyzed by sodium copper chlorophyllin in water, producing corresponding arylcarbonyl compounds. Importantly, the catalytic system exhibits a wide substrate scope and high functional group tolerance. Moreover, secondary alcohols and even diarylmethanes were smoothly oxidized to the desired aryl ketones with excellent yields.
Liu, Shi-juan,Zhang, Miao,Lu, Rong,Li, Xiu-ying,Che, Guang-bo
(2018/08/17)

A Highly Efficient NHC-Catalyzed Aerobic Oxidation of Aldehydes to Carboxylic Acids
An N-heterocyclic carbene (NHC) organocatalytic aerobic oxidation of aldehydes to the corresponding carboxylic acids is explored. Remarkably, this method allows for efficient conversion of different classes of aldehydes including highly challenging electron-rich aryl aldehydes, ortho -substituted aryl aldehydes, various heteroaromatic aldehydes and α,β-unsaturated aldehydes under mild reaction conditions. These substrates, under previously reported NHC-catalyzed methods, are typically unreactive or give poor yields, require high reaction temperatures and reaction times of several days.
Khatana, Anil Kumar,Singh, Vikram,Gupta, Manoj Kumar,Tiwari, Bhoopendra
p. 4290 - 4294
(2018/11/23)

Transition-metal-free conversion of lignin model compounds to high-value aromatics: Scope and chemoselectivity
An efficient and straightforward reaction protocol for the conversion of lignin model compounds was developed based on a simple system consisting of a base, oxygen, and a green solvent under mild conditions in the absence of metals. This protocol was successfully applied to the cleavage of both 'β-O-4' dimeric and trimeric compounds, and a controlled selective degradation was achieved depending on the bond type. The feasibility of this method to provide aromatic compounds in high yields from lignin by a sequential oxidative dehomologation reaction was clearly demonstrated.
Lee, Tae Woo,Yang, Jung Woon
p. 3761 - 3771
(2018/08/21)

A biocatalytic method for the chemoselective aerobic oxidation of aldehydes to carboxylic acids
Herein, we present a study on the oxidation of aldehydes to carboxylic acids using three recombinant aldehyde dehydrogenases (ALDHs). The ALDHs were used in purified form with a nicotinamide oxidase (NOx), which recycles the catalytic NAD+ at the expense of dioxygen (air at atmospheric pressure). The reaction was studied also with lyophilised whole cell as well as resting cell biocatalysts for more convenient practical application. The optimised biocatalytic oxidation runs in phosphate buffer at pH 8.5 and at 40 °C. From a set of sixty-one aliphatic, aryl-Aliphatic, benzylic, hetero-Aromatic and bicyclic aldehydes, fifty were converted with elevated yield (up to >99%). The exceptions were a few ortho-substituted benzaldehydes, bicyclic heteroaromatic aldehydes and 2-phenylpropanal. In all cases, the expected carboxylic acid was shown to be the only product (>99% chemoselectivity). Other oxidisable functionalities within the same molecule (e.g. hydroxyl, alkene, and heteroaromatic nitrogen or sulphur atoms) remained untouched. The reaction was scaled for the oxidation of 5-(hydroxymethyl)furfural (2 g), a bio-based starting material, to afford 5-(hydroxymethyl)furoic acid in 61% isolated yield. The new biocatalytic method avoids the use of toxic or unsafe oxidants, strong acids or bases, or undesired solvents. It shows applicability across a wide range of substrates, and retains perfect chemoselectivity. Alternative oxidisable groups were not converted, and other classical side-reactions (e.g. halogenation of unsaturated functionalities, Dakin-Type oxidation) did not occur. In comparison to other established enzymatic methods such as the use of oxidases (where the concomitant oxidation of alcohols and aldehydes is common), ALDHs offer greatly improved selectivity.
Knaus, Tanja,Tseliou, Vasilis,Humphreys, Luke D.,Scrutton, Nigel S.,Mutti, Francesco G.
supporting information
p. 3931 - 3943
(2018/09/11)

Continuous Platform to Generate Nitroalkanes On-Demand (in Situ) Using Peracetic Acid-Mediated Oxidation in a PFA Pipes-in-Series Reactor
The synthetic utility of the aza-Henry reaction can be diminished on scale by potential hazards associated with the use of peracid to prepare nitroalkane substrates and the nitroalkanes themselves. In response, a continuous and scalable chemistry platform to prepare aliphatic nitroalkanes on-demand using the oxidation of oximes with peracetic acid and direct reaction of the nitroalkane intermediate in an aza-Henry reaction is reported. A uniquely designed pipes-in-series plug-flow tube reactor addresses a range of process challenges, including stability and safe handling of peroxides and nitroalkanes. The subsequent continuous extraction generates a solution of purified nitroalkane, which can be directly used in the following enantioselective aza-Henry chemistry to furnish valuable chiral diamine precursors with high selectivity, thus completely avoiding isolation of the potentially unsafe low-molecular-weight nitroalkane intermediate. A continuous campaign (16 h) established that these conditions were effective in processing 100 g of the oxime and furnishing 1.4 L of nitroalkane solution.
Tsukanov, Sergey V.,Johnson, Martin D.,May, Scott A.,Kolis, Stanley P.,Yates, Matthew H.,Johnston, Jeffrey N.
p. 971 - 977
(2018/08/28)

Pd-Catalyzed debenzylation and deallylation of ethers and esters with sodium hydride
Herein we demonstrate simply that the addition of Pd(OAc)2 as a promotor switches the reactivity of a commonly used base NaH to a nucleophilic reductant. The reactivity is engineered into a palladium-catalyzed reductive debenzylation and deallylation of aryl ethers and esters. This operationally simple, mild protocol displays a broad substrate scope and a broad spectrum of functional group tolerance (>50 examples) and high chemoselectivity toward aryl ethers over aliphatic structures. Moreover, the dual reactivity of NaH as a base and a reductant is demonstrated in efficient synthetic elaboration.
Mao, Yujian,Liu, Ye,Hu, Yanwei,Wang, Liang,Zhang, Shilei,Wang, Wei
p. 3016 - 3020
(2018/04/14)

Application of metallide/palladium compound catalytic reduction system in reaction of removing allyl groups and deuteration reaction
The invention discloses application of a metallide/palladium compound catalytic reduction system in reaction of removing allyl groups of a compound containing the allyl groups and deuteration reaction. The reaction comprises the following steps: under protection of nitrogen gas, suspending a palladium compound and a metallide in a solvent, stirring for 5 minutes, adding the compound containing theallyl groups, reacting for 0.5-36 hours at the temperature of minus 50-120 DEG C, adding ice water to stop reaction, regulating a pH value to 3.5 by using diluted hydrochloric acid, and carrying outsolvent extraction, drying by steaming and column-chromatography purification on reaction liquid to finish the reaction.
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Paragraph 0044

(2018/07/30)

Enzymatic chemical transformations of aldehydes, ketones, esters and alcohols using plant fragments as the only biocatalyst: Ximenia americana grains
The present study demonstrated the ability of Ximenia american as a biocatalyst in reduction, hydrolysis and esterification reactions. The reduction reactions of aldehydes and ketones, ester hydrolysis and esterification of alcohols were carried out with interesting results. Reduction of ketones afforded yields of 6–60% with ee in the range of 35–>99% and that of aldehydes in yields of 51–99%. On the other hand, ester hydrolysis afforded yields of 58–98% with ee in the range 34–87%, while esterification of alcohols in 18–99% yields. Experimental conditions for all reactions have been defined using standard substrates as indicated in results and discussion. Some of the products are the potential building blocks for the synthesis of molecules which are of pharmaceutical and agrochemical importance.
da Silva, Romézio Alves Carvalho,de Mesquita, Bruna Marques,de Farias, Iolanda Frota,do Nascimento, Patrícia Georgiana Garcia,de Lemos, Telma Leda Gomes,Queiroz Monte, Francisco José
p. 187 - 194
(2018/01/05)

Method for preparing aryl formic acid compound with microchannel continuous flow reactor
The invention discloses a method for preparing an aryl formic acid compound with a microchannel continuous flow reactor. The method comprises the following steps: with methyl aromatics represented bythe formula (I) as a raw material, a mixture of cobalt salt, manganese salt and iron salt as a ternary complex catalyst, hydrogen peroxide with mass concentration of 30% as a cocatalyst, and acetonitrile or acetic acid as an organic solvent, uniformly mixing to form a homogeneous solution, pumping the homogeneous solution into the microchannel continuous flow reactor through a metering pump, reacting at 25 to 150 DEG C in an oxygen atmosphere of 0.5 to 10 MPa for 4 to 100 seconds to obtain a reaction mixture, and carrying out post-treatment to obtain the aryl formic acid compound represented by the formula (II). According to the invention, with cleaning agents such as oxygen and hydrogen peroxide as oxidants and cocatalysts, by-products toxic and harmful to the environment are reduced, thesystem is greener and cleaner, the reaction can be continuously carried out, the production efficiency is high, and industrialized amplified production is facilitated.
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Paragraph 0033; 0034; 0035

(2018/11/03)

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)