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On the possible causes of enhancement of the heterogeneous catalytic liquid-phase oxidation reaction of m-xylene by microwave radiation
The contribution of the heterogeneous component of the total conversion of m-xylene to the process of its heterogeneous catalytic liquid-phase oxidation has been studied, as this contribution is most clearly manifested in the case of microwave treatment. It has been shown that microwave irradiation shortens the induction period of the reaction taken to reach a steady state. It has been suggested that the observed increase in the generation rate of free m-xylyl radicals by microwave treatment is due to the appearance at the hydrocarbons/catalyst interface of local overheating regions whose temperature can exceed the weight-average temperature in the reaction space.
Litvishkov,Tret'Yakov,Talyshinskii,Shakunova,Zul'Fugarova,Mardanova,Nagdalieva
p. 117 - 120
(2013)
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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)

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)

An Anionic, Chelating C(sp3)/NHC ligand from the Combination of an N-heterobicyclic Carbene and Barbituric Heterocycle
The coordination chemistry of the anionic NHC1-based on an imidazo[1,5-a]pyridin-3-ylidene (IPy) platform substituted at the C5 position by an anionic barbituric heterocycle was studied with d6(Ru(II), Mn(I)) and d8(Pd(II), Rh(I), Ir(I), Au(III)) transition-metal centers. While the anionic barbituric heterocycle is planar in the zwitterionic NHC precursor 1·H, NMR spectroscopic analyses supplemented by X-ray diffraction studies evidenced the chelating behavior of ligand 1-through the carbenic and the malonic carbon atoms in all of the complexes, resulting from a deformation of the lateral barbituric heterocycle. The complexes were obtained by reaction of the free carbene with the appropriate metal precursor, except for the Au(III) complex 10, which was obtained by oxidation of the antecedent gold(I) complex [AuCl(1)]?with PhICl2as an external oxidant. During the course of the process, the kinetic gold(I) intermediate 9 resulting from the oxidation of the malonic carbon of the barbituric moiety was isolated upon crystallization from the reaction mixture. The νCOstretching frequencies recorded for complex [Rh(1)(CO)2] (5) demonstrated the strong donating character of the malonate-C(sp3)/NHC ligand 1-. The ruthenium complex [Ru(1)Cl(p-cymene)] (11) was implemented as a precatalyst in the dehydrogenative synthesis of carboxylic acid derivatives from primary alcohols and exhibited high activities at low catalyst loadings (25-250 ppm) and a large tolerance toward functional groups.
Benaissa, Idir,Gajda, Katarzyna,Vendier, Laure,Lugan, No?l,Kajetanowicz, Anna,Grela, Karol,Michelet, Véronique,César, Vincent,Bastin, Stéphanie
supporting information
p. 3223 - 3234
(2021/09/30)

Cleavage of Carboxylic Esters by Aluminum and Iodine
A one-pot procedure for deprotecting carboxylic esters under nonhydrolytic conditions is described. Typical alkyl carboxylates are readily deblocked to the carboxylic acids by the action of aluminum powder and iodine in anhydrous acetonitrile. Cleavage of lactones affords the corresponding ω-iodoalkylcarboxylic acids. Aryl acetylates undergo deacetylation with the participation of the neighboring group. This method enables the selective cleavage of alkyl carboxylic esters in the presence of aryl esters.
Sang, Dayong,Yue, Huaxin,Fu, Yang,Tian, Juan
p. 4254 - 4261
(2021/03/09)

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.
Hayashi, Kazuhiko,Ichimaru, Yoshimi,Sugiura, Kirara,Maeda, Azusa,Harada, Yumi,Kojima, Yuki,Nakayama, Kanae,Imai, Masanori
p. 581 - 594
(2021/06/06)

Isotruxene-based porous polymers as efficient and recyclable photocatalysts for visible-light induced metal-free oxidative organic transformations
Two new isotruxene-based porous polymers were prepared and demonstrated to be highly efficient, metal-free heterogeneous photocatalysts for oxidative transformations using air as the mild oxidant under visible-light irradiation. Both catalysts show excellent recyclability. In addition, the reactions can be performed in water, further indicating the greenness of this method. This journal is
Zhang, Haowen,Zhang, Xiao,Zheng, Ying,Zhou, Cen
supporting information
p. 8878 - 8885
(2021/11/27)

MOF-Zn-NHC as an efficient N-heterocyclic carbene catalyst for aerobic oxidation of aldehydes to their corresponding carboxylic acids: Via a cooperative geminal anomeric based oxidation
As an efficient heterogenous N-heterocyclic carbene (NHC) catalyst, MOF-Zn-NHC was used in the aerobic oxidation of aryl aldehydes to their corresponding carbocyclic acids via an anomeric based oxidation. Features such as mild reaction conditions and no need for a co-catalyst or oxidative reagent can be considered as the major advantages of the presented method in this study. This journal is
Babaee, Saeed,Zarei, Mahmoud,Zolfigol, Mohammad Ali
p. 36230 - 36236
(2021/12/02)

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)

Ferric ion concentration-controlled aerobic photo-oxidation of benzylic C–H bond with high selectivity and conversion
A Fe(III)-promoted highly selective photo-oxidation of benzylic C–H bond delivering relative carbonyl products is reported. By altering the concentration of ferric salt, methylarenes can be selectively oxidized under UV irradiation to furnish aromatic aldehydes or acids, respectively. By this protocol, the oxidation of ethylarenes provides the corresponding acetophenones. The reaction is inferred to involve divergent pathways in different concentrations of catalyst for the alternative selectivity between aldehydes and aicds. The reusable catalyst, high conversion and selectivity make this oxidation a green and economic protocol for the synthesis of aromatic carbonyl compounds.
Bu, Hongzhong,Gu, Jiefan,Li, Yufeng,Ma, Hongfei,Wan, Yuting,Wu, Zheng-Guang,Zhang, Weijian,Zhou, Ying'ao,Zhu, Hongjun
(2021/07/16)

Bimetallic oxide nanoparticles confined in ZIF-67-derived carbon for highly selective oxidation of saturated C–H bond in alkyl arenes
Zeolite imidazolate frameworks (ZIFs) have recently emerged as an ideal type of carbon precursors with abundant tailorability. In this work, a series of ZIF-derived porous carbon catalysts have been prepared with encapsulation of bimetallic oxide nanoparticles via simple thermal treatment. The composition and structure of these catalysts were confirmed in detail by different characterization methods. The bimetallic oxide (Mn/Co, Fe/Co, and Cu/Co) nanoparticles were encapsulated in the nitrogen-doped graphitized carbon matrix. Moreover, the hierarchically porous structure and carbon defects were successfully constructed in the carbon catalysts. Additionally, in the selective oxidation of saturated C–H bonds in alkyl arenes, the carbon catalysts demonstrate outstanding performance for the oxidation of C–H bonds to corresponding carboxyl groups. This was due to their unique structure can greatly promote mass transfer and molecular oxygen activation, resulting in high conversion and high selectivity. Remarkably, this work here could also provide a novel strategy to the controllable synthesis of metal–organic frameworks (MOFs)-derived carbon catalysts for enhanced performance in heterogeneous catalysis.
Huang, Cheng,Su, Xiaoyan,Gu, Xiangyu,Liu, Rui,Zhu, Hongjun
(2020/10/15)

Atomically Dispersed Co Clusters Anchored on N-doped Carbon Nanotubes for Efficient Dehydrogenation of Alcohols and Subsequent Conversion to Carboxylic Acids
The catalytic dehydrogenation of readily available alcohols to high value-added carbonyl compounds is a research hotspot with scientific significance. Most of the current research about this reaction is performed with noble metal-based homogeneous catalysts of high price and poor reusability. Herein, highly dispersed Co-cluster-decorated N-doped carbon nanotubes (Co/N-CNTs) were fabricated via a facile strategy and used for the dehydrogenation of alcohols with high efficiency. Various characterization techniques confirmed the presence of metallic Co clusters with almost atomic dispersion, and the N-doped carbon supports also enhanced the catalytic activity of Co clusters in the dehydrogenation reaction. Aldehydes as dehydrogenation products were further transformed in situ to carboxylic acids through a Cannizzaro-type pathway under alkaline conditions. The reaction pathway of the dehydrogenation of alcohols was clearly confirmed by theoretical calculations. This work should provide an effective and simple approach for the accurate design and synthesis of small Co-clusters catalysts for the efficient dehydrogenation-based transformation of alcohols to carboxylic acids under mild reaction conditions.
Dong, Zhengping,Fang, Jian,Li, Boyang,Xu, Dan,Zhang, Fengwei,Zhao, Hong,Zhu, Hanghang
p. 4536 - 4545
(2021/09/22)

Method for coproducing methyl benzoic acid Process for the production of methyl benzoates and diesters of phthalic acids
The invention discloses a coproduction method of methylbenzoic acid, methyl benzoate and benzenedicarboxylic acid diester. The method comprises the following steps: (1) continuously introducing xylene, a catalyst and oxygen-containing gas into an oxidation reactor for a reaction, and controlling oxygenic concentration in the tail gas to not exceed 5% by controlling introduction amount of the oxygen-containing gas to obtain an oxidation reaction liquid; (2) feeding the obtained oxidation reaction liquid into a predistillation tower for distillation separation to obtain a low-boiling-point component and a predistillation tower bottom liquid; (3) feeding the predistillation tower bottom liquid into a distillation tower for distillation to obtain a methylbenzoic acid product and a distillationtower bottom liquid; (4) mixing the distillation tower bottom liquid and alcohol for an esterification reaction, and controlling the reaction endpoint to be lower than 0.5wt% of the content of methylbenzoic acid to obtain an esterification reaction liquid; (5) performing distillation separation on the obtained esterification reaction liquid to obtain methyl benzoate and benzenedicarboxylic acid diester products. The method has the advantages that the process is simple, equipment investment is low, and the method is environmentally friendly and has good comprehensive economic benefits.
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Paragraph 0125-0175

(2021/02/09)

Hydrolysis of amides to carboxylic acids catalyzed by Nb2O5
Hydrolysis of amides to carboxylic acids is an industrially important reaction but is challenging due to the difficulty of cleaving the resonance stabilized amidic C-N bond. Twenty-three heterogeneous and homogenous catalysts were examined in the hydrolysis of acetamide. Results showed that Nb2O5was the most effective heterogeneous catalyst with the greatest yield of acetic acid. A series of Nb2O5catalysts calcined at various temperatures were characterized and tested in the hydrolysis of acetamide to determine the effects of crystal phase and surface properties of Nb2O5on catalytic performance. The high catalytic performance observed was attributed mainly to the facile activation of the carbonyl bond by Lewis acid sites that function even in the presence of basic inhibitors (NH3and H2O). The catalytic studies showed the synthetic advantages of the present method, such as simple operation, catalyst recyclability, additive free, solvent free, and wide substrate scope (>40 examples; up to 95% isolated yield).
Siddiki,Rashed, Md. Nurnobi,Touchy, Abeda Sultana,Jamil, Md. A. R.,Jing, Yuan,Toyao, Takashi,Maeno, Zen,Shimizu, Ken-Ichi
p. 1949 - 1960
(2021/03/26)

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)

Selective oxidation of alkenes to carbonyls under mild conditions
Herein, a practical and sustainable method for the synthesis of aldehydes, ketones, and carboxylic acids from an inexpensive olefinic feedstock is described. This transformation features very sustainable and mild conditions and utilizes commercially available and inexpensive tetrahydrofuran as the additive, molecular oxygen as the sole oxidant and water as the solvent. A wide range of substituted alkenes were found to be compatible, providing the corresponding carbonyl compounds in moderate-to-good yields. The control experiments demonstrated that a radical mechanism is responsible for the oxidation reaction.
Huo, Jie,Xiong, Daokai,Xu, Jun,Yue, Xiaoguang,Zhang, Pengfei,Zhang, Yilan
supporting information
p. 5549 - 5555
(2021/08/16)

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)

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)

Clean and Selective Oxidation of Alcohols with Oxone and Phase-Transfer Catalysts in Water
Abstract: A new, simple, metal-free, and eco-friendly procedure has been proposed forthe oxidation of alcohols with Oxone (potassium peroxymonosulfate) in water inthe presence of six phase-transfer catalysts (PTC). Phase-transfer catalystswere found to display high catalytic activity in water solution. Furthermore,the oxidation of alcohols was also carried out with relatively good conversionand selectivity in water without any catalyst.
An, X. Q.,Kang, M.,Ma, H. C.,Yang, Y. X.,Yang, Z. W.,Zeng, W.
p. 1790 - 1794
(2020/12/01)

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)

Nickel-Catalyzed Conversion of Amides to Carboxylic Acids
We report the conversion of amides to carboxylic acids using nonprecious metal catalysis. The methodology strategically employs a nickel-catalyzed esterification using 2-(trimethylsilyl)ethanol, followed by a fluoride-mediated deprotection in a single-pot operation. This approach circumvents catalyst poisoning observed in attempts to directly hydrolyze amides using nickel catalysis. The selectivity and mildness of this transformation are shown through competition experiments and the net-hydrolysis of a complex valine-derived substrate. This strategy addresses a limitation in the field with regard to functional groups accessible from amides using transition metal-catalyzed C-N bond activation and should prove useful in synthetic applications.
Bulger, Ana S.,Garg, Neil K.,Knapp, Rachel R.
(2020/04/02)

Deep eutectic solvent-catalyzed Meyer-Schuster rearrangement of propargylic alcohols under mild and bench reaction conditions
The Meyer-Schuster rearrangement of propargylic alcohols into α,β-unsaturated carbonyl compounds has been revisited by setting up an atom-economic process catalyzed by a deep eutectic solvent FeCl3·6H2O/glycerol. Isomerizations take place smoothly, at room temperature, under air and with short reaction times. The unique solubilizing properties of the eutectic mixture enabled the use of a substrate concentration up to 1.0 M with the medium being recycled up to ten runs without any loss of catalytic activity. This journal is
Ríos-Lombardía, Nicolás,Cicco, Luciana,Yamamoto, Kota,Hernández-Fernández, José A.,Morís, Francisco,Capriati, Vito,García-álvarez, Joaquín,González-Sabín, Javier
supporting information
p. 15165 - 15168
(2020/12/21)

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 0022-0023

(2020/05/30)

Pd(OAc)2 promoted bis-N-heterocyclic carbene-catalyzed oxidative transformation of aldehydes
The bis-N-heterocyclic carbene-catalyzed (bis-NHC-catalyzed) oxidative transformation of aldehydes was successfully studied in water under air. The reaction rate increased through the use of Pd(OAc)2 as an additive. Notably, the catalytic system exhibited good tolerance toward aliphatic and aromatic aldehydes bearing halide and alkyl functional groups. In addition, gram-scale reaction was also tested in this study. The use of water and operational simplicity make this methodology environmentally benign and cost-effective.
Yu, Ya-Han,Wang, Tsui,Chiu, Chien-Cheng,Lu, Ta-Jung,Lee, Dong-Sheng
p. 202 - 205
(2019/11/28)

Sequential Connection of Mutually Exclusive Catalytic Reactions by a Method Controlling the Presence of an MOF Catalyst: One-Pot Oxidation of Alcohols to Carboxylic Acids
A functionalized metal-organic framework (MOF) catalyst applied to the sequential one-pot oxidation of alcohols to carboxylic acids controls the presence of a heterogeneous catalyst. The conversion of alcohols to aldehydes was acquired through aerobic oxidation using a well-known amino-oxy radical-functionalized MOF. In the same flask, a simple filtration of the radical MOF with mild heating of the solution completely altered the reaction media, providing radical scavenger-free conditions suitable for the autoxidation of the aldehydes formed in the first step to carboxylic acids. The mutually exclusive radical-catalyzed aerobic oxidation (the first step with MOF) and radical-inhibited autoxidation (the second step without MOF) are sequentially achieved in a one-pot manner. Overall, we demonstrate a powerful and efficient method for the sequential oxidation of alcohols to carboxylic acids by employing a readily functionalizable heterogeneous MOF. In addition, our MOF in-and-out method can be utilized in an environmentally friendly way for the oxidation of alcohols to carboxylic acids of industrial and economic value with broad functional group tolerance, including 2,5-furandicarboxylic acid and 1,4-benzenedicarboxylic acid, with good yield and reusability. Furthermore, MOF-TEMPO, as an antioxidative stabilizer, prevents the undesired oxidation of aldehydes, and the perfect "recoverability"of such a reactive MOF requires a re-evaluation of the advantages of MOFs from heterogeneity in catalytic and related applications.
Kim, Seongwoo,Lee, Ha-Eun,Suh, Jong-Min,Lim, Mi Hee,Kim, Min
supporting information
p. 17573 - 17582
(2020/12/22)

Catalytic C-H aerobic and oxidant-induced oxidation of alkylbenzenes (including toluene derivatives) over VO2+immobilized on core-shell Fe3O4?SiO2at room temperature in water
Direct C-H bond oxidation of organic materials, and producing the necessary oxygenated compounds under mild conditions, has attracted increasing interest. The selective oxidation of various alkylbenzenes was carried out by means of a new catalyst containing VO2+ species supported on silica-coated Fe3O4 nanoparticles using t-butyl hydroperoxide as an oxidant at room temperature in H2O or solvent-free media. The chemical and structural characterization of the catalyst using several methods such as FTIR spectroscopy, XRD, FETEM, FESEM, SAED, EDX and XPS showed that VO2+ is covalently bonded to the silica surface. High selectivity and excellent conversion of various toluene derivatives, with less reactive aliphatic (sp3) C-H bonds, to related benzoic acids were quite noticeable. The aerobic oxygenation reaction of these alkylbenzenes was studied under the same conditions. All the results accompanied by sustainability of the inexpensive and simple magnetically separable heterogeneous catalyst proved the important criteria for commercial applications. This journal is
Mohammadpour, Pegah,Safaei, Elham
p. 23543 - 23553
(2020/07/14)

Reaction method for selectively synthesizing aromatic aldehyde or aromatic carboxylic acid
The invention provides a reaction method for selectively synthesizing aromatic aldehyde or aromatic carboxylic acid. Toluene aromatic hydrocarbon without substituent or with substituent on a benzene ring is used as a raw material, an inorganic salt of ferric iron is used as a catalyst, air or oxygen is used as an oxidizing agent, a mixed solution of acetonitrile and water is used as a solvent, theraw material is oxidized by adjusting the dosage of the catalyst to obtain aromatic aldehyde or aromatic carboxylic acid, and the aromatic aldehyde or aromatic carboxylic acid is irradiated by ultraviolet light for 10-16 hours. Aromatic carboxylic acid obtained under the condition that the dosage of the catalyst is 5-50% mol of aromatic hydrocarbon is used as a main product, wherein the use amount of the catalyst is 70-200% mol of aromatic hydrocarbon. The reaction method provided by the invention has the characteristics of atom economy and high selectivity, uses the metal iron salt with richearth content for catalysis, and has the advantages of mild conditions, recyclable catalyst and solvent and the like.
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Paragraph 0031-0032

(2020/12/05)

Preparation method of 3-carboxybenzaldehyde
The invention discloses a preparation method of 3-carboxybenzaldehyde. The method comprises the following steps: by using m-toluonitrile as a starting raw material, carrying out a first hydrolysis reaction, and adding an acid to carry out an acidification reaction to obtain m-toluic acid; carrying out chlorination reaction on m-toluic acid to obtain 3-carboxyl benzyl chloride; mixing the 3-carboxyl benzyl chloride and urotropin for an oxidation reaction, then adding glacial acetic acid and water for a second hydrolysis reaction to obtain the 3-carboxybenzaldehyde. According to the method disclosed by the invention, m-toluonitrile with low cost is used as a raw material, the 3-carboxybenzaldehyde is synthesized through a series of processes of hydrolysis, chlorination, oxidation and hydrolysis, and the product purity and yield are relatively high; the method has the advantages of simple and safe process operation, easily available raw materials and low cost and is suitable for industrial production.
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Paragraph 0040-0041; 0045-0046; 0050-0051

(2020/04/29)

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)

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)

Nanosheet-assembled microflower-like coordination polymers by surfactant-assisted assembly with enhanced catalytic activity
Tuning the morphology and size of coordination polymers (CPs) is an effective strategy to enable crystalline materials for desired applications. Herein, two CPs, named [Cd2(DBTP)(H2O)2]n (1) and {[Zn2(DBTP)(H2O)]·2.5H2O}n (2), were prepared by employing a rigid V-shaped and multidentate N-heterocyclic ligand 2,6-di(1H,2′H-[3,3′-bi(1,2,4-triazol)]-5′-yl)pyridine (H4DBTP) under solvothermal conditions. Their crystal morphologies and sizes were controlled by varying the type and the amount of surfactants. The morphology can be changed from bulk blocks to microflower-like hierarchical spheres assembled by nanosheets and the mean size of the microflowers is approximately 2 μm. Nanoscale 1a and 2a were further evaluated as heterogeneous catalysts for the conversion reactions of nitromethylbenzenes into benzoic acids. The results showed that nanoscale 2a is a more efficient catalyst than nanoscale 1a and their corresponding bulk counterparts.
Han, Suzhen,Hu, Mingjun,Huang, Chao,Lu, Guizhen,Mi, Liwei,Qin, Na,Zhang, Ying-Ying,Zhu, Kaifang
p. 7858 - 7863
(2020/12/04)

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)

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)

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)

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)

Ni-Catalyzed Carboxylation of C(sp2)-S Bonds with CO2: Evidence for the Multifaceted Role of Zn
Nickel-catalyzed reductive carboxylation reactions of aryl electrophiles typically require the use of metallic reducing agents. At present, the prevailing perception is that these serve as both a source of electrons and as a source of Lewis acids that may aid CO2 insertion into the Ni-C bond. Herein, we provide evidence for the in situ formation of organometallic species from the metallic reductant, a step that has either been ruled out or has been unexplored in catalytic carboxylation reactions with metal powder reductants. Specifically, we demonstrate that Zn(0) acts as a reductant and that Zn(II) generates arylzinc species that might play a role in the C(sp2)-S carboxylation of arylsulfonium salts. Overall, the reductive Ni-catalyzed C(sp2)-S carboxylation reaction proceeds under mild conditions in a non-amide solvent, displays a wide substrate scope, and can be applied to the formal para C-H carboxylation of arenes.
Yanagi, Tomoyuki,Somerville, Rosie J.,Nogi, Keisuke,Martin, Ruben,Yorimitsu, Hideki
p. 2117 - 2123
(2020/02/28)

Selective Solvent-Free and Additive-Free Oxidation of Primary Benzylic C–H Bonds with O2 Catalyzed by the Combination of Metalloporphyrin with N-Hydroxyphthalimide
Abstract: A protocol for solvent-free and additive-free oxidation of primary benzylic C–H bonds with O2 was presented through adjusting the combination of metalloporphyrins and NHPI as binary catalysts to overcome the deficiencies encountered in current oxidation systems. The effects of reaction temperature, porphyrin structure, central metal, catalyst loading and O2 pressure were investigated systematically. For the optimized combination of T(2-OCH3)PPCo and NHPI, all the primary benzylic C–H bonds could be functionalized efficiently and selectively at 120 °C and 1.0?MPa O2 with aromatic acids as the primary products. The selectivity towards aromatic acids could reach up to 70–95% in the conversion of more than 30% for most of the substrates possessing primary benzylic C–H bonds in the metalloporphyrin loading of 0.012% (mol/mol). And the superior performance of T(2-OCH3)PPCo among the metalloporphyrins investigated was mainly attributed to its high efficiency in charge transfer and fewer positive charges around central metal Co (II) which favored the adduction of O2 to cobalt (II) forming the high-valence metal-oxo complex followed by the production of phthalimide N-oxyl radical (PINO) and the initiation of the catalytic oxidation cycle. This work would provide not only an efficient protocol in utilization of hydrocarbons containing primary benzylic C–H bonds, but also a significant reference in the construction of more efficient C–H bonds oxidation systems. Graphic Abstract: The solvent-free and additive-free oxidation of primary benzylic C–H bonds with O2 was presented through adjusting the combination of metalloporphyrins and NHPI as binary catalysts, and the highest selectivity towards aromatic acid reached up to 95.1% with the conversion of 88.5% in the optimized combination of T(2-OCH3)PPCo and NHPI.[Figure not available: see fulltext.].
Shen, Hai-Min,Qi, Bei,Hu, Meng-Yun,Liu, Lei,Ye, Hong-Liang,She, Yuan-Bin
p. 3096 - 3111
(2020/04/29)

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; 0129-0134; 0271-0272

(2020/05/01)

Magnesiation of Aryl Fluorides Catalyzed by a Rhodium-Aluminum Complex
We report the magnesiation of aryl fluorides catalyzed by an Al-Rh heterobimetallic complex. We show that the complex is highly reactive to cleave the C-F bonds across the polarized Al-Rh bond under mild conditions. The reaction allows the use of an easy-to-handle magnesium powder to generate a range of arylmagnesium reagents from aryl fluorides, which are conventionally inert to such metalation compared with other aryl halides.
Fujii, Ikuya,Semba, Kazuhiko,Li, Qiao-Zhi,Sakaki, Shigeyoshi,Nakao, Yoshiaki
supporting information
p. 11647 - 11652
(2020/08/06)

Aqueous Flow Hydroxycarbonylation of Aryl Halides Catalyzed by an Amphiphilic Polymer-Supported Palladium-Diphenylphosphine Catalyst
An aqueous continuous-flow reaction system is developed for the palladium-catalyzed hydroxycarbonylation of aryl halides. Flow hydroxycarbonylation of aryl halides in aqueous solution proceeds efficiently in a flow reactor containing a palladium-diphenylphosphine complex immobilized on an amphiphilic polystyrene-poly(ethylene glycol) resin to give the corresponding benzoic acids in excellent yields.
Osako, Takao,Kaiser, Reinhard,Torii, Kaoru,Uozumi, Yasuhiro
p. 961 - 966
(2019/05/10)

Aerobic Co-/ N-Hydroxysuccinimide-Catalyzed Oxidation of p-Tolylsiloxanes to p-Carboxyphenylsiloxanes: Synthesis of Functionalized Siloxanes as Promising Building Blocks for Siloxane-Based Materials
Synthesis of organosilicon products with a "polar" functional group within organic substituents is one of the most fundamentally and practically important challenges in today's chemistry of silicones. In our study, we suggest a solution to this problem, viz., a high-efficiency preparative method based on aerobic Co-/N-hydroxysuccinimide (NHSI) catalyzed oxidation of p-tolylsiloxanes to p-carboxyphenylsiloxanes. This approach is based on "green", commercially available, simple, and inexpensive reagents and employs mild reaction conditions: Co(OAc)2/NHSI catalytic system, O2 as the oxidant, process temperature from 40 to 60 °C, atmospheric pressure. This reaction is general and allows for synthesizing both mono- and di-, tri-, and poly(p-carboxyphenyl)siloxanes with p-carboxyphenyl groups at 1,1-, 1,3-, 1,5-, and 1,1,1-positions. All the products were obtained and isolated in gram amounts (up to 5 g) and in high yields (80-96%) and characterized by NMR, ESI-HRMS, GPC, IR, and X-ray data: p-carboxyphenylsiloxanes in crystalline state form HOF-like structures. Furthermore, it was shown that the suggested method is applicable for the oxidation of organic alkylarene derivatives (Ar-CH3, Ar-CH2-R) to the corresponding acids and ketones (Ar-C(O)OH and Ar-C(O)-R), as well as hydride silanes ([Si]-H) to silanols ([Si]-OH). The possibility of synthesizing monomeric (methyl) and polymeric (siloxane-containing PET analogue, Sila-PET) esters based on 1,3-bis(p-carboxyphenyl)disiloxane was studied. These processes occur with retention of the organosiloxane frame and allow to obtain the corresponding products in 90 and 99% yields.
Goncharova, Irina K.,Silaeva, Kseniia P.,Arzumanyan, Ashot V.,Anisimov, Anton A.,Milenin, Sergey A.,Novikov, Roman A.,Solyev, Pavel N.,Tkachev, Yaroslav V.,Volodin, Alexander D.,Korlyukov, Alexander A.,Muzafarov, Aziz M.
supporting information
p. 2143 - 2151
(2019/02/05)

N-Doped carbon nanofibers derived from bacterial cellulose as an excellent metal-free catalyst for selective oxidation of arylalkanes
N-Doped carbon nanofibers derived from one-step pyrolysis of low-cost bacterial cellulose with the assistance of urea were reported. Owing to their interconnected nanofibrous structure and high specific surface area as well as high N doping, they exhibited excellent catalytic performance for selective oxidation of arylalkanes even with O2 as an oxidant in aqueous solution.
Huang, Runkun,Cao, Changyan,Liu, Jian,Sun, Dongping,Song, Weiguo
supporting information
p. 1935 - 1938
(2019/05/02)

The sustainable room temperature conversion of: P -xylene to terephthalic acid using ozone and UV irradiation
Current industrial processes utilize Co/Mn bromides as catalysts to catalyze the oxidative conversion of para-xylene to terephthalic acid (TA) in acetic acid at high temperatures (>200 °C, air, 15-30 atm.). The decomposition of metallo-catalysts and solvents at high temperatures as well as a subsequent hydropurification process releases thousands of millions of tons of wastewater, global warming gas (CO2) and ozone depleting gas (CH3Br) into the global environment per year, causing global warming, ozone depletion, dramatic climate change, huge economic losses, and many other environmental problems. Herein, we report an alternative sustainable process with low energy demand for the room temperature oxidative conversion of p-xylene to terephthalic acid, with 96% TA yield and 98% selectivity, via ozone treatment and concurrent UV irradiation and without the generation and release of greenhouse gas (CO2), ozone depleting gas (CH3Br), and wastewater, or the need for a high energy-demand hydropurification process. The reaction mechanism involves the singlet O(1D)- and hydroxyl radical-mediated selective C-H functionalization of p-xylene.
Hwang, Kuo Chu,Sagadevan, Arunachalam,Kundu, Pradip
p. 6082 - 6088
(2019/11/20)

Efficient catalytic oxidation of methyl aromatic hydrocarbon with: N -alkyl pyridinium salts
A series of N-alkyl pyridinium salts were synthesized and employed as metal-free catalyst for the selective oxidation of methyl aromatic hydrocarbon with molecular oxygen. The electronic effect of the substitutes was found to be an important factor for the catalytic performance. With the introduction of electron-donating substitute -N(CH3)2, the conversion of p-xylene and selectivity of p-toluic acid could be simultaneously increased. 1-Benzyl-4-N,N-dimethylaminopyridinium salt showed the highest catalytic activity, and 95% conversion with 84% of selectivity to p-toluic acid could be obtained for the selective oxidation of p-xylene. Several methyl aromatic hydrocarbons could all be efficiently oxidized with the reported catalyst at the absence of any metal species.
Zhang, Qiaohong,He, Honghao,Wang, Huibin,Zhang, Zhan,Chen, Chen
p. 38891 - 38896
(2019/12/11)

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)

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)

Highly active bidentate N-heterocyclic carbene/ruthenium complexes performing dehydrogenative coupling of alcohols and hydroxides in open air
Eight bidentate NHC/Ru complexes, namely [Ru]-1-[Ru]-8, were designed and prepared. In particular, [Ru]-2 displayed extraordinary performance even in open air for the dehydrogenative coupling of alcohols and hydroxides. Notably, an unprecedentedly low catalyst loading of 250 ppm and the highest TON of 32 800 and TOF of 3200 until now were obtained.
Wang, Zhi-Qin,Tang, Xiao-Sheng,Yang, Zhao-Qi,Yu, Bao-Yi,Wang, Hua-Jing,Sang, Wei,Yuan, Ye,Chen, Cheng,Verpoort, Francis
supporting information
p. 8591 - 8594
(2019/07/25)

Cu(II) complexes of N-rich aroylhydrazone: Magnetism and catalytic activity towards microwave-assisted oxidation of xylenes
The new aroylhydrazone N-(di(pyridin-2-yl)methylene)pyrazine-2-carbohydrazide (HL) species, rich in N-donor sites, has been used to synthesize Cu(ii) compounds with different nuclearities, viz. the binuclear [Cu2(μ-1κN3,2κN2O-L)(Cl)3(MeOH)] (1), the octanuclear [Cu4(μ-1κN3,2κN2O-L)2(μ-Cl)3(Cl)3]2 (2) and the 1D coordination polymer [Cu3(μ3-1κN3,2κN2O,3κN-L)(μ-NO3)(NO3)3(H2O)3]n·nNO3 (3). They have been characterized by elemental analysis, FT-IR and single crystal X-ray diffraction. The magnetic properties of 2 and 3 have been explored using variable temperature magnetic measurements. The catalytic performances of the compounds were evaluated towards the peroxidative oxidation of o-, p- A nd m-xylenes under microwave irradiation, leading to the formation of the corresponding methyl benzyl alcohol, tolualdehyde and toluic acid as the major products. Complex 3 exhibits the best catalytic activity towards the oxidation of p-xylene with a total yield of 37% (4-methylbenzyl alcohol + p-tolualdehyde + p-toluic acid).
Sutradhar, Manas,Roy Barman, Tannistha,Alegria, Elisabete C. B. A.,Guedes Da Silva, M. Fátima C.,Liu, Cai-Ming,Kou, Hui-Zhong,Pombeiro, Armando J. L.
p. 12839 - 12849
(2019/09/07)

Surfactant-assisted assembly of nanoscale zinc coordination compounds to enhance tandem conversion reactions in water
Precise control over the morphology and size of coordination polymers (CPs) is crucial for extending these inorganic-organic materials to many advanced applications, in particular for heterogeneous catalysis. In this work, two Zn-based CPs, {[Zn3(idbt)2(4,4′-dmbpy)2]·H2O}n (1) and {[Zn3(idbt)2(H2O)3]·H2O}n (2) (H3idbt = 5,5′-(1H-imidazole-4,5-diyl)-bis-(2H-tetrazole), 4,4′-dmbpy = 4,4′′-dimethyl-2,2′-bipyridine), were synthesized through solvothermal reactions. The morphologies and particle sizes of 1 and 2 could be controlled from large scale to nanoscale by regulating the amount of poly(vinyl alcohol) (PVA). Furthermore, for the conversion reactions of nitromethylbenzenes into benzoic acids, the catalytic properties of nanoscale 1 and 2 were much more efficient than those of large size of 1 and 2, because of the benefit of readily accessible active sites in the nanoscale sized particles, which provide a tunable and functionalizable platform for the conversion reaction by minimizing the diffusion distance but do little for the selectivity.
Huang, Chao,Zhu, Kaifang,Zhang, Yingying,Lu, Guizhen,Shao, Zhichao,Gao, Kuan,Mi, Liwei,Hou, Hongwei
supporting information
p. 16008 - 16016
(2019/11/13)