Efficient light-driven reductive amination of furfural to furfurylamine over ruthenium-cluster catalyst

Selective reductive amination of carbonyl compounds with high activity is very essential for the chemical and pharmaceutical industry,but scarcely successful paradigm was reported via efficient photocatalytic reactions.Herein,the ultrasmall Ru nanoclusters(~0.9 nm)were successfully fabricated over P25 support with positive charged Ru^(δ+)species at the interface.A new route was developed to achieve the furfural(FAL)to furfurylamine(FAM)by coupling the light-driven reductive amination and hydrogen transfer of ethanol over this type catalyst.Strikingly,the photocatalytic activity and selectivity are strongly dependent on the particle size and electronic structure of Ruthenium.The Ru^(δ+)species at the interface promote the formation of active imine intermediates;moreover,the Ru nanoclusters facilitate the separation efficiency of electrons and holes as well as accelerate the further hydrogenation of imine intermediates to product primary amines.In contrast Ru particles in larger nanometer size facilitate the formation of the furfuryl alcohol and excessive hydrogenation products.In addition,the coupling byproducts can be effectively inhibited via the construction of sub-nanocluster.This study offers a new path to produce the primary amines from biomass-derived carbonyl compounds over hybrid semiconductor/metal-clusters photocatalyst via light-driven tandem catalytic process.

One-step Eco-friendly Fabrication of Antibacterial Polyester Via On-line Amination Reaction by Melt Coextrusion

The work is dedicated to develop a one-step eco-friendly method to prepare antibacterial polyethylene terephthalate(PET).We report a one-step eco-friendly method to manufacture antibacterial PET via on-line amination reaction by melt coextrusion.Beside evenly mixing of poly(hexamethylene guanidine)(PHMG)and PET in the melt coextrusion procedure,the amination reaction also occurred between PHMG and PET under high temperature(230-270℃).The antibacterial ability of composite PET showed obvious PHMG concentration dependence,and antibacterial activity reached more than 99%when PHMG content was 2.5 wt%.Moreover,LIVE/DEAD fluorescence test further confirmed that the composite PET could kill bacteria quickly and efiectively(within 30 min);while negligible cytotoxicity was observed to HSF and HUVEC cells.Onestep eco-friendly fabrication of composite antibacterial PET was accomplished by on-line melt coextrusion.The composite antibacterial PET has potential use in multiple fields to combat with pathogenic including textiles,packaging materials,decoration materials and biomedical devices,etc.

Selectively reductive amination of levulinic acid with aryl amines to N-substituted aryl pyrroles

Synthesizing nitrogen(N)-containing molecules from biomass derivatives is a new strategy for production of this kind of chemicals.Herein,for the first time we present the synthesis of N-substituted aryl pyrroles via reductive amination/cyclization of levulinic acid(LA)with primary aromatic amines and hydrosilanes(e.g.,PMHS)over Cs F,and a series of N-substituted aryl pyrroles could be obtained in good to excellent yields at 120○C.The mechanism investigation indicates that the reaction proceeds in two steps:the cyclization between amine and LA occurs first to form intermediate 5-methyl-N-alkyl-1,3-dihydro-2H-pyrrolones and their isomeride(B),and then the chemo-and region-selective reduction of intermediates take place to produce the final products.This approach for synthesis of N-substituted aryl pyrroles can be performed under mild and green conditions,which may have promising applications.

Direct amination of benzene to aniline with several typical vanadium complexes

The liquid-phase direct catalytic amination of benzene to aniline was performed in acetic acid water solvent using a series of vanadium （Ⅲ, Ⅳ,Ⅴ） complexes with N,O- or O,O-ligands as catalysts and hydroxylamine hydrochloride as the aminating agent. The vanadium complexes exhibited much higher selectivity towards the production of aniline than NaVO3 or VOSO4. Under the optimized conditions, an aniline yield of 42.5% and a TON of 48 with a high selectivity of above 99.9% was obtained using 0.2 mmol of [VO（OAc）2] as the catalyst.

Partial amination of cationic exchange resins and its application in the hydration of butene

In this work, the amination of sulfonated polystyrene resin with alkyl secondary amine is investigated. The catalytic activities of the modified resins are determined through the hydration of l-butene. The optimum chain length and the best range of amination rate are determined. It is found that the single-pass conversion of 1 -butene was raised 2% on average, and the relative activity was increased over 30% after modification. A hypothesis about the enhancement of catalytic activities by the inclusion of alkyl chain to wrap up the butene molecule is proposed.

Preparation of 2,5-Bis(Aminomethyl)Furan by Direct Reductive Amination of 2,5-Diformylfuran over Nickel-Raney Catalysts

The direct reductive amination of 2,5-diformylfuran (DFF) with ammonia to 2,5-bis(aminomethyl)furan (BAF) was demonstrated, for the first time, over the commercial type Nickel-Raney and acid treated Nickel-Raney catalysts. The effects of reaction parameters such as reaction medium, temperature and hydrogen pressure were described. The acid treated Nickel-Raney catalyst exhibited the highest BAF yield in the THF-water mixed reaction medium. The relatively higher Ni0 species composition and larger surface area of the acid treated Nickel-Raney catalyst with specific reaction conditions contributed greatly to the BAF formation. The oligomeric species, such as furanic imine trimers and tetramers confirmed by MALDI-MS analysis were presented as the intermediates of DFF reductive amination.

ZrCl_4/Hantzsch 1,4-dihydropyridine as a new and efficient reagent combination for the direct reductive amination of aldehydes and ketones with weakly basic amines

ZrCl4/Hantzsch 1,4-dihydropyridine is a mild and highly efficient reagent combination for the direct reductive amination. Weakly basic amines such as anilines substituted by electron-withdrawing group and heteroaromatic amines can be reductively alkylated with electron rich aldehydes and ketones under mild conditions to form the secondary amines in excellent yields.

Direct amination of isobutylene over zeolite catalysts with various topologies and acidities

The atomically economic and green chemical reaction of direct amination of isobutylene to tertbutylamine, particularly under the relative mild reaction conditions available for future industrial use,was carried out over zeolite catalysts possessing different topological structures, from one dimensional to three dimensional pore system, and from small 8-member ring pore（MRP） to medium 10 MRP and further to large 12 MRP zeolites, to disclose the relationship between the zeolite properties/topologies and their amination performance systematically under the mild reaction conditions. It was discovered that the pore structure and the acidities of zeolite catalysts played crucial roles in the isobutylene amination process, and suitable pore diameter（larger than 0.5 nm or with large side pockets/cups in the outside surface） and a certain number of mid-strong acid sites are indispensable to catalyze the amination reaction,while too strong acid strength was not conducive to the process of isobutylene amination. Among them,zeolites with topologies of BEA, MFI, MEL, MWW and EUO exhibited good amination performance, with which the isobutylene conversion was higher than 12.61%（>46.42% of the equilibrium conversion） under the studied mild reaction conditions. Due to the good amination performance and the large adjustable Si/Al;ratio range, ZSM-5 was selected to further study the effect of acidity on the amination performance systematically under the mild reaction conditions, and the activity-acidity relationship in the amination process was disclosed: the amination activity（isobutylene conversion） had a linear correlation with the amount of mid-strong B acidity under the studied conditions over ZSM-5 catalyst, which can provide guidance for further developing high-efficient amination catalyst under mild reaction conditions available for future industrial use.

Amination of biochar surface from watermelon peel for toxic chromium removal enhancement

Watermelon peel residues were used to produce a new biochar by dehydration method.The new biochar has undergone two methods of chemical modification and the effect of this chemical modification on its ability to adsorb Cr(VI)ions from aqueous solution has been investigated.Three biochars,Melon-B,Melon-BO-NH_(2) and Melon-BO-TETA,were made from watermelon peel via dehydration with 50%sulfuric acid to give Melon-B followed by oxidation with ozone and amination using ammonium hydroxide to give Melon-BO-NH_(2) or Triethylenetetramine(TETA)to give Melon-BO-TETA.The prepared biochars were characterized by BET,BJH,SEM,FT-IR,TGA,DSC and EDAX analyses.The highest removal percentage of Cr(VI)ions was 69%for Melon-B,98%for Melon-BO-NH_(2) and 99%for Melon-BO-TETA biochars of 100 mg·L^(−1) Cr(VI)ions initial concentration and 1.0 g·L^(−1) adsorbents dose.The unmodified biochar(Melon-B)and modified biochars(Melon-BO-NH_(2) and Melon-BO-TETA)had maximum adsorption capacities(Q_(m))of 72.46,123.46,and 333.33 mg·g^(−1),respectively.The amination of biochar reduced the pore size of modified biochar,whereas the surface area was enhanced.The obtained data of isotherm models were tested using different error function equations.The Freundlich,Tempkin and Langmuir isotherm models were best fitted to the experimental data of Melon-B,Melon-BO-NH_(2) and Melon-BO-TETA,respectively.The adsorption rate was primarily controlled by pseudo-second–order rate model.Conclusively,the functional groups interactions are important for adsorption mechanisms and expected to control the adsorption process.The adsorption for the Melon-B,Melon-BO-NH_(2) and Melon-BO-TETA could be explained for acid–base interaction and hydrogen bonding interaction.

Reductive amination of aldehydes and ketones using sodium borohydride in the presence of silica chloride under solvent-free conditions

A simple and convenient procedure for the preparation of amines from aldehydes and ketones with sodium borohydride activated by silica chloride as a catalyst under solvent-free conditions is described.A variety of aliphatic and aromatic aldehydes,ketones and amines when mixed with NaBH;/silica chloride at room temperature,afforded excellent yield of the corresponding amines.

THE DETAILED ARTICLES OF THE PLAN FOR THE PROFICIENCY EXAMINATION FOR INTERNATIONAL ACUPUNCTURE & MOXIBUSTION PROFESSIONALS(FOR TRIAL IMPLEMENTATION)

1.In order to explain the relevant itemsof the Plan for the Proficiency Examinationfor International Acupuncture andMoxibustion (A & M) Professionals (forTrial Implementation),these detailed arti-cles are laid down.2.The additional test subject in the ex-amination is only for those candidates des-cribed in 5.1.3 and 5.1.4 of the Plan for

THE PLAN FOR THE PROFICIENCY EXAMINATION FOR INTERNATIONAL ACUPUNCTURE AND MOXIBUSTION PROFESSIONALS(FOR TRIAL IMPLEMENTATION)

1.Purposes of the Examination1.1 To make the education and exami-nation system of Acupuncture andMoxibustion(A & M)gradually be formaland standard,so as to improve the profes-sional quality of international A & M profes-sionals with continuous efforts.

Study on RE-Modiffied Mordenite Catalysts for Amination Reaction

The effects of RE modified mordenite catalysts on the activity and selectivity of amination reaction at atmospheric pressure in a fixed bed reactor were studied. The experimental result shows that the Y modified mordenite catalyst exhibits very good activity and selectivity to dimethylamine(DMA). The results of the catalyst characterization demonstrate that the rare earth modification of mordenite mainly causes the changes of B acidic sites in mordenite. The crystal structure and the Si/Al ratio on the surface of mordenite basically remain unchanged after mordenite is modified by rare earth elements. Rare earth modification improves the thermal stability and prolongs the life of the catalyst.

Direct and Indirect Electro-Oxidative Intramolecular C–H Aminations

The ubiquity of N-heterocycles in marketed drugs makes the development of metal-free methodologies for constructing C–N bonds of considerable importance.As an environmentally friendly method,electro-oxidative intramolecular C–H amination has emerged as a powerful platform for synthesizing nitrogen-containing heterocycles under metal-and external oxidant-free conditions.In this minireview,the main achievements in this direction since 2020 are summarized,with an emphasis on the substrate scope and mechanistic aspects.The reactions are classifi ed into two categories:direct and indirect electro-oxidative intramolecular C–H aminations.

AMINATION OF ETHANOL WITH AMM0NIA OVER H βZEOLITE

Ethylamine is sc feetively produced in the aminationof ethanol with ammonia over H β zeolite.

Asymmetric Reductive Amination of Carbonyl Compounds by Using<i>N,N,N</i>-Tributylpropanaminium Based Novel Chiral Ionic Liquid

Asymmetric reductive amination of carbonyl compounds was carried out using a novel class of aliphatic quarternary ammonium based chiral ionic liquid. S-(+)-2,3-dihydroxy-N,N,N-tributylpropanaminum bromide chiral ionic liquid has been synthesized, characterized and used for asymmetric reductive amination of carbonyl compounds in the presence of sodium borohydride. These preliminary results are encouraging and advocate dual role of novel ionic liquid as a medium and reducing agent for proficient conversion of ketones to amines, however, reductive amination reaction needs to be established for other substituents.

Reductive Amination with [¹¹C]Formaldehyde: A Versatile Approach to Radiomethylation of Amines

Carbon-11 radiolabeled amines constitute a very important class of radioligands that are widely used for positron emission tomography (PET) imaging. Radiolabeling of amines is often achieved through radiomethylation using [11C]CH3I or [11C]CH3OTf under basic conditions in a strictly anhydrous environment. Functional groups such as hydroxyl and carboxyl groups that are often present in the molecules are normally base sensitive and require protection and deprotection, which substantially prolongs and complicates the radiolabeling process. Here we report a versatile approach to a series of C-11 radiolabeled amines prepared through reductive amination using [11C]formaldehyde. Using a variety of substrates bearing different functional groups, we demonstrate the general utility of this method. In contrast to conventional radiomethylation methods, the reductive amination using [11C]formaldehyde can be carried out in an aqueous environment relatively quickly without the need of protection of base-sensitive functional groups.

Protecting-group-free amination of halogenated nitrobenzaldehyde with palladium catalyst

"One-step"method for the synthesis of secondary aliphatic amine substituted nitrobenzaldehyde was developed.In the presence of Pd catalyst,halogenated nitrobenzaldehyde could be smoothly coupled with secondary aliphatic amine to give the target product in hexamethylphosphamide(HMPT) media without the protection of aldehyde groups.

Decarboxylative Amination with Nitroarenes via Synergistic Catalysis

In this paper,we have developed a decarboxylative amination of carboxylic acids with nitroarenes for the synthesis of secondary amines.The protocol is performed at mild conditions without the use of noble metals as catalysts.A wide range of structurally diverse secondary amines could be obtained in good yields(up to 94%)with good functional group tolerance.This transformation shows good to excellent selectivity,avoiding the generation of over alkylated byproducts.

A Highly Efficient Ni/Al_(2)O_(3)-LaO_(x) Catalyst for the Reductive Amination of Furfural to Furfurylamine:the Promoting Effect of La

The reductive amination of furfural to furfurylamine is an important and still challenging topic in the field of biomass conversion. In this work, we prepared a series of Ni/Al_(2)O_(3)-LaO_(x) catalysts by co-precipitation method, the role of La played in promoting the catalytic performances of reductive amination furfural was discussed based on the changes in the electronic state of Ni species, acidity, and Ni particle size. The catalytic activity and the selectivity of furfurylamine are highly dependent on the surface properties and the structure of the catalyst. The addition of La promoted the amount of strong acidic sites and the H2dissociation and spillover on the surface, thus inducing the improvement of the catalytic activity and furfurylamine selectivity. The Ni/Al_(2)O_(3)-0.5LaO_(x)catalyst with suitable acid sites gave a high yield of furfurylamine (94.9%) under mild reaction conditions. Moreover, the catalyst could be recycled five times without significant loss in activity. The Ni/Al_(2)O_(3)-LaO_(x) catalyst is of great promise in the production of amines via reductive amination reaction.