Search

Porous carbon materials have attracted much attention in the field of organic synthesis in recent years, due to their tunable properties, excellent catalytic activity and stability. Biomass-based carbohydrates emerge as an ideal precursor for the generation of these materials owing to their renewability, low cost, non-toxicity and high content of functional groups. Thus, carbon materials prepared from carbohydrates is of considerable importance for the sustainable development of organic chemistry. The present review not only summarizes recent examples of carbohydrate-derived porous carbon material-catalyzed organic reactions including the oxidation, hydrogenation, cross-coupling, esterification and condensation reactions, but also introduces the preparation and functionalization strategies of these materials. Furthermore, the challenges and opportunities of organic synthesis over these sustainable materials have also been addressed. This review will stimulate further research on exploring novel carbohydrate-derived porous carbon materials and new sustainable organic synthetic processes over these materials.

Organosilicon compounds play an important role in the fields of materials science, pharmacy, and organic synthesis. The development of effective approaches for the preparation of these compounds have also become a research focus in organic synthesis. In recent years, free radical synthesis of organosilicons has been vigorously developed, which generally has the advantages of milder synthesis conditions, higher yields and selectivity, and free of precious metal catalysts compared with traditional strategies. This article reviews research progresses in the synthesis of organosilicon compounds by free radical pathways since 2016. In most cases, the radical silylation is achieved based on the reaction of silyl radicals, which are triggered by four routes including peroxide, transition-metal-induced peroxide decomposition, alkali, photocatalysis. The alkyl radicals can also initiate the radical silylation for the generation of C(sp3) Si bonds.

An efficient, sustainable and scalable strategy for the synthesis of porous cobalt/nitrogen co-doped carbons (Co@NCs) via pyrolysis of aniline-modified ZIFs, has been demonstrated. Aniline can coordinate and absorb on the surface of ZIF (ZIF-CoZn3-PhA), accelerate the precipitation of ZIFs, thus resulting in smaller ZIF particle size. Meanwhile, the aniline on the surface of ZIF-CoZn3-PhA promotes the formation of the protective carbon shell and smaller Co nanoparticles, and increases nitrogen content of the catalyst. Because of these properties of Co@NC-PhA-3, the oxidative esterification of 5-hydroxymethylfurfural can be carried out under ambient conditions. According to our experimental and computational results, a synergistic catalytic effect between CoNx sites and Co nanoparticles has been established, in which both Co nanoparticles and CoNx can activate O2 while Co nanoparticles bind and oxidize HMF. Moreover, the formation and release of active oxygen species in CoNx sites are reinforced by the electronic interaction between Co nanoparticles and CoNx.

Hydrogen auto-transfer (HAT) or borrowing hydrogen (BH) methodology which combines dehydrogenation, intermediate reaction and hydrogenation, is recognized as an excellent strategy for one-pot synthesis from an economic and environmental point of view. Although much effort has been made on the development of catalysts for HAT reactions, harsh conditions, external base or large amounts of noble metals are still required in most reported catalysis systems, and thus the exploration of a highly efficient and recyclable heterogeneous catalyst remains meaningful. In this work, a novel bimetallic catalyst, Fe10Pd1/NC500 derived from bimetallic MOF NH2-MIL-101(Fe10Pd1), has been prepared, and the catalyst exhibits superior catalytic performance for the N-alkylation of amines with alcohols via a hydrogen auto-transfer methodology. High yields of the desired products were achieved at 120 °C with an alcohol/amine molar ratio of 2 : 1 and required no external additive or solvent. A distinct enhancement in catalytic performance is observed when compared with monometallic catalysts, which can be ascribed to the “synergistic effects” inside the bimetallic alloys. The N-doped carbon support has been revealed to provide the necessary basicity which avoids the requirement of an external base. Moreover, a wide substrate range and remarkable reusability have been shown by Fe10Pd1/NC500, and this work highlights new possibilities for bimetallic catalysts applied in sustainable chemistry.

The reaction mechanisms of Rh-catalyzed regioselective hydrothiolation of the allyl amine employing four bidentate phosphine ligands are investigated with DFT calculations. The free energy profiles of anti-Markovnikov and Markovnikov pathways arising from different alkene insertion types are computed to elucidate the ligand-controlled regioselectivity. For 1,2-bis(diphenylphosphino)benzene (dppbz) and 1,3-bis(diphenylphosphino)propane (dppp) ligands with small nature bite angle (βn ≤ 86°), the anti-Markovnikov pathway that features the 1,2-alkene insertion into Rh-H bond is favored by 2 ˜ 4 kcal/mol in barriers of elementary steps. While for 1,4-bis(diphenylphosphino)butane (dppb) and bis(2-diphenylphosphinophenyl)ether (DPEphos) ligands with large nature bite angle (βn ≥ 99°), the Markovnikov pathway with 1,2-alkene insertion into Rh-S bond is preferential by 2 ˜ 7 kcal/mol in barriers. The P-Rh-P bite angle is a reliable predictor and regulator of the regioselectivity of reaction as evidenced by good correlations between reaction barrier and P-Rh-P bite angle. Smaller P-Rh-P bite angle in TSs is generally found for small nature bite angle ligand dppbz and dppp in preferential anti-Markovnikov pathway, while TSs with larger P-Rh-P bite angle are favored by large nature bite angle ligand DPEphos and dppb. Larger difference in P-Rh-P bite angles of TSs between Markovnikov and anti-Markovnikov pathway generally leads to the greater disparity in barrier heights of two pathways, and hence greater regiodivergency of reaction.

A highly efficient bimetallic nanoparticles (BMNPs) catalyst was reported, Pd1Ni4/AC, consisting of Pd1Ni4 BMNPs supported on active carbon, shown excellent catalytic performance and stablity in hydrodeoxygenation (HDO) of vanillin. HDO of vanillin and various aldehydes with high efficiency and selectivity could be achieved at low H2 pressure (2 bar) under mild conditions in the presence of the BMNPs catalyst, no obvious decrease on catalytic performance was observed after eight cycles. The superior catalytic performance of the Pd1Ni4/AC catalyst was mainly attributable to the synergetic electronic effect between Pd and Ni, which showcased the great potential of BMNPs in the catalysis field.

UiO-66(Ce)-encapsulated ruthenium nanoparticles (Ru@UiO-66(Ce)) was designed and used for dehydrogenation of primary amines to nitriles in water without any hydrogen acceptors and additives. Introduction of metal Ru to UiO-66(Ce) contributes to the formation of Lewis acid–base pairs on the catalyst owing to the metal–support interaction, acting as active sites for activation of amines and transfer of hydrogen. Ab initio calculation results further confirm the roles of Lewis acid–base pairs in the reaction.

A newly developed template protection-sacrifice (TPS) strategy is developed for the synthesis of hollow yolk–shell Co@CN with a large surface area and high pore volume. The catalyst exhibits excellent catalytic efficiency in base-free oxidative esterification of 5-hydroxymethylfurfural under mild conditions with excellent selectivity at a high concentration (2 M) of the reactant.

A concerted one-step addition mechanism for anti-Markovnikov hydrothiolation in [Hmim]Br catalyzed thiol–ene reactions is revealed by a combined DFT and experimental study for the first time. This special mechanism represents a typical “ionic liquid effect”, which is driven by the directional hydrogen bond and π+–π interactions that conjoin the substrates and [Hmim]Br into a prereactive complex. The transition state is stabilized and characterized by a planar 6-membered ring containing HBr and four substrate atoms at the reaction site. The concerted addition mechanism and the special structural feature of the TS render the reaction regiospecific, i.e. only the anti-Markovnikov product is produced. When the styrene is replaced by aliphatic alkenes, the substrates are loosely bound with the ionic liquid. As a result, the prereactive complex is destabilized and the reactivity drops significantly.

A newly developed chemoselective reaction of sodium arylsulfinates or arylsulfonyl chlorides with nitroarenes has been disclosed. The chemistry, in which non-toxic water and recyclable iron-based metal-organic frameworks are employed as the solvent and catalyst, respectively, provides an efficient approach for the generation of N-arylsulfonamides, which are widely present in biologically active compounds and drugs, rendering this methodology attractive to both synthetic and medicinal chemistry.

A strategy for the synthesis of coumarin derivatives via visible-light photoredox catalysis has been developed using fac-Ir(ppy)3 as the photocatalyst under mild conditions. Trifluoromethanesulfonyl chloride is utilized as the trifluoromethylation reagent, which is cheap and readily available. Aryl alkynoates are trifluoromethylated, then undergo a radical cyclization and a cascade ester migration to generate target products.

A highly selective anti-Markovnikov hydroboration reaction of alkenes with bis(pinacolato)diboron catalyzed by 4-cyanopyridine has been described. This strategy provides an efficient, practical and environmentally benign protocol for the construction of alkylboronates in moderate to good yields under metal-free conditions. A radical mechanism proceeding via a 4-cyanopyridine-ligated boryl radical was proposed.

The aerobic oxidative coupling of alkynes and phosphite esters can be catalyzed by Cu/Cu2O nanoparticles supported on Nb2O5 (Cu/Cu2O@Nb2O5) to efficiently afford alkynylphosphonates. The catalyst can be reused by filtration and reduction. According to the results of control experiments and characterization data, the supporter Nb2O5 can reduce the electronic density of Cu and absorb the phosphite esters due to its strong Lewis acid sites, which may enhance the reaction efficiently.

An aqueous photocatalytic system was designed by merging visible-light photoredox catalysis with micellar catalysis. Eosin B, an organic dye, was utilized as the photocatalyst, and Triton X-100 was employed as the surfactant; both are inexpensive and commercially available. This clean and energy-saving catalytic system enables photocatalytic reactions of the diazonium ion generated in situ to proceed smoothly in water without any co-solvents or additives at room temperature.

Various indolizines are synthesized through one-pot, two-step 1,3-dipolar cycloadditions in recyclable [Omim]Br with high yields and a broad substrate scope. The promotion of noncovalent interactions between ionic liquids and substrates or intermediates on the reaction is discovered on the basis of the results of control and NMR experiments. Moreover, the 3-arylindolizines can also be prepared from low-activity arylmethylpyridinium ylides in the protocol.

Vesicles self-assembled from an aqueous PEGylated surfactant ionic liquid solution can be applied for stabilizing palladium nanoparticles, which prove to be an efficient catalytic system for chemoselective hydrogen transfer of nitroarenes using hydrazine hydrate as a hydrogen source. The particle sizes of vesicles are decreased with the increase of ionic liquid's concentrations and relatively small particle sizes are beneficial to the reduction. Moreover, the aqueous catalytic system still stays in reactor by simple extraction, and is reused without further treatment.

A one-pot synthesis of β-amino α,α-difluoro ketones is developed without any additives. Through a series of control experiments we found that water plays a crucial and indispensable role. The hydrogen bond between water and fluorinated enol silyl ether has a significant impact on the addition reaction.

Ni5P4 has received considerable attention recently as a potentially viable substitute for Pt as the cathode material for catalytic water splitting. The current investigation focuses on theoretical understandings of the characteristics of active sites toward water splitting using first-principle calculations. The results indicate that the activity of bridge NiNi sites is highly related on the bond number with neighbors. If the total bond number of NiNi is higher than 14, the sites will exhibit excellent HER performance. For the top P sites, the activity is greatly affected by the position of coplanar atoms besides the bond number. Data of bond length with neighbors can be used to predict the activity of P sites as reviewed by machine learning. Partial density of state (PDOS) analysis of different P sites illustrates that the activity of P sites should form the appropriate bond to localize some 3p orbits of the P atoms. Bond number and position of neighbors are two key parameters for the prediction of the HER activity. Based on the current work, most of the low-energy surfaces of Ni5P4 are active, indicating a good potential of this materials for hydrogen evolution reactions. MOE (Min. of Education, S’pore) Published version

Condensation poses a serious challenge to the mechanical durability and sustainable development of modern buildings in tropical environment. Moisture condensation and absorption in architecture causes inconvenience and requires extra maintenance measures. A mechanically durable anti-condensation coating that displays very low affinity with moisture is promising for applications on wall and ceiling of buildings. A main challenge in the fabrication of anti-condensation surface lies with the requirements of preventing water accumulation on the surface while maintaining the breathability of substrate. In this study, a breathable anti-condensation coating has been developed on cementitious substrates based on bio-based epoxy resins. The coating presented water repellency and a condensation delay time of 50 min when compared to the uncoated counterpart at a sub-cooled temperature of 8 °C. The excellent tolerance against condensation was verified after 200 h continuous condensation test according to ISO 6270 standard. The coating also displayed good breathability and moisture resistance, which are key to the inhibition of bacteria growth and structural deterioration in architecture. Moreover, the superhydrophobic sample demonstrated a 9.7% increase in thermal conductivity over the uncoated substrate. Mechanical tests showed good adhesion between the coating and the substrate. The coated area of cementitious substrate maintained its superhydrophobicity even after the bulk coating was removed. The coating also displayed superior mechanical durability over the state-of-the-art anti-condensation coatings. The reported method provides a practically useful and environmentally friendly solution to mitigate water absorption problem of concrete based architectures. Nanyang Technological University Financial support from Surbana Jurong – NTU Corp Lab is greatly acknowledged.

An acid-promoted protocol has been developed to achieve the transition-metal- and phosphorus-free electrophilic trifluoromethylthiolation of indoles using sodium trifluoromethanesulfinates in an imidazolium-based ionic liquid ([Hmim]Br). [Hmim]Br not only acts as a recyclable solvent, but also as the reductant in this transformation. The advantages of this chemistry include simple operation, use of a recyclable solvent, avoidance of transition-metal and phosphorus, and gram-scale synthesis.

A one-pot, catalyst-free route to spiro[dihydroquinoline-naphthofuranone] compounds from isatins through ring-opening and cyclization processes in water is disclosed. Hydrogen-bonding effects of water proved to be the key factor to accelerate the transformation. In addition, the chemistry provides several advantages including that it is free of organic solvents, a simple operation, and a gram-scale synthesis and uses inexpensive reagents and a recyclable reaction medium.

A radical-mediated approach has been introduced for the C-S bond activation of arylalkenyl sulfides. The protocol provides an efficient approach for the generation of various alkenes including alkenyl silanes, sulfones, phosphine oxides, and nitroolefins. In most cases, these radical substitutions are performed under metal-free conditions with stereospecificity.

An efficient, recyclable Pd–Cu bimetallic nanoparticle catalyst has been prepared, which exhibits superior activity and selectivity toward the hydrosilylation of internal and terminal alkynes under mild reaction conditions with a low catalyst loading. Distinct enhancement in catalytic performance is observed when compared with traditional monometallic catalysts, and the composition of BMNPs is found to be crucial in both selectivity and yield. This kind of elevation in catalytic performance can be ascribed to the enrichment of active sites (Pd) on the catalyst surface and a phenomenon collectively referred to as “synergistic effects”. The successful application of BMNPs as catalysts in the alkyne hydrosilylation opens up new possibilities for the excavation of the value of bimetallic nanoparticles in catalysts’ development for sustainable chemistry.

A MIL-100(Fe) supported Pd–Ni BMNP catalyst has been fabricated, and the catalyst exhibits superior catalytic performance toward the intramolecular transfer hydrogenolysis of lignin model compounds and organosolv lignin. Alcoholic groups (CαH-OH) of lignin were exploited as the hydrogen source, and selective cleavage of β-O-4 linkages in lignin was realized without an extra hydrogen donor. This protocol was suitable for organosolv lignin as well as model compounds; several phenols and functionalized acetophenones were detected when extracted lignin was treated in our system. The catalyst exhibits outstanding catalytic stability during the reaction process, which can be ascribed to the porous structure and the strong water stability of MIL-100(Fe). The excellent catalytic performance of Pd1Ni4/MIL-100(Fe) highlights the “synergistic effect” between the BMNPs and the functional synergy between MNPs and MOFs, and our work shows the bright future of BMNPs and MOFs in the development of catalysts for sustainable chemistry.

A practical sliver-catalyzed fluoroalkylation of aryl-, heteroaryl- and alkylthiols has been developed. The reaction has a good functional-group tolerance and excellent selectivity. A variety of stable and solid fluoroalkanesulfinates including di- and perfluoroalkanesulfinates can be employed. This methodology provides a straightforward and streamlined access to perfluoroalkylthiolated organic molecules. Figure options Download full-size image Download high-quality image (173 K) Download as PowerPoint slide

A transition-metal-free direct trifluoromethylthiolation of indole derivatives under mild conditions has been developed. Commercially available sodium trifluoromethanesulfinate (CF3SO2Na) acts as the trifluoromethylthiolating reagent, which is cheap, stable and easy to handle. The substrate scope of this protocol could also be expanded to pyrroles and enamines.

Regioselective arylthiolations of aromatic amines, arenols and ketones via C–H bond functionalization have been achieved with I2 and PPh3 in an aqueous system, whereby arylsulfenyl radicals are in situ generated from odorless sodium arylsulfinates. The arylsulfenyl radicals can react with free anilines containing electron-withdrawing groups and complex substrates (estrone and progesterone). Further experiments and quantum chemical calculations were also performed to deduce a mechanism for the formation of arylsulfenyl radicals.

Highly dispread Ni-Co bimetallic nanoparticles (Ni-Co BMNPs) are synthesized and applied as an efficient catalyst in the chemoselective transfer hydrogenation of nitroarenes (CTH) using hydrazine hydrate as the hydrogen donor. The BMNPs can efficiently catalyze the reduction reaction without any additives under mild conditions with high TOF. Significantly higher activity is achieved when compared with corresponding single-component catalysts, optimal composition of the Ni-Co BMNPs was screened which was proved to be crucial in both the selectivity and yields. Excellent performance of Ni-Co BMNPs can be ascribed to the improved dispersion of active sites on the BMNPs surface (compared with Ni NPs) and the electron transfer from cobalt to nickel.

The nucleophilic aromatic substitution reaction and thia-Michael addition using thiourea as an odorless, cheap, and easy-to-handle sulfur source in water are described, which can be used to teach upper-division undergraduates the role of thiourea in the formation of C–S bonds and the principles of green chemistry. The use of a cheap, nontoxic surfactant Triton X-100 proves to promote both reactions obviously by contrast reactions. The structures of products obtained from the two reactions by students are determined via analyzing nuclear magnetic resonance spectral data. Students also propose the mechanisms of the two reactions and point out the green and nongreen aspects of this experiment.

The fluorine-containing organic compounds are becoming privileged in medicinal chemistry. Described herein is an efficient and environmental friendly method for the synthesis of the gem-difluoromethylene azo compounds without any additives, and the hydrogen bond between water and fluorinated enol silyl ether slightly promote the reaction.

Hf-MOF-808 exhibits excellent activity and specific selectivity on the hydrogenation of carbonyl compounds via a hydrogen transfer strategy. Its superior activity than other Hf-MOFs is attributed to its poor crystallinity, defects and large specific surface area, thereby containing more Lewis acid-base sites which promote this reaction. Density functional theory (DFT) computations are performed to explore the catalytic mechanism. The results indicate that alcohol and ketone fill the defects of Hf-MOF to form a six-membered ring transition state (TS) complex, in which Hf as the center of Lewis stearic acid coordinates with the oxygen of the substrate molecule, thus effectively promoting hydrogen transfer process. Other reactive groups, such as –NO2, C = C, -CN, of inadequate hardness or large steric hindrance are difficult to coordinate with Hf, thus weakening their catalytic effect, which explains the specific selectivity Hf-MOF-808 for reducing the carbonyl group.

The electronic metal-support interactions that are well-known in metal-loaded metal oxides, are also disclosed in Pd@MOFs. According to the experimental and calculation results, the superior catalytic performance of Pd@MIL-125(Ti) is mainly attributed to the higher ratio of Pd0/Pd2+ and electronic density of Pd nanoparticles which are triggered by stronger Lewis base sites and less Lewis acid sites of MIL-125(Ti) respectively. Therefore, the Pd@MIL-125(Ti) catalyzed hydrogenation of nitroarenes and alkenes can be carried out in water using low Pd usage (0.12 mol%) with excellent selectivity under mild conditions (room temperature, 1 atm H2). Moreover, the aqueous catalytic system still stays in reactor by simple extraction, and can be reused without further treatment, thus resulting in low environmental factor.

In this study, we conduct comprehensive experimental and theoretical investigations on the hydrogen evolution reaction (HER) preformation of FeP electrode in acidic and alkaline solutions. Theoretically, bulk Fe-O bond is unfavorable, but surface Fe-O bond is favorable and plays a negative role for HER. The presence of oxygen bonds (native or formed during reaction) is the root source of the reduced HER activity. Surface treatment in 37% HCl solution removes the oxide layer and significantly improves the HER performance, especially in alkaline solution. After etching, the overpotentials in 0.5 M H2SO4 are 79 and 95 mV at 10 and 20 mA cm−2, respectively. The ones in 1 M KOH are 95 and 102 mV at 10 and 20 mA cm−2, respectively. Long-term instability in alkaline solution is caused by the presence of oxygen in the electrolyte. Good stability can be realized by removing oxygen from the solution. Ministry of Education (MOE) National Research Foundation (NRF) Accepted version Financial support from following is gratefully acknowledged: Ministry of Education - Singapore (RG15/16, RG16/18), National Research Foundation, Singapore (SINBERISE), National Natural Science Foundation of China (No. 21676216).

Cellulose with tailorable hydrophilicity/hydrophobicity were synthesized by grafting F-containing groups and utilized as supports for palladium nanoparticles. The obtained catalysts were applied in the synthesis of N-phenylhydroxylamine from controllable reduction of nitrobenzene. Unexpectedly high conversion and selectivity could be achieved with 25 ppm Pd catalyst at room temperature in water. The precise modification of the catalyst surface is crucial to realize this targeted transformation. Further investigation indicated that modified cellulose with a more hydrophobic surface would favour the adsorption of nitrobenzene over N-phenylhydroxylamine thus prevent full hydrogenation to aniline.

An efficient sulfonylation of activated alkenes with sodium arylsulfinates in water at room temperature is introduced. Water proves to enhance more obviously the transformation compared with other solvents. The quantum chemical calculations suggest that the protonation of alkenes is the key step of the reaction, which could be accelerated by polarity effects of water. Moreover, water can polarize and stabilize the charged intermediates based on the results of quantum calculations.

The β-O-4 linkage in lignin can be selectively cleaved by Pd–Ni bimetallic nanoparticles supported on ZrO2 using hydrogen gas as the hydrogen donor under ambient pressure and neutral conditions. Conspicuous enhancement in activity is observed compared with single nickel and palladium catalysts based on the results of experiments and characterization. Moreover, hydrogenation of the produced phenols is tuned by adjusting the amount of NaBH4. The catalyst can be reused over ten times in the model reaction and over five times in the hydrogenolysis of lignin without an obvious change in activity and selectivity.

A mild, simple and metal-free radical [4 + 2] benzannulation for the generation of phenanthrenes has been developed. A substoichiometric reductant, ascorbic acid (vitamin C), is harnessed as the radical initiator. This method has a broad substrate scope, and various substituted phenanthrenes were obtained in moderate to good yields at room temperature without irradiation.

A facile aromatic nucleophilic substitution (SNAr) reaction in recyclable [Omim]Br under relatively mild conditions has been described. An electrophile–nucleophile dual activation by [Omim]Br is also discovered based on control experiments, 1H NMR and IR spectroscopies. This chemistry provides an efficient and metal-free approach for the generation of Caryl–X (XS, N, O) bonds, many of which are significant synthetic intermediates or drugs, making this methodology attractive to both synthetic and medicinal chemistry.

A method for photocatalytic oxidative coupling of diaryl phosphine oxide and arylacetylene under mild conditions was developed. Rhodamine B, an inexpensive and commercially available organic dye, was used as the photocatalyst. This protocol realizes a regioselective 1,2-difunctionalization of arylacetylenes and provides a metal-free access toward a series of β-ketophosphine oxides.

An efficient and highly regioselective protocol for copper(II)-catalyzed remote C–H fluoroalkylation of 8-aminoquinoline amides with RfSO2Na (Rf = CF3, CF2H, C4F9, C5F11, and C6F13) is described. This reaction provides an effective strategy for the direct construction of fluorine-containing six-membered heteroaromatic core structures.

A selective and facile trifluoromethylation process for a wide range of thiophenols and thiols under metal free conditions has been developed using two simple and safe solids, sodium trifluoro-methanesulfinate and iodine pentoxide, via the radical process.

Effective hydrodeoxygenation (HDO) of dibenzofuran (DBF) catalyzed by a bimetallic nickel/platinum (Ni/Pt) catalyst in water was demonstrated at 200 °C and 1.2 MPa hydrogen (H2) pressure. The bimetallic catalysts prepared by a wet chemical method exhibit prominent activity that overcomes the limitations of use of a single Ni or Pt metal catalyst. The yield of HDO products can be up to 90%. Reaction results indicate that the conversion of DBF was affected by the reaction temperature and H2 pressure. The deoxygenation selectivity was strongly dependent on reaction temperature. The reaction pathway is also proposed.

A new protocol for achieving the phosphination of arenes, arenols and thiols has been disclosed. This chemistry, in which diaryl(((trifluoromethyl)sulfonyl)oxy)phosphines as a kind of electrophilic phosphination reagents are in situ generated from diarylphosphine oxides, provides an efficient and mild approach for the synthesis of aromatic organophosphorus compounds.

A mild and efficient method for the photocatalytic radical cyclization of α-halo hydrazones with β-ketocarbonyls has been described. This strategy provides a potential protocol for the construction of functionalized 4,5-dihydropyrazoles in moderate to high yields.

An acid-induced protocol for the chemoselective arylthiolations of electron-rich arenes in ionic liquids from sodium arylsulfinates is introduced. The chemistry, in which [Hmim]Br (heaxylmethylimidazolium bromide) is used as both a solvent and a reducer, provides several advantages including odorless and simple operation, inexpensive reagents, recyclable solvents and gram-scale synthesis.

A newly developed, facile and sustainable self-sacrifice template strategy, in which zinc and chitosan were used as the sacrificial template and carbon source respectively, has been disclosed for the synthesis of a hollow Co-embedded in nitrogen-doped graphite (Co@CN) structure. This material exhibits excellent catalytic efficiency in the oxidative esterification of 5-hydroxymethylfurfural to 2,5-furandicarboxylicacid dimethyl ester that is a significant raw material for polymer synthesis. According to the experimental and calculation results, zinc as the self-sacrificial template and acid-base site regulator has significantly improved the performance of the catalyst. The high specific surface area owing to the partial evaporation of zinc and the optimization of basic and acid sites in the catalyst prove to be the main reasons for its high activity.

Fluorine-containing organic compounds are gaining increasing importance in medicinal chemistry. Described herein is a mild and efficient method for the radical addition of olefins with TMSCF3 and TMSCF2R (R = COOEt or CF3) to deliver various α-trifluoromethylated ketones and α-fluoroolefinated ketones.

Transition-metal-free radical access to 1,4-benzothiazine derivatives from o-aminobenzenethiols is disclosed. This procedure is available for various ketones including α,β-unsaturated, cyclic, linear, and fluoroalkyl ketones to generate a number of 1,4-benzothiazines, which exist in numerous bioactive and natural molecules, rendering this protocol attractive to both synthetic and medicinal chemistry.