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In Wacker oxidation and inspired Pd(ii)/Cu(ii)-catalyzed C–H activations, copper(ii) is believed to serve in re-oxidizing of Pd(0) in the catalytic cycle. Herein we report that non-redox metal ions like Sc(iii) can promote Wacker-type oxidations even better than Cu(ii); both Sc(iii) and Cu(ii) can greatly promote Pd(ii)-catalyzed olefin isomerization in which the redox properties of Cu(ii) are not essential, indicating that the Lewis acid properties of Cu(ii) can play a significant role in Pd(ii)-catalyzed C–H activations in addition to its redox properties. Characterization of catalysts using UV-Vis and NMR indicated that adding Sc(OTf)3 to the acetonitrile solution of Pd(OAc)2 generates a new Pd(ii)/Sc(iii) bimetallic complex having a diacetate bridge which serves as the key active species for Wacker-type oxidation and olefin isomerization. Linkage of trivalent Sc(iii) to the Pd(ii) species makes it more electron-deficient, thus facilitating the coordination of olefin to the Pd(ii) cation. Due to the improved electron transfer from olefin to the Pd(ii) cation, it benefits the nucleophilic attack of water on the olefinic double bond, leading to efficient olefin oxidation. The presence of excess Sc(iii) prevents the palladium(0) black formation, which has been rationalized by the formation of the Sc(iii)…H–Pd(ii) intermediate. This intermediate inhibits the reductive elimination of the H–Pd(ii) bond, and facilitates the oxygen insertion to form the HOO–Pd(ii) intermediate, and thus avoids the formation of the inactive palladium(0) black. The Lewis acid promoted Wacker-type oxidation and olefin isomerization demonstrated here may open up a new opportunity in catalyst design for versatile C–H activations. [ABSTRACT FROM AUTHOR]

Al in: A new strategy was introduced to modify the electronics and steric hindrance of the PdII ion in order to change its reactivity towards benzene hydroxylation. In trifluoroacetic acid, free PdII ions provide dominantly biphenyl, with phenol as minor product. Ligation of bpym to the PdII ion results in its deactivation with regard to benzene functionalization. The addition of the redox inactive AlIII ion to the PdII(bpym) complex recovers its catalytic activity, and alters the reactivity of PdII ion from benzene coupling to hydroxylation. [ABSTRACT FROM AUTHOR]

Multiple transition metal functional groups including metaloxo, hydroxo, and hydroperoxide groups play significant roles in various biological and chemical oxidations such as electron transfer, oxygen transfer, and hydrogen abstraction. Further studies that clarify their oxidative relationships and the relationship between their reactivity and their physicochemical properties will expand our ability to predict the reactivity of the intermediate in different oxidative events. As a result researchers will be able to provide rational explanations of poorly understood oxidative phenomena and design selective oxidation catalysts. This Account summarizes results from recent studies of oxidative relationships among manganese(IV) molecules that include pairs of hydroxo/oxo ligands. [ABSTRACT FROM AUTHOR]

Two ultra rigid, o-xylylene cross-bridged macrobicyclic ligands, 1,10,13,19-tetraazatricyclo[8.6.6.03,8]docosa-3,5,7-triene (H2XBC), and 13,19-dimethyl-1,10,13,19-tetraazatricyclo[8.6.6.03,8]docosa-3,5,7-triene (Me2XBC), have been synthesized and the manganese complexes have been synthesized and characterized, including an X-ray structure determination. Mn(Me2XBC)Cl2 displays a relatively high redox potential for the Mn2+/Mn3+ couple (+0.947V vs SHE, measured in CH3CN), suggesting that the manganese(III) complex may be capable of hydrogen abstraction from moderately active substrates. Direct reaction of the freshly synthesized manganese(III) complex, [Mn(Me2XBC)Cl2]PF6, with 1,4-cyclohexadiene confirmed its hydrogen abstracting ability. The manganese(II)/Me2XBC complex is activated by dioxygen in buffered basic aqueous solutions and catalyzes hydrogen abstraction from selected substrates. A possible mechanism for this manganese complex catalyzed dioxygen activation and hydrogen abstraction is proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • O 2 −, 1O 2 and SO 4 − were the dominant ROS species in NZVI@OATP/PDS system. • The conceivable mechanism of PHE and DBP degradation was proposed by DFT calculations and LC–MS analysis. • Ecotoxicities of PHE and DBP and its degradation intermediates were analyzed by TEST method. • NZVI@OATP could maintain 50 % PHE degradation within 30 min after five cycle. Endocrine-disrupting pollutants have become a major problem in aquatic environments. Advanced oxidation processes are recognized as promising technologies for treating endocrine disruptor-contaminated water. Herein, a novel nanoscale zero-valent iron loaded organo-attapulgite (NZVI@OATP) was employed as a catalyst to activate persulfate (PDS) for phenanthrene (PHE) and dibutyl phthalate (DBP) degradation. NZVI@OATP with a NZVI:OATP mole ratio of 1:1 (CTAB:ATP = 1:200) exhibited 100 % PHE and 84 % DBP degradation within 30 min, and chloride was found to have a positive effect on their degradation. Radical scavenger and electron paramagnetic resonance studies revealed that the contribution of the active species follows the order of O 2 - ≈ 1 O 2 > SO 4 - ≫ OH. The optimal degradation pathways were proposed based on the liquid chromatography-mass spectrometry and density functional theory and the possible degradation paths of PHE and DBP, including the 9,10-phenanthraquinone and phthalic acid pathways, respectively, were proposed. The toxicity estimation software tool showed that the toxicities of PHE and DBP were reduced after degradation. Moreover, 50 % PHE degradation could be achieved after five cycles, demonstrating that NZVI@OATP is a promising catalyst for endocrine disruptor treatment with PDS. [ABSTRACT FROM AUTHOR]

The cross‐bridged cyclam manganese complex Mn(Me2EBC)Cl2 efficiently catalyzes the oxidation of benzylic and aliphatic alcohols at pH 3 in a mixture of acetonitrile and water at room temperature. The environmentally benign and high oxygen content oxidant H2O2 was adopted. Conversions of the alcohols to the corresponding carbonyl compounds reached 98 % with good to excellent selectivity. In addition, several lignin model compounds were also catalytically oxidized under these conditions, with excellent conversion (up to 96 %) and selectivity (up to 99 %). The oxidation of benzylic and aliphatic alcohols is efficiently catalyzed by cross‐bridged cyclam manganese complex Mn(Me2EBC)Cl2 at pH 3 in a mixture of acetonitrile and water at room temperature. H2O2 was used as oxidant. In addition, several lignin model compounds were also catalytically oxidized under these conditions, with excellent conversion (up to 96 %) and selectivity (up to 99 %). [ABSTRACT FROM AUTHOR]

Transition‐metal‐catalyzed oxidative C−H amination reactions are among the most attractive topics in organic synthesis to construct nitrogen‐containing motifs. The challenge is that most of these reactions employed stoichiometric oxidants to achieve satisfied catalytic efficiencies. Herein, we report a Pd(II)/LA‐catalyzed (LA: Lewis acid) oxidative C−H amination reaction of 2‐acetaminobiphenyls to construct carbazoles by using dioxygen balloon as the sole oxidant source, and the presence of LA sharply improved the catalytic efficiency of Pd(OAc)2. Remarkably, in certain cases, the deacetylation of the annulation product happened under standard conditions to afford free carbazoles as the final product. The H/D exchange studies confirmed the reversibility of C−H activation and also disclosed multiple C−H activation sites by using −NAc and −NTs as the directing groups. In addition, the palladacycle compound was identified through 1H NMR characterizations and proved to be the intermediate prior to the carbazole formation. [ABSTRACT FROM AUTHOR]

Herein, we present the first systematic investigation to clarify the effect of hydrological rhythms on the concentrations and distributions of polycyclic aromatic hydrocarbons (PAHs) and phthalate esters (PAEs) in the Danjiangkou Reservoir. The results revealed that hydrological rhythms remarkably affected the PAH and PAE concentrations and distributions in the water body, wherein the PAH concentration peaked in the flood season while the PAE concentration remarkably increased in the dry season. This study represents methodological innovation, revealing significant heterogeneity of PAHs and PAEs across different water layers. The former compounds tended to accumulate in the water body's bottom layer while the latter compounds had the highest concentration at the surface layer, which can be attributed to the different physicochemical properties and environmental transport behaviors of the two compound types. The overall concentrations of PAHs and PAEs fall within the international and domestic safety standards. The primary sources of these contaminants—coal and biomass combustion for PAHs and widespread use of plastic products for PAEs—are critical areas of regulatory focus. A machine learning model is proposed for the first time for predicting PAE concentrations in the Danjiangkou Reservoir, primarily based on the stacking model and supplemented by the random forest or XGBoost models. [Display omitted] • Hydrological rhythms markedly affect PAH–PAE concentrations and distributions. • PAHs and PAEs, in order, mainly result from coal–biomass combustion and plastics. • Eco-factors notably impact PAH–PAE characteristics, varying across three water periods. • Stacking model effectively simulates PAE concentration changes in Danjiangkou Reservoir. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) pose versatile risks to the environment and human health. However, studies on their occurrences, spatial distributions, seasonal variations, possible sources and potential risks of the Han River are still not clear. In this study, 16 PAHs were investigated in the surface water and sediments from 15 sampling sites of the Middle and Lower Reaches of the Han River during the dry, normal, and flood seasons. It was found that the sum concentration of PAHs (ΣPAHs) determined by GC-MS ranged from 18.3 to 146.8 ng/L (mean 77.4 ng/L) in surface water, while it was 137.1–1478.4 ng/g (mean 679.6 ng/g) in sediments. The two to three rings PAHs in surfer water and four-five-ring in sediments PAHs comprised the majority of the detected compounds. The level of PAHs in dry season was higher than that in the flood and normal seasons, and the distributions of PAHs varied substantially along the river without clear trend in surface water and sediments. The sources of PAHs in surface water and sediments were mainly from biomass and coal combustion, followed by petroleum combustion. The human health risk of PAHs were evaluated using the risk entropy method of Kalf in surface water, and the mean effects range-median quotient method in sediments, respectively. Overall, the potential health risks caused by PAHs are still acceptable with special concerns about certain specific issues. [Display omitted] • Anthracene in surface water and benzo[ a ]anthracene in sediment are the most predominant PAHs. • The sum concentration of PAHs show the highest concentration in dry season. • The main sources of PAHs are biomass and coal combustion. • Potential health risks of PAHs are acceptable with concerns. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synergetic effect of Lewis acid and Ru(II) catalyst was demonstrated in catalytic isomerization. • Z-isomers were found as the dominant product. • The catalytic activity improvement is Lewis acidity strength dependent. • Five-membered Ru complex from anchimeric assistance from substrate and Lewis acid was recognized as the key intermediate. In catalytic double bond migration reaction, E -configuration olefins were normally generated as the dominant product because E -configuration was thermodynamically favored. However, Z-configuration products are sometimes desired in pharmaceutical chemistry owing to the structure-activity relationship. In this paper, we have demonstrated a new strategy that Lewis acid promoted an widely employed and convenient ruthenium(II) complex for the catalytic isomerization of O-allylethers, leading to thermodynamic-unfavored Z-product under mild conditions. The model substrate of allyl phenyl ether can be simply scaled up to 20 mmol to produce Z-product with TON of 2453 and TOF of 13,430 h−1 at 40–60 °C. The system of Ru(II)/Lewis Acid catalysts was suitable for various substituted O -allylethers and other types of substrates. Through mechanism study including kinetic study, ligand inhibition effect and molecular spectroscopy, the dissociation of PPh 3 ligand by the addition of Lewis acid, and the formation a five-membered Ru complex from anchimeric assistance were both recognized as essential steps to improve the reactivity and to control the stereoselectivity of catalytic double bond migration reaction through metal hydride addition-elimination mechanism. This new strategy may provide a new opportunity to produce thermodynamic-unfavored product in heterocyclic compounds for pharmaceutical chemistry. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bifunctionalized FFA was synthesized from furfural derived 5-bromofurfural. • The carbonylation was conducted in oil/aqueous bi-phase with high yield. • The FFA product can be feasibly separated from catalyst and substrate. Utilizing sustainable biomass to partly replace the fossil feedstock as the carbon source of chemical industry has been well acknowledged because of the scarcity of the fossil resources. This work introduced a novel route for the synthesis of 5-formyl-2-furancarboxylic acid (FFA) from renewable furfural derived 5-bromofurfural, which achieves the transformation of furfural based platform molecule to the products having multifunctional groups, thus opens up its potential market in polymeric applications. Under the optimized conditions, this new catalysis provided up to 99% yield of FFA through oil/aqueous bi-phasic carbonylation. Remarkably, the FFA product could be feasibly separated from the remaining substrate and catalyst because of its aqueous solubility in the biphasic system, giving 95% isolated yield in gram scale synthesis. Currently, FFA is an unstable intermediate in hydroxymethylfurfural (HMF) oxidations; in viewing of that furfural is industrially produced from bulky agroforestrial byproducts, this furfural based route to FFA through catalytic carbonylation has offered an opportunity for its production in large scale. [ABSTRACT FROM AUTHOR]

[Display omitted] • FDCA was obtained from 5-bromofuroic acid with >99% yield. • The catalytic route provides an alternative to the route starting from HMF. • It provides a promising market for furfural and CO utilizations. 2,5-Furandicarboxylic acid (FDCA) is regarded as a biomass based alternative to p-phthalic acid in polymer industry. Although it can be produced through catalytic oxidation of hydroxylmethyl furfural (HMF), HMF itself is currently produced in limited volume from mono- and polysaccharides like glucose and fructose, thus blocking the utilization of FDCA to replace p-phthalic acid as monomer in industrial applications. This work presents an alternative route for FDCA synthesis originally from renewable furfural through carbonylation of 5-bromofuroic acid with common palladium catalysts, which achieves >99% yield of FDCA based on HPLC analysis, or above 90% isolated yield in gram scale. The influences of the palladium sources, phosphine ligands and bases were investigated in details, and a simplified mechanism was also presented. [ABSTRACT FROM AUTHOR]

[Display omitted] • H 2 O 2 is used as the solely terminal oxidant in the alkene epoxidation. • Lewis acids remarkably promote the alkene epoxidation efficiency of sluggish manganese catalyst under mild conditions. • The promotional effect by Lewis acid was induced by dissociating torpid Mn-(μ-O) 3 -Mn core. This work demonstrates a novel strategy that the introduction of non-redox metal ions as Lewis acids to the classic dinuclear manganese complex [MnIV 2 (μ-O) 3 (Me 3 tacn) 2 ](PF 6) 2 can greatly promote the alkene epoxidation efficiency under mild conditions with H 2 O 2 as the solely terminal oxidant because of its economic and environmental advantages. When [MnIV 2 (μ-O) 3 (Me 3 tacn) 2 ](PF 6) 2 was used as the catalyst in the absence of Lewis acids, only 16.4% conversion of cyclooctene with 6.2% yield of epoxide was obtained and the obvious decomposition of H 2 O 2 was observed. However, the oxygen transfer efficiency of the catalyst was sharply improved with 100% conversion and 90.2% yield of epoxide under identical conditions when the non-redox metal ion, such as Sc3+, was introduced to the catalytic system. The novel strategy was successfully applied to the epoxidation reactions of different types of alkenes. Through UV–vis, FT-IR, EPR and CV characterizations, it was evidenced that the non-redox metal ions with high positive charge as Lewis acids could dissociate the sluggish dinuclear Mn-(μ-O) 3 -Mn core and the open-loop dinuclear manganese complex, HO-MnIII-(μ-O)-MnIV = O or O = MnIV-(μ-O)-MnIV = O, was proposed as the active species, which was capable of the alkene epoxidation process. This work illustrated an alternative protocol to manipulate the reactivity of those sluggish catalysts by the introduction of non-redox metal ions and provided clues to understand the role of non-redox metal ions in metalloenzymes and heterogeneous catalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • Flexible films of main-chain LLCPs can be achieved by introducing renewable biobased bifuran units. • The AIE-active mesogens on LLCPs backbone undergo Z / E photoisomerization in solution and [2 + 2] cycloaddition in film. • Fluorescent patterns can be printed on the films through the cycloaddition behavior. Luminescent liquid crystalline polymers (LLCPs) have attracted great attention due to their potential applications in liquid crystal display, optical memory storage, organic light-emitting diode, and other fields. However, the fluorescence signals of LLCPs bearing conventional luminophores showing aggregation-caused quenching behavior are strikingly diminished or even vanish in the aggregated state. Herein, we have synthesized three main-chain LLCPs with α-cyanostilbene (CS) and bifuran units connected by different flexible spacer lengths via melt polycondensation. On the one hand, the CS unit acts as a rigid rod-like mesogen with aggregation-induced emission (AIE) characteristics. On the other hand, the renewable biobased bifuran moiety has been chosen because of two main reasons. One is it is a perfect alternative to the rigid fossil-based biphenyl group. The other reason is the addition of bifuran moiety is beneficial for the polycondensation and the extension of the chain length, leading to the enhancement of the toughness of LLCPs. Upon 365 nm UV light irradiation, these polymers undergo an irreversible Z/E isomerization in solution, while the [2 + 2] cycloaddition of CS chromophores occurs in the solid film. Importantly, the polymers display a good film-forming ability, so that the flexible thin films can be achieved by ordinary compression molding. Moreover, the fluorescent patterns can be directly printed on the flexible films on the basis of the [2 + 2] cycloaddition behavior, which shows their promising applications ranging from information storage to high-tech anti-counterfeiting. [ABSTRACT FROM AUTHOR]

[Display omitted] • Lewis and Brønsted acids can sharply improve the oxygen transfer efficiency of a manganese(II) catalyst with non-heme ligand. • The catalytic activity improvement is acidity strength or net charge dependent. • The promotional effect by either Lewis acid or Brønsted acid was originated from the dissociating sluggish di-μ-oxo core. • Distinctions of reactive intermediate were also demonstrated for Lewis acid or Brønsted acid. This work demonstrates that certain Lewis and Brønsted acids can sharply improve the oxygen transfer efficiency of a manganese(II) catalyst bearing non-heme ligand. In the absence of Lewis and Brønsted acids, oxidation of manganese(II) complex will generate di-μ-oxo-bridged dinuclear Mn 2 (III,IV) core which is very sluggish for olefin epoxidation. Adding non-redox metal ions as Lewis acid or Brønsted acid will both improve the catalytic epoxidation of olefin, and this improvement is dependent on the pK a of Brønsted acid, or the net charge of non-redox metals of Lewis acid. Mechanism study revealed that similar promotional effect by either Lewis or Brønsted acids was originated from a similar reaction pathway by dissociating aforementioned sluggish di-μ-oxo core. However, distinctions of reactive intermediate were also demonstrated for Lewis or Brønsted acids. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synergetic effect led to remarkably improved performances in various dehydrogenation reactions. • The catalytic activity improvement is Lewis acidity strength dependent. • Dioxygen was used as the solely terminal oxidant under mild conditions. • An adduct of Ru(IV) = O/Sc(III) was proposed as the key active species to improve the catalytic efficiency. Dioxygen activation as the solely terminal oxidant in organic synthesis and catalytic oxidation is particularly attractive from the point of economic and environmental view. In our previous study, we have displayed that the introducing of non-redox metal ions can sharply improve the olefin epoxidation catalyzed by ruthenium complex with PhI(OAc) 2 as the organic oxidation. Inspired by the successful strategy and dioxygen activation, in this study, we demonstrate an alternative protocol that adding non-redox metal ions to cis -Ru(bpy) 2 Cl 2 catalyst can remarkably improve the oxidation from Ru(II) to Ru(IV) = O with dioxygen as the oxidant and promote oxidative dehydrogenation of saturated C–C bond whereas Ru(bpy) 2 Cl 2 alone is very sluggish. Through UV–Vis, NMR, cyclic voltammogram and EPR characterization, it has been testified that oxidation from Ru(II) to Ru(IV) = O can be realized under the condition of 1 atm of dioxygen and 323 K within 25 min while extreme tough condition of 20 atm of dioxygen, 343 K and 8 h is necessary for Ru(bpy) 2 Cl 2 alone. Combined the reaction data with characterization results, an adduct of Ru(IV) = O/Sc(III) is proposed as the key active species to improve the catalytic efficiency. The activity improvement in oxidative dehydrogenation illustrated a novel strategy of that adding non-redox metal ions to sluggish catalysts can remarkably improve its efficiency for dehydrogenation of saturated C–C bond, especially through dioxygen as ultimate oxidant. [ABSTRACT FROM AUTHOR]

Redox metal ions play the crucial role in versatile advanced oxidation technologies, in which controlling the active species formation through catalyst design is one of the key challenges in oxidant utilization. This work describes an example of different active species formations in CuO-mediated degradation just because of supporting material differences. Although three CuO catalysts were prepared by similar procedures, it was found that CuO-MgO catalyst demonstrated high efficiency in phenol degradation with bicarbonate activated H 2 O 2 , in which the superoxide radical is crucial, while hydroxyl radical and singlet oxygen are ignorable. For the CuO-MgO-Al 2 O 3 and CuO-Al 2 O 3 catalysts, the degradation proceeds by popular hydroxyl radical based process, however, the efficiency was poor. The EPR experiments also confirmed the absence of hydroxyl radical in CuO-MgO system but its presence in CuO-MgO-Al 2 O 3 and CuO-Al 2 O 3 system. The high catalytic efficiency with ignorable hydroxyl radical in the CuO-MgO system leads us to propose that an alternative Cu(III) species dominates the degradation. The basic MgO support may facilitate the formation of the Cu(III) species, whereas the neutral MgO-Al 2 O 3 and acidic Al 2 O 3 supports are unable to stabilize the high valent Cu(III) species, leading to the common hydroxyl radical mechanism with low efficiency of H 2 O 2 in alkaline conditions. [ABSTRACT FROM AUTHOR]

Transition-metal-catalyzed oxidative C–H olefination/annulation reactions are among the most attractive topics in organic synthesis to construct heterocyclic compounds. The challenge is that, in order to achieve satisfied catalytic efficiencies, most of these syntheses employed stoichiometric oxidants. Herein, we report a Pd(II)/LA-catalyzed (LA: Lewis acid) oxidative C–H olefination/annulation reaction of N -Ts-2-arylanilines with activated olefins to synthesize dihydrophenanthridines by using dioxygen balloon as the sole oxidant source, and the presence of LA sharply improved the catalytic efficiency of Pd(OAc) 2. The mechanistic studies by using in situ generated palladacycle compound as the catalyst for the substrate H/D exchange disclosed that the C–H activation by Pd(II) was a reversible step. However, in the catalytic C–H olefination/annulation reaction, whether deuterium from solvent being incorporated into the recycled substrate was highly dependent on the aromatic electronic effect of the substrates. [Display omitted] [ABSTRACT FROM AUTHOR]

Correction for 'Lewis acid improved dioxygen activation by a non-heme iron(II) complex towards tryptophan 2,3-dioxygenase activity for olefin oxygenation' by Guangjian Liao et al., Dalton Trans., 2022, https://doi.org/10.1039/d2dt02769k. [ABSTRACT FROM AUTHOR]

The effluents from industries are commonly non-biodegradable and produce various hazardous intermediate products by chemical reactions that have direct impact on environment. In the present investigation, a series of Co–Mg/AL ternary LDH catalysts with fixed Mg/Al ratio were prepared by co-precipitation method. The effect of Co on the activity of the catalyst was monitored on the degradation of methylene blue (MB) as model compound at batch level using bicarbonate activation of H 2 O 2 (BAP) system. On bench level, the best CoMgAl-4 catalyst can completely decolorize both methylene blue (MB) and methylene orange (MO) in short time, while in fixed bed, the catalyst was found stable for over 300 h with nearly 100% decolorization and excellent chemical oxygen demand (COD) removal. No leaching of Co was detected for the entire fixed experiment which may be accounted for long life stability and good activity of the catalyst. The ternary LDH catalysts were characterized by AES, XRD, FTIR, BET, and SEM for its compositional, phase structure, optical properties, textural, and surface morphology respectively. The XRD analysis confirmed characteristic pattern of hydrotalcite like structures without impurity phases. The formation of superoxide and hydroxyl radical as ROS was proposed with CoMgAl-4 by radical’s scavengers. [ABSTRACT FROM AUTHOR]

• Bifurfural was obtained from 5-bromofurfural with 98% yield. • The catalyst is commercially available and recycable. • It provides a promising market for furfural and CO utilizations. Deriving versatile monomers from bulky biomass for polymer production can greatly replace fossil resources as the carbon source of chemical industry. The present studies introduce the feasible synthesis of bifurfural, a bifunctionalized bifuran monomer, from the furfural platform. The reaction was carried out through reductive coupling of 5-bromofurfural with CO as the reductant source with commercial Pd/C as the catalyst under gentle conditions, and the catalyst is recyclable and reusable. So prepared bifurfural was preliminarily investigated as a monomer for poly(Schiff base) material synthesis, and it was found that the poly(Schiff base) derived from nonlinear bifurfural monomer polymerizing with linear p -phenylenediamine demonstrated larger surface area than that from petrochemical 4,4′-biphenyldicarboxaldehyde with excellent thermal stability, thus offering a new opportunity in bifurfural based furfural utilization in polymer industry. Bifurfural was prepared through reductive coupling of renewable furfural derived 5-bromofurfural with CO as reductant and commercial Pd/C as catalyst under gentle condition s, and the catalyst is recyclable and reusable [Display omitted]. [ABSTRACT FROM AUTHOR]