Microwave-assisted dehydration of D-xylose into furfural by diluted inexpensive inorganic salts solution in a biphasic system

Coupling process for preparing biomass-based furfural and levulinic acid from corncob: Extraction, green chemistry and techno-economic assessment

The purpose of this study is to design and investigate two coupling processes for acid-catalyzed hydrolysis of corncob, achieving the simultaneous preparation of biomass-based furfural and levulinic acid (LA). Meanwhile, high concentration and yield of LA were obtained through a situ feeding strategy of pretreated furfural residue with high solids loading (20%, w/v). In Scenario A, 2-methyltetrahydrofuran was selected as the solvent for the LA extraction process compared with the neutralization process in Scenario B. Techno-economic assessment results show that Scenario A is technically feasible and cost-competitive, with an internal rate of return of 21.92%, a net present value of 121 million US dollars, a carbon efficiency of 72%, an environmental factor of 4.38, and a process mass intensity of 32.19. This study will provide new insights for fully utilizing lignocellulosic biomass to prepare renewable energy resources, comprehensively evaluating the economic feasibility, and promoting green and low-carbon development.

Efficient synthesis of furfurylamine from biomass via a hybrid strategy in an EaCl:Gly–water medium

The objective of this work was to develop an efficient approach for chemoenzymatically transforming biomass to furfurylamine by bridging chemocatalysis and biocatalysis in a deep eutectic solvent of EaCl:Gly–water. Using hydroxyapatite (HAP) as support, heterogeneous catalyst SO42−/SnO2–HAP was synthesized for transforming lignocellulosic biomass into furfural using organic acid as a co-catalyst. The turnover frequency (TOF) was correlated with the pKa value of the used organic acid. Corncob was transformed by oxalic acid (pKa = 1.25) (0.4 wt%) plus SO42−/SnO2–HAP (2.0 wt%) to produce furfural with a yield of 48.2% and a TOF of 6.33 h-1 in water. In deep eutectic solvent EaCl:Gly–water (1:2, v/v), co-catalysis with SO42−/SnO2–HAP and oxalic acid was utilized to transform corncob, rice straw, reed leaf, and sugarcane bagasse for the production of furfural with the yield of 42.4%–59.3% (based on the xylan content) at 180°C after 10 min. The formed furfural could be efficiently aminated to furfurylamine with E. coli CCZU-XLS160 cells in the presence of NH4Cl (as an amine donor). As a result of the biological amination of furfural derived from corncob, rice straw, reed leaf, and sugarcane bagasse for 24 h, the yields of furfurylamine reached >99%, with a productivity of 0.31–0.43 g furfurylamine per g xylan. In EaCl:Gly–water, an efficient chemoenzymatic catalysis strategy was employed to valorize lignocellulosic biomass into valuable furan chemicals.

Microwave-assisted choline chloride/1,2-propanediol/methyl isobutyl ketone biphasic system for one-pot fractionation and valorization of Eucalyptus biomass

The developing of pretreatment method to break the biomass barrier of lignocellulosic is a challenging task for achieve high value utilization. A fast microwave-assisted choline chloride/1,2-propanediol/methyl isobutyl ketone biphasic system was constructed for pretreating Eucalyptus to the production of furfural and cellulose-rich residues and the extraction of lignin. Results showed that the combination of AlCl₃·6H₂O and HCl had the best catalytic ability for furfural production among the examined catalysts. Under the optimal conditions (140 °C, 15 min, 0.075 M AlCl₃·6H₂O, 0.05 M HCl), the furfural yield of 55.4 %, the glucose yield of 90.3 % and the delignification rate of 92.4 % could be achieved. Moreover, the extracted lignin samples with a low polydispersity (1.55-1.73) and molecular weight (1380-2040 g/mol) are promising to act as precursor for the value-add products processing. These findings demonstrated an ultrafast pretreatment process with excellent results in biomass fractionation and comprehensive utilization of biomass components.

Towards efficient and greener processes for furfural production from biomass: A review of the recent trends

As mentioned in several recent reviews, biomass-based furfural is attracting increasing interest as a feasible alternative for the synthesis of a wide range of non-petroleum-derived compounds. However, the lack of environmentally friendly, cost-effective, and sustainable industrial procedures is still evident. This review describes the chemical and biological routes for furfural production. The mechanisms proposed for the chemical transformation of xylose to furfural are detailed, as are the current advances in the manufacture of furfural from biomass. The main goal is to overview the different ways of improving the furfural synthesis process. A pretreatment process, particularly chemical and physico-chemical, enhances the digestibility of biomass, leading to the production of >70 % of available sugars for the production of valuable products. The combination of heterogeneous (zeolite and polymeric solid) catalyst and biphasic solvent system (water/GVL and water/CPME) is regarded as an attractive approach, affording >75 % furfural yield for over 80 % of selectivity with the possibility of catalyst reuse. Microwave heating as an activation technique reduces reaction time at least tenfold, making the process more sustainable. The state of the art in industrial processes is also discussed. It shows that, when sulfuric acid is used, the furfural yields do not exceed 55 % for temperatures close to 180 °C. However, the MTC process recently achieved an 83 % yield by continuously removing furfural from the liquid phase. Finally, the CIMV process, using a formic acid/acetic acid mixture, has been developed. The economic aspects of furfural production are then addressed. Future research will be needed to investigate scaling-up and biological techniques that produce acceptable yields and productivities to become commercially viable and competitive in furfural production from biomass.

Evaluation of Acidic Ionic Liquids as Catalysts for Furfural Production from Eucalyptus nitens Wood

Eucalyptus nitens wood samples were subjected to hydrothermal processing to obtain soluble saccharides from the hemicellulosic fraction. The hemicellulose-derived saccharides were employed as substrates for furfural production in biphasic media made up of water, methyl isobutyl ketone, and one acidic ionic liquid (1-butyl-3-methylimidazolium hydrogen sulfate or 1-(3-sulfopropyl)-3-methylimidazolium hydrogen sulfate). The reactions were carried out in a microwave-heated reactor to assess the effects of the most influential variables. Under selected operational conditions, the molar conversions of the precursors into furfural were within the range of 77–86%. The catalysts conserved their activity after reutilization in five consecutive reaction cycles.

Enhanced Furfural Production in Deep Eutectic Solvents Comprising Alkali Metal Halides as Additives

The addition of alkali metal halide salts to acidic deep eutectic solvents is here reported as an effective way of boosting xylan conversion into furfural. These salts promote an increase in xylose dehydration due to the cation and anion interactions with the solvent being a promising alternative to the use of harsh operational conditions. Several alkali metal halides were used as additives in the DES composed of cholinium chloride and malic acid ([Ch]Cl:Mal) in a molar ratio of 1:3, with 5 wt.% of water. These mixtures were then used as both solvent and catalyst to produce furfural directly from xylan through microwave-assisted reactions. Preliminary assays were carried out at 150 and 130 °C to gauge the effect of the different salts in furfural yields. A Response Surface Methodology was then applied to optimize the operational conditions. After an optimization of the different operating conditions, a maximum furfural yield of 89.46 ± 0.33% was achieved using 8.19% of lithium bromide in [Ch]Cl:Mal, 1:3; 5 wt.% water, at 157.3 °C and 1.74 min of reaction time. The used deep eutectic solvent and salt were recovered and reused three times, with 79.7% yield in the third cycle, and the furfural and solvent integrity confirmed.

Innovative Protocols in the Catalytic Oxidation of 5-Hydroxymethylfurfural

5-Hydroxymethylfurfural (HMF) has been identified as one of the most promising biomass-based multi-purpose platform molecules. Innovative protocols, namely electrocatalysis, photocatalysis, and microwave (MW)-assisted chemistry, as well as continuous-flow systems, add a new dimension and another promising toolbox for the oxidation of HMF in recent years. This Minireview deals with recent progress in the catalytic oxidation of HMF to 2,5-furandicarboxylic acid (FDCA) and other intermediates using noble, non-noble, and metal-free systems deploying emerging protocols. Selective HMF downstream oxidation products could be obtained not only via common catalyst modifications, namely nature of the metal, preparative method, and the property of deployed support, but also by using innovative processes.

Chemoenzymatic conversion of Sorghum durra stalk into furoic acid by a sequential microwave-assisted solid acid conversion and immobilized whole-cells biocatalysis

In this study, chemoenzymatic conversion of Sorghum durra stalk (SDS) into furoic acid was developed by a sequential microwave-assisted solid acid conversion and immobilized whole-cells biocatalysis method. Dry dewaxed SDS (75 g/L) was catalyzed into furfural at 57.8% yield with heterogeneous Sn-argil (2.0 wt% dosage) in n-ethyl butyrate-H₂O (1:1, v:v) biphasic system using a microwave (600 W) for 10 min at 180 °C. In this biphasic media (pH 6.5), SDS-derived furfural (125.0 mM) was biologically oxidized to furoic acid by immobilized Brevibacterium lutescens cells harboring furfural-oxidizing activity at 30 °C, and furfural was wholly transformed to furoic acid within 24 h. Finally, the recovery and reuse of the Sn-argil catalyst and immobilized biocatalysts were conducted for synthesizing furoic acid from SDS in the biphasic system. This chemoenzymatic route can be attractive for furoic acid production.

Optimization with Response Surface Methodology of Microwave-Assisted Conversion of Xylose to Furfural

The production of furfural from renewable sources, such as lignocellulosic biomass, has gained great interest within the concept of biorefineries. In lignocellulosic materials, xylose is the most abundant pentose, which forms the hemicellulosic part. One of the key steps in the production of furfural from biomass is the dehydration reaction of the pentoses. The objective of this work was to assess the conditions under which the concentration of furfural is maximized from a synthetic, monophasic, and homogeneous xylose medium. The experiments were carried out in a microwave reactor. FeCl3 in different proportions and sulfuric acid were used as catalysts. A two-level, three-factor experimental design was developed for this purpose. The results were further analyzed through a second experimental design and optimization was performed by response surface methodology. The best operational conditions for the highest furfural yield (57%) turned out to be 210 °C, 0.5 min, and 0.05 M FeCl3.

Conversion of Xylose to Furfural over Lignin-Based Activated Carbon-Supported Iron Catalysts

In this study, conversion of xylose to furfural was studied using lignin-based activated carbon-supported iron catalysts. First, three activated carbon supports were prepared from hydrolysis lignin with different activation methods. The supports were modified with different metal precursors and metal concentrations into five iron catalysts. The prepared catalysts were studied in furfural production from xylose using different reaction temperatures and times. The best results were achieved with a 4 wt% iron-containing catalyst, 5Fe-ACs, which produced a 57% furfural yield, 92% xylose conversion and 65% reaction selectivity at 170 °C in 3 h. The amount of Fe in 5Fe-ACs was only 3.6 µmol and using this amount of homogeneous FeCl3 as a catalyst, reduced the furfural yield, xylose conversion and selectivity. Good catalytic activity of 5Fe-ACs could be associated with iron oxide and hydroxyl groups on the catalyst surface. Based on the recycling experiments, the prepared catalyst needs some improvements to increase its stability but it is a feasible alternative to homogeneous FeCl3.

Furfural Analogs as Sustainable Corrosion Inhibitors—Predictive Efficiency Using DFT and Monte Carlo Simulations on the Cu(111), Fe(110), Al(111) and Sn(111) Surfaces in Acid Media

Nowadays, theoretical calculation tools have become powerful in predicting the behavior of corrosion inhibitors on the surface of metals and, therefore, avoiding energy consumption and the cost of experimental tests. This work aims to predict the inhibitory power of some furan derivatives on Cu (111), Fe (110), Al (111) and Sn (111) surfaces in acidic media. For this purpose, three furan derivatives—furan-2-carbaldehyde (FF1), 5-(hydroxymethyl)furfural (FF2) and 5-(hydroxymethyl)furoic acid (FF3)—have been selected to compare their intrinsic properties against corrosion as well as their behavior on iron (Fe), copper (Cu), aluminum (Al) and tin (Sn) surfaces in acid medium. Typically, the anti-corrosive properties of FF1, FF2 and FF3 were studied by using quantum chemical calculations and Monte Carlo simulations. Density Functional Theory (DFT), lowest unoccupied (ELUMO) and highest occupied (EHOMO) molecular orbital energies, energy gap (∆E), chemical hardness (η), softness (σ), electronegativity (χ), electrophilicity (ω) and nucleophilicity (ε) have been calculated and discussed. Theoretical vibrational spectra were also calculated to exhibit the functional groups in the selected chemicals. On the other hand, the adsorption behaviors of FF1, FF2 and FF3 were studied on the Fe(110), Cu(111), Al(111) and Sn(111) surfaces. As a result, the adsorption energies of all molecules are ordered as Fe(110) < Cu(111) < Al(111) < Sn(111) and FF3 seems to be more effective as a corrosion inhibitor due to the existence of both carboxylic acid and hydroxyl groups, which consist of favorable sites of adsorption into the metal surface.

Selective production of furfural from the dehydration of xylose using Zn doped CuO catalyst

Furfural is a versatile biomass-derived platform compound used for the synthesis of several strategic chemicals. The sonochemically synthesized Zn doped CuO nanoparticles (NPs) were used for the production of furfural. The catalytic activity of the Zn doped CuO NPs was examined, as a model, during the dehydration reaction of xylose to furfural. In addition to that, we have also compared the catalytic activity of the Zn doped CuO NP with ZnO NPs, ZnO bulk, CuO NPs, CuO bulk, etc. This nanoscale catalyst (Zn doped CuO NP) has a large surface area, which enhances its catalytic activity and enables it to completely convert the xylose to furfural at 150 °C within 12 h without any trace of by-products, as confirmed by HPLC, ¹³C NMR and ¹H NMR. HPLC analysis demonstrated that the yield of furfural is up to 86 mol %, compared to the 45 mol % obtained with ZnO NPs, ZnO bulk, CuO NPs, CuO bulk, etc. as catalysts.

Cyclopentyl Methyl Ether (CPME): A Versatile Eco-Friendly Solvent for Applications in Biotechnology and Biorefineries

The quest for sustainable solvents is currently a matter of intense research and development, as solvents significantly contribute heavily to the waste generated by chemical industries. Cyclopentyl methyl ether (CPME) is a promising eco-friendly solvent with valuable properties such as low peroxide formation rate, stability under basic and acidic conditions, and relatively high boiling point. This Review discusses the potential use of CPME for applications in biotechnology (e.g., biotransformations, as solvent or cosolvent), biorefineries, and bioeconomy (e.g., for furan synthesis or as an extractive agent in liquid-liquid separations), as well as for other purposes, such as chromatography or peptide synthesis. Although CPME is currently produced by petrochemical means with a remarkably high atom economy, its biogenic production can be envisaged from substrates such as cyclopentanol or cyclopentanone, which can be derived from furfural or from (bio-based) adipic acid, respectively. The combination of the promising properties of CPME as a (co)solvent with a future (economic) biogenic origin would be advantageous for setting strategies aligned with the sustainable chemistry principles.

One-pot co-catalysis of corncob with dilute hydrochloric acid and tin-based solid acid for the enhancement of furfural production

A newly synthesized solid acid catalyst SO₄^2-/SnO₂-diatomite was prepared for synthesizing furfural from corncob in the presence of homogeneous Brönsted acid. The relationship between pKa of Brönsted acid and turnover frequency (TOF) of co-catalysis with Brönsted acid plus SO₄^2-/SnO₂-diatomite was explored on the conversion of corncob to furfural. HCl (pKa = -7.0) (0.5 wt%) plus SO₄^2-/SnO₂-diatomite (3.6 wt%) gave the highest furfural yield (40.1%) with TOF value at 2.98 h^-1 in the aqueous media. In the γ-valerolactone-water (6:4, v:v) biphasic media containing 15 g/L ZnCl₂, one-pot conversion of corncob with co-catalysts gave a furfural yield of 68.9% at 170 °C for 30 min. Additionally, an efficient SO₄^2-/SnO₂-diatomite recycling was achieved with a productivity of 15.6 g furfural/(g solid acid·day) after 5 cycles of repeated use. Clearly, this one-pot co-catalysis process has high potential application for furfural production in future.

Recent Advances in the Microwave-Assisted Production of Hydroxymethylfurfural by Hydrolysis of Cellulose Derivatives-A Review

The concepts of sustainable development, bioeconomy, and circular economy are being increasingly applied for the synthesis of molecules of industrial interest. Among these molecules, hydroxymethylfurfural as a platform molecule is the subject of various research approaches to improve its synthesis and productivity, and extend its potential uses. Accordingly, this review paper aims essentially at outlining recent breakthroughs obtained in the field of hydroxymethylfurfural production from sugars and polysaccharide feedstocks under microwave-assisted technology. The review discusses advances obtained via microwave activation in major production pathways recently explored, split into the following categories: (i) use of various homogeneous catalysts like mineral or organic acids, metal salts, or ionic liquids; (ii) feedstock dehydration making use of various solid acid catalysts; and (iii) non-catalytic routes.

Microwaves in the Catalytic Valorisation of Biomass Derivatives

The application of microwave irradiation in the transformation of biomass has been receiving particular interest in recent years due to the use of polar media in such processes and it is now well-known that for biomass conversion, and particularly for lignocellulose hydrolysis, microwave irradiation can dramatically increase reaction rates with no negative consequences on product selectivity. However, it is only in the last ten years that the utilisation of microwaves has been coupled with catalysis aiming towards valorising biomass components or their derivatives via a range of reactions where high selectivity is required in addition to enhanced conversions. The reduced reaction times and superior yields are particularly attractive as they might facilitate the transition towards flow reactors and intensified production. As a consequence, several reports now describe the catalytic transformation of biomass derivatives via hydrogenation, oxidation, dehydration, esterification and transesterification using microwaves. Clearly, this technology has a huge potential for biomass conversion towards chemicals and fuels and will be an important tool within the biorefinery toolkit. The aim of this chapter is to give the reader an overview of the exciting scientific work carried out to date where microwave reactors and catalysis are combined in the transformation of biomass and its derivatives to higher value molecules and products.

Hydrolysis of Hemicellulose and Derivatives-A Review of Recent Advances in the Production of Furfural

Biobased production of furfural has been known for decades. Nevertheless, bioeconomy and circular economy concepts is much more recent and has motivated a regain of interest of dedicated research to improve production modes and expand potential uses. Accordingly, this review paper aims essentially at outlining recent breakthroughs obtained in the field of furfural production from sugars and polysaccharides feedstocks. The review discusses advances obtained in major production pathways recently explored splitting in the following categories: (i) non-catalytic routes like use of critical solvents or hot water pretreatment, (ii) use of various homogeneous catalysts like mineral or organic acids, metal salts or ionic liquids, (iii) feedstock dehydration making use of various solid acid catalysts; (iv) feedstock dehydration making use of supported catalysts, (v) other heterogeneous catalytic routes. The paper also briefly overviews current understanding of furfural chemical synthesis and its underpinning mechanism as well as safety issues pertaining to the substance. Eventually, some remaining research topics are put in perspective for further optimization of biobased furfural production.

Microemulsion and Sol-Gel Synthesized ZrO₂-MgO Catalysts for the Liquid-Phase Dehydration of Xylose to Furfural

Two series of catalysts were prepared by sol-gel and microemulsion synthetic procedure (SG and ME, respectively). Each series includes both pure Mg and Zr solids as well as Mg-Zr mixed solids with 25%, 50% and 75% nominal Zr content. The whole set of catalysts was characterized from thermal, structural and surface chemical points of view and subsequently applied to the liquid-phase xylose dehydration to furfural. Reactions were carried out in either a high-pressure autoclave or in an atmospheric pressure multi-reactor under a biphasic (organic/water) reaction mixture. Butan-2-ol and toluene were essayed as organic solvents. Catalysts prepared by microemulsion retained part of the surfactant used in the synthetic procedure, mainly associated with the Zr part of the solid. The MgZr-SG solid presented the highest surface acidity while the Mg3Zr-SG one exhibited the highest surface basicity among mixed systems. Xylose dehydration in the high-pressure system and with toluene/water solvent mixture led to the highest furfural yield. Moreover, the yield of furfural increases with the Zr content of the catalyst. Therefore, the catalysts constituted of pure ZrO₂ (especially Zr-SG) are the most suitable to carry out the process under study although MgZr mixed solids could be also suitable for overall processes with additional reaction steps.

Catalytic conversion of corncob and corncob pretreatment hydrolysate to furfural in a biphasic system with addition of sodium chloride

Catalytic conversion of corncob pretreatment hydrolysate and raw corncob into furfural in a modified biphasic system by SO₄^2-/SnO₂^- MMT solid catalyst has been developed. The influence of the organic solvent type, organic to water phase ratio, sodium chloride concentration, reaction temperature and time on the furfural production were comparatively evaluated. The results showed that furfural yields of 81.7% and 66.1% were achieved at 190°C for 15mins and 190°C for 20mins, respectively, for corncob pretreatment hydrolysate and raw corncob by this solid catalyst. The solid catalyst used in this study exhibited good stability and high efficiency applied in the modified biphasic system in addition to excellent recyclability. The proposed catalytic system displayed high performance for catalytic conversion of lignocellulosic biomass into important platform chemicals and has great potential in industrial application.

Synergy of Lewis and Brønsted acids on catalytic hydrothermal decomposition of carbohydrates and corncob acid hydrolysis residues to 5-hydroxymethylfurfural

5-hydroxymethylfurfural (HMF) is an important platform molecule in the synthesis of various chemicals and materials. Herein, we reported a simple and effective dehydration of glucose-based carbohydrates to HMF in a biphasic system containing cyclopentyl methyl ether as the organic phase and AlCl₃ with minute amounts of HCl as co-catalysts. The results showed that the mixed catalysts had a positive synergistic catalytic effect on glucose conversion to HMF compared with single AlCl₃ or HCl catalyst. For glucose, the highest HMF yield of 54.5% was achieved at 175 °C for 20 min. More importantly, the optimal catalytic system was so efficient that it achieved one of the highest reported yields of HMF (30.5%) directly from corncob acid hydrolysis residues. Thus, the catalytic system can become a promising route for effective utilization of biomass in future biorefineries.

Production of furfural from xylose and corn stover catalyzed by a novel porous carbon solid acid in γ-valerolactone

An efficient catalytic system using S-RFC as catalyst was developed to produce furfural from xylose and corn stover in GVL.

Furfural Synthesis from d-Xylose in the Presence of Sodium Chloride: Microwave versus Conventional Heating

We investigate the existence of specific/nonthermal microwave effects for the dehydration reaction of xylose to furfural in the presence of NaCl. Such effects are reported for sugars dehydration reactions in several literature reports. To this end, we adopted three approaches that compare microwave-assisted experiments with a) conventional heating experiments from the literature; b) simulated conventional heating experiments using microwave-irradiated silicon carbide (SiC) vials; and at c) different power levels but the same temperature by using forced cooling. No significant differences in the reaction kinetics are observed using any of these methods. However, microwave heating still proves advantageous as it requires 30 % less forward power compared to conventional heating (SiC vial) to achieve the same furfural yield at a laboratory scale.

Furfural Production from d-Xylose and Xylan by Using Stable Nafion NR50 and NaCl in a Microwave-Assisted Biphasic Reaction

Pentose dehydration and direct transformation of xylan into furfural were performed in a water-cyclopentyl methyl ether (CPME) biphasic system under microwave irradiation. Heated up between 170 and 190 °C in the presence of Nafion NR50 and NaCl, d-xylose, l-arabinose and xylan gave furfural with maximum yields of 80%, 42% and 55%, respectively. The influence of temperature and reaction time on the reaction kinetics was discussed. This study was also completed by the survey of different reactant ratios, such as organic layer-water or catalyst-inorganic salt ratios. The exchange between proton and cation induced by an excess of NaCl was monitored, and a synergetic effect between the remaining protons and the released HCl was also discovered.

A one-pot synthesis of 1,6,9,13-tetraoxadispiro(4.2.4.2)tetradecane by hydrodeoxygenation of xylose using a palladium catalyst

In an effort to expand the number of biobased chemicals available from sugars, xylose has been converted to 1,6,9,13-tetraoxadispiro(4.2.4.2)tetradecane in a one-pot reaction using palladium supported on silica-alumina as the catalyst. The title compound is produced in 35-40% yield under 7 MPa H2 pressure at 733 K using 3-10 wt%Pd on silica-alumina catalyst. It is isolated using a combination of liquid-liquid extractions and flash chromatography. This dimer can be converted to its monomer, 2-hydroxy-(2-hydroxymethyl)tetrahydrofuran, which ring opens under acid conditions to 1,5-dihydroxy-2-pentanone. This diol can then be esterified with vinylacetate in phosphate buffer to produce 1,5-bis(acetyloxy)-2-pentanone which is an inhibitor of mammalian 11β-hydroxysteroid dehydrogenase 1. (1)H and (13)C nmr spectra of each of these species are reported. The single crystal X-ray structure of the title compound is also reported. These data were collected in a temperature range of 100 K-273 K and show a solid state phase change from triclinic to monoclinic between 175 K and 220 K without a conformational change.

Design for carbon–carbon bond forming reactions under ambient conditions

The carbon–carbon (C–C) bond forms the ‘backbone’ of nearly every organic molecule, and lies at the heart of the chemical sciences! Let us explore designing of carbon–carbon frameworks at ambient conditions.