An efficient and high-water-content enzymatic esterification method for the synthesis of ß-sitosterol conjugated linoleate via a sodium citrate-based three-liquid-phase system.

Three-liquid-phase systems (TLPSs) are novel interfacial enzymatic reaction systems that have been successfully applied in many valuable reactions. However, these systems are suitable only for hydrolysis reactions and not for more widely used esterification reactions. Surprisingly, our recent research revealed that two water-insoluble substrates (ß-sitosterol and conjugated linoleic acid) could be rapidly esterified in this system. The initial rate of the esterification reaction in the TLPS based on sodium citrate was enhanced by approximately 10-fold relative to that in a traditional water/n-hexane system. The special emulsion structure (S/W1/W2 emulsion) formed may be vital because it not only provides a larger reaction interface but also spontaneously generates a middle phase that might regulate water activity to facilitate esterification. Furthermore, the lipase-enriched phase could be reused at least 8 times without significant loss of catalytic efficiency. Therefore, this TLPS is an ideal enzymatic esterification platform for ester synthesis because it is efficient, convenient to use, and cost-effective.

Development and Characterization of Bio-Based Formaldehyde Free Sucrose-Based Adhesive for Fabrication of Plywood.

In order to solve the problem of excessive consumption of petrochemical resources and the harm of free formaldehyde release to human health, biomass raw materials, such as sucrose (S) and ammonium dihydrogen phosphate (ADP) can be chemically condensed in a simple route under acidic conditions to produce a formaldehyde free wood adhesive (S-ADP), characterized by good storage stability and water resistance, and higher wet shear strength with respect to petroleum based phenolic resin adhesive. The dry and boiling shear strength of the plywood based on S-ADP adhesive are as high as 1.05 MPa and 1.19 MPa, respectively. Moreover, is Modulus of Elasticity (MOE) is as high as 4910 MPa. Interestingly, the plywood based on the developed S-ADP adhesive exhibited good flame retardancy. After burning for 90 s, its shape remains unchanged. Meanwhile, it can be concluded from thermomechanical analysis (TMA) and thermogravimetric analysis (TGA) that the S-ADP acquired excellent modulus of elasticity (MOE) and good thermal stability. It is thus thought promisingly that the use of S-ADP adhesive as a substitute for PF resin adhesive seems feasible in the near future.

A new integrated strategy for high purity pinolenic acid production from Pinus koraiensis Sieb. et Zucc seed oil and evaluation of its hypolipidemic activity in vivo.

Pinolenic acid is a polyunsaturated fatty acid present only in Pinus koraiensis Sieb. et Zucc seed oil. In order to solve the structural instability problem of polyunsaturated fatty acids, pinolenic acid of P. koraiensis seed oil was effectively isolated and purified by the integrated strategy of ethyl esterification followed by urea inclusion for the first time. Under the optimal conditions after the Box-Benhnken Design experimental, ethyl pinolenate with high purity 94.95% could be obtained, and the average content of PNAEE can still reach 86.18%. Then ethyl pinolenate was characterized by Gas chromatography-mass spectrometry, Fourier transform infrared, and Nuclear magnetic resonance spectra, results showed that ethyl pinolenate was successfully prepared. In addition, the hypolipidemic activity of ethyl pinolenate had been tested in vivo and showed that ethyl pinolenate had obvious hypolipidemic activity. The new strategy for high purity ethyl pinolenate production from P. koraiensis seed oil possesses great potential in food healthy field in the future.

Curcuminoid Chalcones: Synthesis, Stability, and New Neuroprotective and Sonosensitising Activities.

The primary purpose of this work was to design and obtain a series of curcuminoid chalcone-NSAID hybrid derivatives. The ester-type hybrid compounds with ibuprofen (i), ketoprofen (ii), and naproxen (iii) were obtained in two ways, using the Claisen-Schmidt reaction and the Steglich esterification reaction. The designed molecules were successfully synthesised, and FT-IR, MS, and NMR spectroscopy confirmed their structures. Moreover, the cytotoxic effect of the sonodynamic therapy and the anti-inflammatory, antioxidant, and anticholinergic properties of some curcuminoid chalcones and curcuminoid chalcones hybrids were evaluated. The curcuminoid chalcone derivatives showed promising neuroprotective activity as sonosensitisers for sonodynamic therapy in the studied cell lines. Additionally, the stability of the ester-type hybrid compounds with promising activity was determined. The RP-HPLC method was used to observe the degradation of the tested compounds. Studies have shown that structural isomers of ester-type hybrid compounds (3ai, 3bi) are characterised by a similar susceptibility to degradation factors, i.e., they are extremely unstable in alkaline environments, very unstable in acidic environments, unstable in neutral environments, practically stable in oxidising environments, and photolabile in solutions and in the solid phase. These compounds maintain adequate stability in environment at pH 1.2 and 6.8, which may make them good candidates for developing formulations for oral administration.

25.24%-Efficiency FACsPbI3 Perovskite Solar Cells Enabled by Intermolecular Esterification Reaction of DL-Carnitine Hydrochloride.

Judicious tailoring of the interface between the SnO2 electron-transport layer and the perovskite buried surface plays a pivotal role in obtaining highly efficient and stable perovskite solar cells (PSCs). Herein, a DL-carnitine hydrochloride (DL) is incorporated into the perovskite/SnO2 interface to suppress the defect-states density. A DL-dimer is obtained at the interface by an intermolecular esterification reaction. For the SnO2 film, the Cl- in the DL-dimer can passivate oxygen vacancies (VO ) through electrostatic coupling, while the N in the DL-dimer can coordinate with the Sn4+ to passivate Sn-related defects. For the perovskite film, the DL-dimer can passivate FA+ defects via hydrogen bonding and Pb-related defects more efficiently than the DL monomer. Upon DL-dimer modification, the interfacial defects are effectively passivated and the quality of the resultant perovskite film is improved. As a result, the DL-treated device achieves a gratifying open-circuit voltage (VOC ) of 1.20 V and a champion power conversion efficiency (PCE) of 25.24%, which is a record value among all the reported FACsPbI3 PSCs to date. In addition, the unencapsulated devices exhibit a charming stability, sustaining 99.20% and 90.00% of their initial PCEs after aging in air for 1200 h and continuously operating at the maximum power point tracking for 500 h, respectively.

Study on Synthesizing Isobornyl Acetate/Isoborneol from Camphene Using α-Hydroxyl Carboxylic Acid Composite Catalyst.

This study examined the preparation of isobornyl acetate/isoborneol from camphene using an α-hydroxyl carboxylic acid (HCA) composite catalyst. Through the study of the influencing factors, it was found that HCA and boric acid exhibited significant synergistic catalysis. Under optimal conditions, when tartaric acid-boric acid was used as the catalyst, the conversion of camphene and the gas chromatography (GC) content and selectivity of isobornyl acetate were 92.9%, 88.5%, and 95.3%, respectively. With the increase in the ratio of water to acetic acid, the GC content and selectivity of isobornol in the product increased, but the conversion of camphene decreased. The yield of isobornol was increased by adding ethyl acetate or titanium sulfate/zirconium sulfate to form a ternary composite catalyst. When a ternary complex of titanium sulfate, tartaric acid, and boric acid was used as the catalyst, the GC content of isobornol in the product reached 55.6%. Under solvent-free conditions, mandelic acid-boric acid could catalyze the hydration reaction of camphene, the GC content of isoborneol in the product reached 26.1%, and the selectivity of isoborneol was 55.9%. The HCA-boric acid composite catalyst can use aqueous acetic acid as a raw material, which is also beneficial for the reuse of the catalyst.

Theoretical and Experimental Insights of Benzimidazole Catalyzed by the Epoxy-Acrylic Acid Reaction.

This study focuses on the experimental and molecular-level investigation of epoxy acrylate formation. Epoxy acrylate vinyl ester resin was prepared by a reaction of diglycidyl ether of bisphenol-A-based epoxy resin and acrylic acid, using benzimidazole as a catalyst. It was confirmed that benzimidazole can effectively catalyze this reaction. FTIR analysis of the product revealed a simple addition esterification reaction between the epoxide group and carboxylic group of acrylic acid excluding the side reactions (e.g., etherification). DFT computational studies were performed to theoretically explore the insights of reaction mechanisms. The calculations revealed that the benzimidazole-catalyzed reaction dominates the uncatalyzed reaction. A comparison of calculated activation energies showed that concerted mechanisms are less significant in such reactions owing to their high activation barriers.

The Effects of Catabolism Relationships of Leucine and Isoleucine with BAT2 Gene of Saccharomyces cerevisiae on High Alcohols and Esters.

This study sought to provide a theoretical basis for effectively controlling the content of higher alcohols and esters in fermented foods. In this work, isoleucine (Ile) or leucine (Leu) at high levels was used as the sole nitrogen source for a BAT2 mutant and its parental Saccharomyces. cerevisiae 38 to investigate the effects of the addition of amounts of Ile or Leu and BAT2 on the aroma components in the flavor profile using gas chromatography mass spectrometer (GC-MS). The results showed that 2-methyl-butyraldehyde, 2-methyl-1-butanol, and 2-methylbutyl-acetate were the products positively correlated with the Ile addition amount. In addition, 3-methyl-butyraldehyde, 3-methyl-1-butanol, and 3-methylbutyl-acetate were the products positively correlated with Leu addition amount. BAT2 deletion resulted in a significant decline in the yields of 2-methyl-butyraldehyde, 3-methyl-butyraldehyde,2-methyl-1-butanol, and 3-methyl-1-butanol, but also an increase in the yields of 2-methylbutyl-acetate and 3-methylbutyl-acetate. We speculated that BAT2 regulated the front and end of this metabolite chain in a feedback manner. Improved metabolic chain analyses, including the simulated energy metabolism of Ile or Leu, indicated that reducing the added amount of branched-chain amino acids, BAT mutation, and eliminating the role of energy cofactors such as NADH/NAD+ were three important ways to control the content of high alcohols and esters in fermented foods.

Fully Biobased Adhesive from Glucose and Citric Acid for Plywood with High Performance.

Biomass-based adhesives have attracted much attention due to their eco-friendly, sustainable characteristics compared to formaldehyde-based adhesives; however, their low bonding strength and water resistance restrict their application. Thus, developing a high-performance biomass-based adhesive with excellent bonding strength and water resistance is necessary. In this work, a fully biomass-based citric acid-glucose (CAG) adhesive was produced by the esterification reaction of glucose and citric acid, which was validated by Fourier transform infrared (FT-IR), 13C nuclear magnetic resonance (13C NMR), and liquid chromatography-mass spectrometry (LC-MS). Furthermore, the properties of the CAG adhesive were tuned considering the effects of reaction time and molar ratio of citric acid/glucose (CA/G). It was revealed that increasing the molar ratio of CA/G is more advantageous to improve the shear strength and water resistance of plywood than the reaction time. The dry and wet strengths of plywood bonded by the CAG adhesive can reach the standard requirement (≥0.7 MPa) when the molar ratios of CA/G were more than 0.6 and the reaction time was 1 h. These results were better than those bonded by the urea-formaldehyde (UF) resin. Therefore, this green adhesive shows great potential to replace the existing industrial UF resin adhesives.

Synthesis and physicochemical evaluation of octenylsuccinated kappa-carrageenan: Conventional versus microwave heating.

This research reported on the synthesis and the evaluation of new octenyl succinate (OS) kappa-carrageenan (KC) esterified derivatives (KC-OS). Two derivatives were synthesized using microwave (KC-OSMM) and conventional heating (KC-OSCM). The FT-IR and 1H NMR demonstrated the KC-OS esters formation with a higher degree of substitution for KC-OSMM (0.85) than KC-OSCM (0.62). The SEM testing showed the non-deteriorated morphology of KC after modification. The amphiphilic properties and surface activity of KC-OSs investigated by the conductivity method confirmed the formation of self-assembled aggregates beyond a critical aggregation concentration of 0.08% for KC-OSMM and 0.12% for KC-OSCM. Stable oil-in-water emulsions were formulated based on KC-OSs at the concentrations of 0.75% and 1%. Lower globule sizes were observed for KC-OSMM emulsions at 0.75% (12.30 µm) and 1% (08.86 µm), compared to KC-OSCM at 0.75% (32.75 µm) and 1% (19.6 µm). All results demonstrated that microwave synthesis resulted in obtaining novel derivatives with superior properties.

High-performance olfactory receptor-derived peptide sensor for trimethylamine detection based on Steglich esterification reaction and native chemical ligation connection.

Trimethylamine (TMA) commonly exists in daily life and is harmful to human health, therefore the convenient and sensitive monitoring of TMA is highly desired. In this study, we developed a method to fabricate a high-performance TMA sensor by chemically conjugating olfactory receptor-derived peptides (ORPs) to single-walled carbon nanotubes (SWCNTs) on interdigital electrodes. First, the SWCNTs were modified with thioester by Steglich esterification reaction. Next, the ORPs with a cysteine residue at the N-terminus were connected to the thioester by native chemical ligation and modified to the surface of the SWCNTs. The chemical connection method enabled more effective loading of ORPs to the SWCNTs compared to the previously reported physical connection method. Using this approach, the ORPs-SWCNTs sensor for gaseous TMA was fabricated and enabled detection of TMA with a concentration as low as 0.01 parts per trillion, which was three orders of magnitude lower than the reported lowest detection limit up to date. Furthermore, we tested the performance of the ORP-sensor with vaporized TMA and TMA generated from various spoiled food, and the sensor exhibited excellent sensitivity, selectivity, and stability for TMA detection. The results demonstrated the effectiveness of the proposed chemical connection method for the fabrication of ORP-sensor and the great potential of using these sensors for applications in environmental safety, food quality evaluation, and healthcare.

Dyeing Property Improvement of Madder with Polycarboxylic Acid for Cotton.

Cotton fabrics were dyed with the madder and compounds of citric acid (CA) and dicarboxylic acids [tartaric acid (TTA), malic acid (MLA), succinic acid (SUA)] as cross-linking agents and sodium hypophosphite (SHP) as the catalyst. The molecular structures and crystal structures of the dyed cotton fabrics were analyzed using Fourier-transform infrared spectroscopy (FTIR) and X-ray diffractometry (XRD), respectively. The results showed that the polycarboxylic acids esterified with the hydroxyl groups in the dye and cellulose, respectively, and the reaction mainly occurred in the amorphous region of the cotton fabric. Compared with the direct dyed cotton fabric, the surface color depth (K/S) values of the CA, CA+TTA, CA+MLA, CA+SUA cross-linked dyed cotton fabrics increased by approximately 160%, 190%, 240%, 270%, respectively. The CA+SUA cross-linked dyed cotton fabric achieved the biggest K/S value due to the elimination of the negative effect by α-hydroxyl in TTA and MLA on esterification reaction, and the cross-linked dyed cotton fabrics had great levelness property. The washing and rubbing fastness of the cross-linked cotton fabrics were above four levels. The light resistance stability and the antibacterial property of the cross-linked dyed cotton fabrics was obviously improved. The sum of warp and weft wrinkle recovery angle (WRA) of the CA+SUA cross-linked dyed cotton fabric was 55° higher than that of raw cotton fabric, and its average UV transmittance for UVA was less than 5% and its UPF value was 50+, showing a great anti-wrinkle and anti-ultraviolet properties.

Comparative Study on Different Modified Preparation Methods of Cellulose Nanocrystalline.

Different modification process routes are used to improve the modified cellulose nanocrystalline (MCNC) with higher fatty acid by esterification reaction and graft polymerization to obtain certain hydrophobic properties. Two preparation methods, product structure and surface activity, are compared and explored. Experimental results show that the modified product is still at the nanometer level and basically retains the crystal structure of the raw cellulose nanocrystalline (CNC). The energy consumption of the two preparation methods is low; however, the esterification method with co-reactant requires short reaction time, and the degree of substitution of the product is high. The modified product prepared by grafting polymerization method has a high HLB value and amphiphilicity, which can effectively reduce the surface tension of water. Therefore, it can be used as a green and environmentally friendly surface-active substance.

Synthesis and drug delivery properties of Ibuprofen-Cellulose nanofibril system.

The Ibuprofen-Cellulose nanofibril (IBU-CNF) drug delivery system was prepared by esterification of Ibuprofen (IBU) and cellulose nanofibril (CNF) with isopropyl acetate as the solvent and sulfuric acid as the catalyst. The results showed that IBU was successfully grafted on to the CNF molecular chain and the crystal structure of CNF did not change. Moreover, the natural three-dimensional network structure was maintained to a large extent. The maximum drug loading of IBU-CNF was 151.38 mg/g. In vitro drug release showed that IBU-CNF was pH-responsive and could be released continuously over 24 h. The cumulative release rate was approximately 90% under alkaline conditions but was low under acidic conditions. UV-visible spectra revealed that IBU retained its chemical activity after in vitro release.

Lipase activation by molecular bioimprinting: The role of interactions between fatty acids and enzyme active site.

Bioimprinting is an easy, sustainable and low-cost technique that promotes a printing of potential substrates on enzyme structure, inducing a more selective and stable conformation. Bioimprinting promotes conformational changes in enzymes, resulting in better catalytic performance. In this work, the effect of bioimprinting of Burkholderia cepacia lipase (BCL) and porcine pancreatic extracts (PPE) with four different fatty acids (lauric acid (C12:0), myristic acid (C14:0), palmitic acid (C16:0), and stearic acid (C18:0)) was investigated. The results demonstrated that the better bioimprinting effect was in BCL with lauric acid in esterification reaction, promoting BCL activation in which relative enzyme activity was 70 times greater than nonimprinted BCL. Bioimprinting results were influenced by the carbon chain length of fatty acids imprinted in the BCL, in which the effects were weaker with the chain increase. Molecular docking was performed to better understand the bioimprinting method. The results of these simulations showed that indeed all fatty acids were imprinted in the active site of BCL. However, lauric acid presented the highest imprinting preference in the active site of BCL, resulting in the highest relative activity. Furthermore, Fourier transform infrared (FTIR) analysis confirmed important variations in secondary structure of bioimprinting BCL with lauric acid, in which there was a reduction in the α-helix content and an increase in the ß-sheet content that facilitated substrate access to the active site of BCL and led higher rigidity, resulting in high activity. Bioimprinted BCL with lauric acid showed excellent operational stability in esterification reaction, maintaining its original relative activity after five successive cycles. Thus, the results show that bioimprinting of BCL with lauric acid is a successful strategy due to its high catalytic activity and reusability.

Functionalized phosphorylated cellulose microspheres: Design, characterization and ciprofloxacin loading and releasing properties.

In this work, functionalized phosphorylated cellulose microspheres (CMP) were designed as a carrier for the ciprofloxacin (CIP) drug delivery system. The CMP has been developed from cellulose microspheres (CM) and phosphoric acid via an esterification reaction. CIP, an antibiotic drug as a model, was loaded onto CIP via hydrogen bonds and electrostatic interactions. A series of test results showed that the CIP was successfully incorporated and released from the prepared CMP without the loss of structural integrity or changing its functionality. The release kinetics and mechanism suggest that CIP release follows first-order kinetics and non-Fickian diffusion mechanism. The cytotoxicity behavior of CMP enables the material as a suitable vehicle for the safe release of CIP. The CIP loaded microspheres exhibited a significant antibacterial effect due to the CIP release and diffusion from the microspheres. This study provides insight into the design of suitable cellulose microspheres for CIP delivery.

Elucidating esterification reaction during deposition of cutin monomers from classical molecular dynamics simulations.

The structural behavior of some cutin monomers, when deposited on mica support, was extensively investigated by our research group. However, other events, such as esterification reaction (ER), are still a way to explore. In this paper, we explore possible ER that could occur when these monomers adsorb on support. Although classical molecular dynamics simulations are not able to capture reactive effects, here, we show that they become valuable strategies to analyze the initial structural configurations to predict the most favorable reaction routes. Thus, when depositing aleuritic acid (ALE), it is observed that the loss of capacity to form self-assembled (SA) systems favors different routes to occur ER. In pure ALE bilayers systems, an ER is given exclusively through the -COOH and primary -OH groups. In pure ALE monolayers systems, the ER does not happen when the system is self-assembled. However, for disorganized systems, it is able to occur by two possible routes: -COOH and primary -OH (route 1) and -COOH and secondary -OH (route 2). When palmitic acid (PAL) is added in small quantities, ALE SAMs can now form an ER. In this case, ER occurs mostly through the -COOH and secondary -OH groups. However, when the presence of PAL is dominant, ER can occur with either of both possibilities, that is, routes 1 and 2. Graphical abstract.

4-Aminoquinoline-ferrocene Hybrids as Potential Antimalarials.

BACKGROUND: Malaria is a deadly disease. It is mostly treated using 4- aminoquinoline derivatives such as chloroquine etc. because it is well-tolerated, displays low toxicity, and after administration, it is rapidly absorbed. The combination of 4-aminoquinoline with other classes of antimalarial drugs has been reported to be an effective approach for the treatment of malaria. Furthermore, some patents reported hybrids 4-aminoquinolines containing ferrocene moiety with potent antimalarial activity. OBJECTIVE: The objective of the current study is to prepare 4-aminoquinoline-ferrocene hybrids via esterification and amidation reactions. The compounds were characterized via FTIR, LC-MS and NMR spectroscopy. In vitro screening against chloroquine-sensitive P. falciparum parasite (NF54) at concentrations (1 µM and 5 µM) and an inhibitory concentration (full dose-response) was studied. METHODS: The compounds were prepared via known reactions and monitored by Thin Layer Chromatography. The compounds were purified by column chromatography and characterized using FTIR, NMR and MS. In vitro antiplasmodial evaluation was performed against asexual parasite and chloroquine was used as a reference drug. RESULTS: The percentage inhibition effects of the hybrid compounds were in a range of 97.9-102% at 5 µM and 36-96% at 1 µM. Furthermore, the IC50 values of the compounds were in the range of 0.7-1.6 µM when compared to the parent drug, 4-ferrocenylketobutanoic acid. CONCLUSION: The hybrid compounds displayed significant antimalarial activity when compared to the parent drug. However, they were not as effective as chloroquine on the drug-sensitive parasite. The findings revealed that 4-aminoquinolines and ferrocene are potential scaffolds for developing potent antimalarials.

Stable Silicon Anode for Lithium-Ion Batteries through Covalent Bond Formation with a Binder via Esterification.

Silicon (Si) is considered to be one of the most promising anode candidates for next-generation lithium-ion batteries because of its high theoretical specific capacity and low discharge potential. However, its poor cyclability, caused by tremendous volume change during cycling, prevents commercial use of the Si anode. Herein, we demonstrate a high-performance Si anode produced via covalent bond formation between a commercially available Si nanopowder and a linear polymeric binder through an esterification reaction. For efficient ester bonding, polyacrylic acid, composed of -COOH groups, is selected as the binder, Si is treated with piranha solution to produce abundant -OH groups on its surface, and sodium hypophosphite is employed as a catalyst. The as-fabricated electrode exhibits excellent high rate capability and long cycle stability, delivering a high capacity of 1500 mA h g-1 after 500 cycles at a high current density of 1000 mA g-1 by effectively restraining the susceptible sliding of the binder, stabilizing the solid electrolyte interface layer, preventing the electrode delamination, and suppressing the Si aggregation. Furthermore, a full cell is fabricated with as-fabricated Si as an anode and commercially available LiNi0.6Mn0.2Co0.2O2 as a cathode, and its electrochemical properties are investigated for the possibility of practical use.

Polymer-Bound Triphenylphosphine and 4,4'-Dinitroazobenzene as a Coupling Reagents for Chromatography-Free Esterification Reaction.

AIM AND OBJECTIVE: Sustainable production of fine chemicals both in industries and pharmaceuticals heavily depends on the application of solid-phase synthesis route coupled with microwave technologies due to their environmentally benign nature. In this report, a microwave-assisted esterification reaction using polymer-bound triphenylphosphine and 4,4'-dinitroazobenzene reagent system was investigated. MATERIALS AND METHODS: The solvents were obtained from Merck India. Polymer-bound triphenylphosphine (~3 mmol triphenylphosphine moiety/g) was acquired from Sigma-Aldrich. The progress of the reaction was observed by thin-layer chromatography. All the reactions were performed in Milestones StartSYNTH microwave. The NMR spectra were recorded on Bruker Avance III 300, 400, and 500 MHz FT NMR Spectrometers. Using azo compound and polymer-bound triphenyl phosphine as a coupling reagent, esterification of different carboxylic acids with alcohols was performed under microwave irradiation. RESULTS: Esterification of benzoic acid with 1-propanol under microwave irradiation gave a high yield of 92% propyl benzoate in 60 minutes only. Isolation of the ester products was relatively simple as both the byproducts polymer-bound triphenylphosphine oxide and hydrazine could be removed by simple filtration. The rates of reactions were found to be directly proportional to the pKa of the benzoic acids. CONCLUSION: 4,4'-Dinitroazobenzene was introduced as a novel coupling reagent, in conjugation with polymer-bound triphenylphosphine, for esterification reactions under microwave irradiation. The low moisture sensitivity of the reaction system, easy separation of the byproducts, and column chromatographyfree isolation of esters help our methods with application significance, particularly from the 'Sustainable Chemistry' perspective.