Study on Autocatalytic Decomposition of Dimethyl Sulfoxide (DMSO)

Microfluidic capillary electrophoresis - mass spectrometry for rapid charge-variant and glycoform assessment of monoclonal antibody biosimilar candidates

Early-stage cell line screening is a vital step in developing biosimilars of therapeutic monoclonal antibodies (mAbs). While the quality of the manufactured antibodies is commonly assessed by charge-based separation methods employing UV absorbance detection, these methods lack the ability to identify resolved mAb variants. We evaluated the performance of microfluidic capillary electrophoresis coupled to mass spectrometry (MCE-MS) as a rapid tool for profiling mAb biosimilar candidates from clonal cell lines. A representative originator sample was used to develop the MCE-MS method. The addition of dimethylsulfoxide (DMSO) to the background electrolyte yielded up to 60-fold enhancement of the protein MS signal. The resulting electropherograms consistently provided resolution of mAb charge variants within 10 min. Deconvoluted mass spectra facilitated the identification of basic variants such as C-terminal lysine and proline amidation, while the acidic variants could be assigned to deamidated forms. The MCE-MS method also allowed the identification of 18 different glycoforms in biosimilar samples. To mimic early-stage cell line selection, samples from five clonal cell lines that all expressed the same biosimilar candidate mAb were compared to their originator mAb. Based on the similarity observed in charge variants and glycoform profiles acquired by MCE-MS, the most promising candidate could be selected. The MCE-MS method demonstrated good overall reproducibility, as confirmed by a transferability study involving two separate laboratories. This study highlights the efficacy of the MCE-MS method for rapid proteoform screening of clonal cell line samples, underscoring its potential significance as an analytical tool in biosimilar process development.

Controlling Tin Halide Perovskite Oxidation Dynamics in Solution for Perovskite Optoelectronic Devices

As a leading contender to replace lead halide perovskites, tin-based perovskites have demonstrated ever increasing performance in solar cells and light-emitting diodes (LEDs). They tend to be processed with dimethyl sulfoxide (DMSO) solvent, which has been identified as a major contributor to the Sn(II) oxidation during film fabrication, posing a challenge to the further improvement of Sn-based perovskites. Herein, we use NMR spectroscopy to investigate the kinetics of the oxidation of SnI2, revealing that autoamplification takes place, accelerating the oxidation as the reaction progresses. We propose a mechanism consistent with these observations involving water participation and HI generation. Building upon these insights, we have developed low-temperature Sn-based perovskite LEDs (PeLEDs) processed at 60 °C, achieving enhanced external quantum efficiencies (EQEs). Our research underscores the substantial potential of low-temperature DMSO solvent processes and DMSO-free solvent systems for fabricating oxidation-free Sn-based perovskites, shaping the future direction in processing Sn-containing perovskite materials and optoelectronic devices.

Modular synthesis of pyrrole-fused heterocycles via glucose-mediated nitro-reductive cyclization

A novel biomass-derived glucose-mediated one-pot multicomponent nitro-reductive cyclization method is presented for the direct synthesis of diverse pyrrole-fused heterocycles. The process involves two-component reactions of alkyl (NH)-pyrrole-2-carboxylates and 2-fluoronitroarenes, yielding pyrrolo[1,2-a]quinoxalin-4(5H)-ones, as well as three-component reactions utilizing (NH)-pyrroles, nitroarenes, and DMSO as carbon sources, resulting in various pyrrolo[1,2-a]quinoxaline derivatives. High yields were achieved with broad substrate scope and gram-scale synthesis capability, including pharmaceuticals featuring pyrroloquinoxaline scaffolds. The method's key innovation lies in enabling three or four reactions in a single-pot setup, previously unexplored in pyrrole chemistry. The simplicity of nitro group reduction by biomass-derived glucose ensures practical safety during scale-up, while mechanistic insights from control experiments reveal a new paradigm in pyrrole chemistry. The tandem process demonstrates low PMI values and high step and atom economies, aligning well with green chemistry principles.

Umpolung Flow Chemistry for the Synthesis of a 3-Oxo-3H-spiro[benzofuran-2,4'-piperidine] Building Block

An efficient and scalable route to tert-butyl 3-oxo-3H-spiro[benzofuran-2,4'-piperidine]-1'-carboxylate, a central prochiral intermediate in the synthesis of SHP2 inhibitor GDC-1971 (migoprotafib), was achieved. Preparation of the title compound from readily available 2-fluorobenzaldehyde included formation of a modified Katritzky benzotriazole hemiaminal, which, upon deprotonation by n-butyllithium, participated in umpolung reactivity via 1,2-addition to tert-butyl 4-oxopiperidine-1-carboxylate (N-Boc-4-piperidone). Most notably, this reaction was developed as a robust plug-flow process that could be executed on multiple kilograms without the need for pilot-scale reaction vessels operating at low cryogenic temperatures. Treatment of the resulting tetrahedral intermediate with oxalic acid resulted in collapse to the corresponding 4-(2-fluorobenzoyl)-4-hydroxypiperidine, which was isolated as a solid via crystallization. The synthesis concluded with an optimized intramolecular SNAr reaction and final crystallization to generate tert-butyl 3-oxo-3H-spiro[benzofuran-2,4'-piperidine]-1'-carboxylate as a stable, high-quality intermediate suitable for further functionalization toward GDC-1971.

A novel sacrificial solvent method to synthesize self-supporting Co9S8/Ni3S2 heterostructure catalyst for efficient oxygen evolution reaction

Synthesizing catalysts for efficient oxygen evolution reaction (OER) with lower cost and simpler design is of significant importance to achieve sustainable hydrogen production. In this work, we propose a novel "sacrificial solvent method" for the first time. Dicobalt octacarbonyl (Co2(CO)8), dimethyl sulfoxide (DMSO), and Ni foam (NF) were used as the raw materials in the solvothermal process. DMSO played the role of both the sacrificial solvent and the sulfur source. Through the self-consumption of DMSO, we finally obtained the Co9S8/Ni3S2 heterostructure supported on the NF (Co9S8/Ni3S2@NF) in one step. The Co9S8/Ni3S2@NF catalyst exhibited excellent OER activity in alkaline environment, with an overpotential of only 264 mV at a current density of 20 mA cm-2, a low Tafel slope of 68.28 mV dec-1 and maintained its current density after 20 h of constant potential testing. This work introduces a new method for synthesizing metal sulfide catalysts using DMSO as a sacrificial solvent. It provides broader opportunities for the development of more efficient and sustainable catalysts for energy conversion and storage.

H2O2-Mediated Synthesis of a Quinazolin-4(3H)-one Scaffold: A Sustainable Approach

A quinazolin-4(3H)-one ring system is a privileged heterocyclic moiety with distinctive biological properties. From this perspective, the development of an efficient strategy for the synthesis of quinazolin-4(3H)-one has always been in demand for the synthetic chemistry community. In this report, we envisaged an efficient protocol for the synthesis of quinazolin-4(3H)-one using substituted 2-amino benzamide with dimethyl sulfoxide (DMSO) as a carbon source and H2O2 as an effective oxidant. Mechanistically, the reaction proceeds through the radical approach with DMSO as one carbon source. To further substantiate the synthetic claim, the synthetic protocol has been extended to the synthesis of the anti-endotoxic active compound 3-(2-carboxyphenyl)-4-(3H)-quinazolinone.

Characterization of an unanticipated indium-sulfur metallocycle complex

We have produced a novel indium-based metallocycle complex (In-MeSH), which we initially observed as an unanticipated side-product in metal-organic framework (MOF) syntheses. The serendipitously synthesized metallocycle forms via the acid-catalysed decomposition of dimethyl sulfoxide (DMSO) during solvothermal reactions in the presence of indium nitrate, dimethylformamide and nitric acid. A search through the Cambridge Structural Database revealed isostructural zinc, ruthenium and palladium metallocycle complexes formed by other routes. The ruthenium analogue is catalytically active and the In-MeSH structure similarly displays accessible open metal sites around the outside of the ring. Furthermore, this study also gives access to the relatively uncommon oxidation state of In(II), the targeted synthesis of which can be challenging. In(II) complexes have been reported as having potentially important applications in areas such as catalytic water splitting.

Carbon Dioxide Radical Anion by Photoinduced Equilibration between Formate Salts and [11C, 13C, 14C]CO2: Application to Carbon Isotope Radiolabeling

The need for carbon-labeled radiotracers is increasingly higher in drug discovery and development (carbon-14, β^-, t_1/2 = 5730 years) as well as in positron emission tomography (PET) for in vivo molecular imaging applications (carbon-11, β⁺, t_1/2 = 20.4 min). However, the structural diversity of radiotracers is still systematically driven by the narrow available labeled sources and methodologies. In this context, the emergence of carbon dioxide radical anion chemistry might set forth potential unexplored opportunities. Based on a dynamic isotopic equilibration between formate salts and [¹³C, ¹⁴C, ¹¹C]CO₂, C-labeled radical anion CO₂^•- could be accessed under extremely mild conditions within seconds. This methodology was successfully applied to hydrocarboxylation and dicarboxylation reactions in late-stage carbon isotope labeling of pharmaceutically relevant compounds. The relevance of the method in applied radiochemistry was showcased by the whole-body PET biodistribution profile of [¹¹C]oxaprozin in mice.

Synthesis of New Polyheterocyclic Pyrrolo[3,4-b]pyridin-5-ones via an Ugi-Zhu/Cascade/Click Strategy

A diversity-oriented synthesis (DOS) of two new polyheterocyclic compounds was performed via an Ugi-Zhu/cascade (N-acylation/aza Diels-Alder cycloaddition/decarboxylation/dehydration)/click strategy, both step-by-step to optimize all involved experimental stages, and in one pot manner to evaluate the scope and sustainability of this polyheterocyclic-focused synthetic strategy. In both ways, the yields were excellent, considering the high number of bonds formed with release of only one carbon dioxide and two molecules of water. The Ugi-Zhu reaction was carried out using the 4-formylbenzonitrile as orthogonal reagent, where the formyl group was first transformed into the pyrrolo[3,4-b]pyridin-5-one core, and then the remaining nitrile group was further converted into two different nitrogen-containing polyheterocycles, both via click-type cycloadditions. The first one used sodium azide to obtain the corresponding 5-substituted-1H-tetrazolyl-pyrrolo[3,4-b]pyridin-5-one, and the second one with dicyandiamide to synthesize the 2,4-diamino-1,3,5-triazine-pyrrolo[3,4-b]pyridin-5-one. Both synthesized compounds may be used for further in vitro and in silico studies because they contain more than two heterocyclic moieties of high interest in medicinal chemistry, as well as in optics due to their high π-conjugation.

Application of Self-Assembled Polyarylether Substrate in Flexible Organic Light-Emitting Diodes

The structure used in this study is as follows: substrate/PMMA/ZnS/Ag/MoO3/NPB/Alq3/LiF/Al. Here, PMMA serves as the surface flattening layer, ZnS/Ag/MoO3 as the anode, NPB as the hole injection layer, Alq3 as the emitting layer, LiF as the electron injection layer, and aluminum as the cathode. The properties of the devices with different substrates were investigated using P4 and glass, developed in the laboratory, as well as commercially available PET. After film formation, P4 creates holes on the surface. The light field distribution of the device was calculated at wavelengths of 480 nm, 550 nm, and 620 nm using optical simulation. It was found that this microstructure contributes to light extraction. The maximum brightness, external quantum efficiency, and current efficiency of the device at a P4 thickness of 2.6 μm were 72,500 cd/m², 1.69%, and 5.68 cd/A, respectively. However, the maximum brightness of the same structure with PET (130 μm) was 9500 cd/m². The microstructure of the P4 substrate was found to contribute to the excellent device performance through analysis of the AFM surface morphology, film resistance, and optical simulation results. The holes formed by the P4 substrate were created solely by spin-coating the material and then placing it on a heating plate to dry, without any special processing. To confirm the reproducibility of the naturally formed holes, devices were fabricated again with three different emitting layer thicknesses. The maximum brightness, external quantum efficiency, and current efficiency of the device at an Alq3 thickness of 55 nm were 93,400 cd/m², 1.7%, and 5.6 cd/A, respectively.

Intramolecular cyclization reactions of arylpropargyl amides of electron-deficient α,β-alkenyl carboxylates and related compounds

Intramolecular cyclization reactions of arylpropargyl amides of electron-deficient α,β-alkenyl carboxylates such as fumarates and ethenetricarboxylates were investigated. The reaction of the fumaramides with a base, Et₃N or DBU in xylenes at 140 °C under air gave benz[f]isoindoline derivatives in 21-63% yields. The benz[f]isoindolines may be produced via the formation of an allenic intermediate, intramolecular Diels-Alder reaction, proton transfer, and dehydrogenation by oxygen. The suitable bases and the product yields depend on the substituents on the benzene ring. On the other hand, the reaction of the amides of fumarate and ethenetricarboxylate by heating in DMSO gave aroyl-substituted pyrrolidine derivatives as major products, probably via addition of water under metal-free conditions. Furthermore, cyclization reactions of H and Me substituted alkyne derivatives were investigated for comparison. The selective formation of various types of products, such as ethyl 2-(1-benzyl-4-formyl-2-oxopyrrolidin-3-yl)acetate and diethyl 2-(1-benzyl-2-oxo-4-vinylidenepyrrolidin-3-yl)malonate, was found, depending upon the alkyne substituents and the reaction conditions. The reaction mechanisms have been discussed using density functional theory (DFT) calculations.

Efficiency Analysis of Fuel Cell Components with Ionic Poly-Arylether Composite Membrane

We use polyethylene glycol as an additive to explore how the hydrogen bonding of this additive changes the properties of SA8 blended sulfonated polyetheretherketone (SPEEK) composite films. We mixed a 5%wt polyethylene glycol solution into a 12.5%wt SA8 solution, and then prepared a film with a total weight of 40 g at a ratio of 1:99. The SA8 (PEG) solution was prepared and then mixed with 5%wt SPEEK solution, and a film-forming solution with a total weight of 8g in different mixing ratios was created. Polyethylene glycol (PEG) was mixed into the sulfonated polyarylether polymer SA8 to form physical cross-linking. Therefore, the sulfonated polyether ether ketone SPEEK was mixed in, and it exhibited good thermal stability and dimensional stability. However, there was some decrease in proton conductivity as the proportion of SPEEK increased. Although SPEEK mixed with sulfonated polymer reduces the proton conductivity, the physical cross-linking of PEG can improve the proton conductivity of the composite membrane, and adding SPEEK can not only solve the problem of the high sulfonation film swelling phenomenon, it can also improve the dimensional stability of the film through the hydrogen bonding force of PEG and obtain a composite film with excellent properties.

Reaction Optimization for Greener Chemistry with a Comprehensive Spreadsheet Tool

Green chemistry places an emphasis on safer chemicals, waste reduction, and efficiency. Processes should be optimized with green chemistry at the forefront of decision making, embedded into research at the earliest stage. To assist in this endeavor, we present a spreadsheet that can be used to interpret reaction kinetics via Variable Time Normalization Analysis (VTNA), understand solvent effects with linear solvation energy relationships (LSER), and calculate solvent greenness. With this information, new reaction conditions can be explored in silico, calculating product conversions and green chemistry metrics prior to experiments. The application of this tool was validated with literature case studies. Reaction performance was predicted and then confirmed experimentally for examples of aza-Michael addition, Michael addition, and an amidation. The combined analytical package presented herein permits a thorough examination of chemical reactions, so that the variables that control reaction chemistry can be understood, optimized, and made greener for research and education purposes.

Sporopollenin-inspired design and synthesis of robust polymeric materials

Sporopollenin is a mechanically robust and chemically inert biopolymer that constitutes the outer protective exine layer of plant spores and pollen grains. Recent investigation of the molecular structure of pine sporopollenin revealed unique monomeric units and inter-unit linkages distinct from other previously known biopolymers, which could be harnessed for new material design. Herein, we report the bioinspired synthesis of a series of sporopollenin analogues. This exercise confirms large portions of our previously proposed pine sporopollenin structural model, while the measured chemical, thermal, and mechanical properties of the synthetic sporopollenins constitute favorable attributes of a new kind of robust material. This study explores a new design framework of robust materials inspired by natural sporopollenins, and provides insights and reagents for future elucidation and engineering of sporopollenin biosynthesis in plants.

Terahertz-Wave Absorption Gas Sensing for Dimethyl Sulfoxide

Gas sensing for dimethyl sulfoxide (DMSO) based on rotational absorption spectroscopy is demonstrated in the 220–330 GHz frequency range using a robust electronic THz-wave spectrometer. DMSO is a flammable liquid commonly used as a solvent in the food and pharmaceutical industries, materials synthesis, and manufacturing. DMSO is a hazard to human health and the work environment; hence, remote gas sensing for DMSO environmental and process monitoring is desired. Absorption measurements were carried out for pure DMSO at 297 K and 0.4 Torr (53 Pa). DMSO was shown to have a unique rotational fingerprint with a series of repeating absorption bands. The frequencies of transitions observed in the present study were found to be in good agreement with spectral simulations carried out based on rotational parameters derived in prior work. Newly, intensities of the rotational absorption lines were experimentally observed and reported for DMSO in this study. Measured intensities for major absorption lines were found in very good agreement with relative line intensities estimated by quantum mechanical calculations. The sensor developed here exhibited a detection limit of 1.3 × 1015–2.6 × 1015 DMSO molecules/cm3 per meter of absorption path length, with the potential for greater sensitivity with signal-to-noise improvements. The study illustrates the potential of all electronic THz-wave systems for miniaturized remote gas sensors.

Ultrahigh Size Exclusion Selectivity for Carbon Dioxide from Nitrogen/Methane in an Ultramicroporous Metal-Organic Framework

Separations based on molecular size (molecular sieving) are a solution for environmental remediation. We have synthesized and characterized two new metal-organic frameworks (MOFs) (Zn₂M; M = Zn, Cd) with ultramicropores (<0.7 nm) suitable for molecular sieving. We explore the synthesis of these MOFs and the role that the DMSO/H₂O/DMF solvent mixture has on the crystallization process. We further explore the crystallographic data for the DMSO and methanol solvated structures at 273 and 100 K; this not only results in high-quality structural data but also allows us to better understand the structural features at temperatures around the gas adsorption experiments. Structurally, the main difference between the two MOFs is that the central metal in the trimetallic node can be changed from Zn to Cd and that results in a sub-Å change in the size of the pore aperture, but a stark change in the gas adsorption properties. The separation selectivity of the MOF when M = Zn is infinite given the pore aperture of the MOF can accommodate CO₂ while N₂ and/or CH₄ is excluded from entering the pore. Furthermore, due to the size exclusion behavior, the MOF has an adsorption selectivity of 4800:1 CO₂/N₂ and 5 × 10²⁸:1 CO₂/CH₄. When M = Cd, the pore aperture of the MOF increases slightly, allowing N₂ and CH₄ to enter the pore, resulting in a 27.5:1 and a 10.5:1 adsorption selectivity, respectively; this is akin to UiO-66, a MOF that is not able to function as a molecular sieve for these gases. The data delineate how subtle sub-Å changes to the pore aperture of a framework can drastically affect both the adsorption selectivity and separation selectivity.

Dehydration of fructose to 5-hydroxymethylfurfural over a mesoporous sulfonated high-crosslinked polymer in different solvents

SHCP was active and stable for dehydration of fructose to 5-HMF in DIO/H2O as H2O depressed oligomerization of 5-HMF.

Depolymerization of Technical-Grade Polyamide 66 and Polyurethane Materials through Hydrogenation

Chemical recycling provides a promising solution to utilize plastic waste. Here, a catalytic hydrogenative depolymerization of polyamide 66 (PA 66) and polyurethane (PU) was developed. The system employed Ru pincer complexes at high temperature (200 °C) in THF solution, and even technical-grade polymers could be hydrogenated with satisfactory yields under these conditions. A comparison of the system with some known heterogeneous catalysts as well as catalyst poisoning tests supported the homogeneity of the system. These results demonstrate the potential of chemical recycling to regain building blocks for polymers and will be interesting for the further development of polymer hydrogenation.

An expedient route to tricyanovinylindoles and indolylmaleimides from o-alkynylanilines utilising DMSO as a one-carbon synthon

A Pd(ii)/Cu(ii) catalysed domino synthesis of tricyanovinylindoles has been achieved using DMSO as a one-carbon synthon. The reaction proceeds via the construction of 2-aryl-3-formyl indole followed by sequential addition of malononitrile and a CN resulting in two C-C, one C[double bond, length as m-dash]C and one C-N bonds in the final product. Furthermore, post-synthetic modification results in the unprecedented formation of 4-cyano-3-indolylmaleimides. Photophysical studies of selected compounds show emission in the visible range.

Radical Chain Reduction via Carbon Dioxide Radical Anion (CO2•-)

We developed an effective method for reductive radical formation that utilizes the radical anion of carbon dioxide (CO₂^•-) as a powerful single electron reductant. Through a polarity matched hydrogen atom transfer (HAT) between an electrophilic radical and a formate salt, CO₂^•- formation occurs as a key element in a new radical chain reaction. Here, radical chain initiation can be performed through photochemical or thermal means, and we illustrate the ability of this approach to accomplish reductive activation of a range of substrate classes. Specifically, we employed this strategy in the intermolecular hydroarylation of unactivated alkenes with (hetero)aryl chlorides/bromides, radical deamination of arylammonium salts, aliphatic ketyl radical formation, and sulfonamide cleavage. We show that the reactivity of CO₂^•- with electron-poor olefins results in either single electron reduction or alkene hydrocarboxylation, where substrate reduction potentials can be utilized to predict reaction outcome.