A novel, electrochemical 3-component reaction for the synthesis of alkyl alkenesulfonates from cinnamic acids, SO2, and alkyl alcohols is reported. This metal-free process employs inexpensive and readily available graphite electrodes in combination with easy-to-use stock solutions of SO2 and enables a straightforward construction of the styrene sulfonate scaffold via a decarboxylative transformation. Mechanistic studies indicate a pseudo-Kolbe type reaction.
View Article and Find Full Text PDFHematopoietic stem cells (HSCs) are defined by their capacity to regenerate all main components of the peripheral blood, but individual HSCs exhibit a range of preferences for generating downstream cell types. Their propensities are thought to be epigenetically encoded, but few differential regulatory mechanisms have been identified. In this work, we explored the role of the DNA methyltransferase 3A (DNMT3A) in the megakaryocyte-biased HSC population, which is thought to reside at the top of the hematopoietic hierarchy.
View Article and Find Full Text PDFHaematopoietic stem cells maintain blood production throughout life. Although extensively characterized using the laboratory mouse, little is known about clonal selection and population dynamics of the haematopoietic stem cell pool during murine ageing. We isolated stem cells and progenitors from young and old mice, identifying 221,890 somatic mutations genome-wide in 1,845 single-cell-derived colonies.
View Article and Find Full Text PDFAn electrochemical one-pot synthesis of enaminyl sulfonate esters was established, featuring a quasidivided cell under constant current conditions. The multicomponent reaction utilizes simple and readily available alkylamines and an easy-to-use stock solution of SO and alcohols. Omission of additional supporting electrolyte through in-situ-generated monoalkylsulfite facilitates the downstream processing.
View Article and Find Full Text PDFMultifunctional ortho-quinones are required for the formation of thiol-catechol-connectivities (TCC) but can be delicate to handle. We present the electrochemical oxidation of the dipeptide DiDOPA, achieving up to 92 % conversion efficiency of the catechols to ortho-quinones. Graphite and stainless steel could be employed as cost-efficient electrodes.
View Article and Find Full Text PDFA sustainable, general and scalable electrochemical protocol for direct access to 3-(acylamidoalkyl)-2,1-benzisoxazoles by cathodic reduction of widely accessible nitro arenes is established. The method is characterised by a simple undivided set-up under constant current conditions, inexpensive and reusable carbon-based electrodes, and environmentally benign reaction conditions. The versatility of the developed protocol is demonstrated on 39 highly diverse examples with up to 81% yield.
View Article and Find Full Text PDFA novel polycyclic naphthalenone motif was obtained by electrochemical synthesis starting from naphthols. The process is solvent controlled, and the highly diastereoselective cyclization is due to a solvent cage. The direct, anodic dehydrogenative sp-coupling was carried out by flow electrolysis.
View Article and Find Full Text PDFAn electrochemical desulfurization of 2-mercapto-imidazoles to the corresponding imidazole is established. This novel anodic transformation is bromide-mediated and easy to conduct in the simplest electrochemical setup, consisting of an undivided cell, carbon electrodes, and constant current electrolysis. The method proved successful in 14 diverse examples of imidazoles and triazoles with up to a 97% yield.
View Article and Find Full Text PDFWe report a scalable hydrogenation method for nitriles based on cost-effective materials in a very simple two-electrode setup under galvanostatic conditions. All components are commercially and readily available. The method is very easy to conduct and applicable to a variety of nitrile substrates, leading exclusively to primary amine products in yields of up to 89% using an easy work-up protocol.
View Article and Find Full Text PDFA pilot scale plant at Technology Readiness Level (TRL) 6 comprising an electrochemical ex-cell continuous production of sodium peroxodicarbonate and a thermal depolymerization plug flow reactor for kraft lignin conversion is established. Due to the labile nature of the "green" oxidizer peroxodicarbonate, special attention must be paid to the production parameters in order to optimize its use. A simplified design model describing steady-state and transient operations is formulated and finally validated against experimental data from the electrolysis setup.
View Article and Find Full Text PDFIminophosphoranes are commonly used reagents in organic synthesis and are, therefore, of great interest. An efficient and sustainable iodide-mediated electrochemical synthesis of -sulfonyl iminophosphoranes from readily available phosphines and sulfonamides is reported. This method features low amounts of supporting electrolytes, inexpensive electrode materials, a simple galvanostatic setup, and high conversion rates.
View Article and Find Full Text PDFThe direct anodic conversion of alkali carbonates in aqueous media provides access to peroxodicarbonate, which is a safe to use and green oxidizer. Although first reports date back around 150 years, its low concentrations and limited thermal stability have consigned this reagent to oblivion. Boron-doped diamond anodes, novel electrolyser concepts for heat dissipation, and the mixed cation trick allow record breaking peroxodicarbonate concentrations >900 mM.
View Article and Find Full Text PDFThe electrochemical reduction of nitroarenes allows direct access to manifold nitrogen containing heterocycles. This work reports the simple and direct electro-organic synthesis of 18 different examples of 2,4-4-hydroxy-1,4-benzoxazin-3-ones in up to 81% yield. The scalability of the method was demonstrated on a gram-scale.
View Article and Find Full Text PDFA new and practical method for the thermal degradation of technically relevant bio-based lignin is presented. By heating a solution of lignin in highly concentrated caustic potash, vanillic acid is almost exclusively obtained in yields up to 10.6 wt %.
View Article and Find Full Text PDFBackground: The optimal timing of vaccination with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines after cellular therapy is incompletely understood. The objectives of this study are to determine whether humoral and cellular responses after SARS-CoV-2 vaccination differ if initiated <4 months versus 4-12 months after cellular therapy.
Methods: We conducted a multicenter, prospective, observational study at 30 cancer centers in the United States.
We present an analysis of a set of molecular, electrical, and electronic properties for a large number of the cations of quaternary ammonium salts usually employed as supporting electrolytes in cathodic reduction reactions. The goal of the present study is to define a measure for the quality of a supporting electrolyte in terms of the yield of the reaction considered. We performed a principal component analysis using the normalized values of the properties in order to lower the number of relevant reaction coordinates and find that the integral variance of 13 properties can well be represented by three principal components.
View Article and Find Full Text PDFA novel synthesis of sitagliptin based on a redox-active ester derived from the chiral pool is reported. The key step is an electrochemical nickel-catalyzed sp-sp cross-coupling reaction using inexpensive nickel foam in an undivided cell. It was successfully applied to 21 examples in up to 88% yield.
View Article and Find Full Text PDFAn intramolecular electrochemical dehydration reaction of dicarboxylic acids to their cyclic anhydrides is presented. This electrolysis allows dicarboxylic acids as naturally abundant, inexpensive, safe, and readily available starting materials to be transformed into carboxylic anhydrides under mild reaction conditions. No conventional dehydration reagent is required.
View Article and Find Full Text PDFA dynamic thermodynamic resolution method for converting (/)-BINOL (1,1'-binaphthyl-2,2'-diol) into ()-BINOL in 100% theoretical yield is reported. This technique involves mixing (/)-BINOL with -benzyl cinchonidinium bromide (1 equiv) and a [Cu(tmeda)(μ-OH)]Br (2.5 mol %) redox catalyst in acetonitrile.
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