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While chemistry exists in three dimensions, it is presented in two. This down-conversion results in a significant loss in information and often necessitates multiple images/figures to convey the complexity, intricacy, and beauty of a given structure. Currently, three-dimensional models are built to allow students to interact with molecules. However, model building for students is time-consuming, has the potential for error, and requires the purchase of a model kit. Outlined herein is a concise, straightforward method for incorporating interactive three-dimensional (i-3D) figures into teaching aids in PDF format. These figures can be generated from a variety of sources and allow for structures, molecular orbitals, unit cells and crystal lattices, as well as biopolymers to be presented in the same information-rich format as they are created. These images can be seen and interacted with by anyone reading the file in the standard PDF software (Adobe Reader). It is time for chemical education to take advantage of the digital age.

Die stereoselektive Bildung von 1,2‐cis‐glykosidischen Bindungen ist bislang sehr anspruchsvoll. Häufig wird diese 1,2‐cis‐Selektivität durch Fernpartizipation (remote participation) von C4‐ oder C6‐Estergruppen herbeigeführt. Hierbei wird davon ausgegangen, dass ein ionisches Schlüsselintermediat, das Glykosylkation, gebildet wird. Obwohl derartige Mechanismen bereits vor Jahrzehnten postuliert wurden, konnte die exakte Struktur dieses Intermediats aufgrund seiner Kurzlebigkeit bisher nicht aufgeklärt werden. In dieser Studie nutzen wir kryogene Schwingungsspektroskopie und quantenchemische Rechnungen, um die Strukturen dieser Glykosylkationen aufzuklären. Acetylgruppen an der C4‐Position führen zur selektiven Bildung von α‐Galaktosiden, indem eine kovalente Bindung zum anomeren Kohlenstoff gebildet wird. Überraschenderweise können auch Benzylgruppen die stereoselektive Bildung von 1,2‐cis‐glykosidischen Bindungen durch Fernpartizipation herbeiführen.

Intrinsically stretchable solid-state conductors can shed light on the realization of further biocompatible and reliable wearable electronics. However, their material composition should be optimized considering the compatibility of target stretchable platforms. In this paper, we report directly printable conductive elastomeric composites for intrinsically stretchable conductors. A pneumatic direct ink writing system is employed to deposit well-defined patterns. Polydimethylsiloxane (PDMS), Ag particles, and multi-walled carbon nanotubes were used as the elastomeric matrix, conductive fillers, and auxiliary fillers, respectively. Because there is a critical trade-off between the conductivity and stretchability depending on the concentration of conductive fillers, we optimize the Ag concentration to 77.5 wt% to fulfill these requirements. In particular, we introduce multi-solvent Ag composite inks to simultaneously deliver excellent printability and enhanced conductivity. We further investigated the electromechanical reliability of the encapsulated conductors undergoing cyclic strains, finding that they exhibited stable R/R O values over 50% strain.

Current drug production in batch cannot adapt rapidly to market demands,} evidenced by recent shortages in many markets globally of essential medicines. Flow chemistry is a valuable tool for on-demand production of active pharmaceutical ingredients (APIs). Here{,} we reveal a new concept to develop and produce APIs{,} where an automated synthesizer that works with discrete volumes of solutions is employed at the discovery stage to identify the optimal synthetic route and conditions before a commercially available continuous flow system is used for scale-up. This concept is illustrated by the synthesis of nifedipine and paracetamol{,} in short supply in Germany during the COVID-19 pandemic{, and the local anesthetic lidocaine.

Predicting the stereochemical outcome of chemical reactions is challenging in mechanistically ambiguous transformations. The stereoselectivity of glycosylation reactions is influenced by at least eleven factors across four chemical participants and temperature. A random forest algorithm was trained using a highly reproducible, concise dataset to accurately predict the stereoselective outcome of glycosylations. The steric and electronic contributions of all chemical reagents and solvents were quantified by quantum mechanical calculations. The trained model accurately predicts stereoselectivities for unseen nucleophiles, electrophiles, acid catalyst, and solvents across a wide temperature range (overall root mean square error 6.8%). All predictions were validated experimentally on a standardized microreactor platform. The model helped to identify novel ways to control glycosylation stereoselectivity and accurately predicts previously unknown means of stereocontrol. By quantifying the degree of influence of each variable, we begin to gain a better general understanding of the transformation, for example that environmental factors influence the stereoselectivity of glycosylations more than the coupling partners in this area of chemical space., A random forest algorithm, trained on a concise dataset and validated experimentally, accurately predicts the stereoselectivity of a complex organic coupling varying all reaction parameters as well as previously unknown mechanistic influences.

It has been reported that fragments produced by glycosidic bond breakage in mass spectrometry‐based experiments can retain a memory of their anomeric configuration, which has major implications for glycan sequencing. Herein, we use cryogenic vibrational spectroscopy and ion mobility‐mass spectrometry to study the structure of B‐type fragments of protected galactosides. Cationic fragments were generated from glycosyl donors carrying trichloroacetimidate or thioethyl leaving groups of different anomeric configuration. The obtained infrared signatures indicate that the investigated fragments exhibit an identical structure, which suggests that there is no anomeric memory in B‐type ions of fully protected monosaccharides., Do you remember? Some of the glycan fragments produced in mass spectrometers can retain a memory of their anomeric configuration. Herein, we use gas‐phase infrared spectroscopy to study the structure of B‐type fragments of protected galactosides. The infrared signatures indicate that the investigated fragments exhibit an identical structure.

While chemistry exists in three-dimensions, it is published in two. This down-conversion results in a significant loss in information and often necessitates multiple images/figures to convey the complexity, intricacy, and beauty of a given structure. Outlined herein is a concise, straightforward method for incorporating interactive three-dimensional (i-3D) figures into manuscript pdfs. These figures can be generated from a variety of sources and allow for structures, molecular orbitals, unit cells and crystal lattices, as well as biopolymers to be published in the same information rich format as they are created and studied on our computers. These images can be seen and interacted with by anyone reading the manuscript in the standard pdf software (Adobe Reader) – and to fully appreciate this article, please read it using Adobe Reader. It is time for chemistry publications to take advantage of the digital age.

A new and mild synthetic approach for the synthesis of N-arylsulfonamides under copper-catalyzed conditions at room temperature has been developed. The reaction employs various tert-butyl N-sulfonylcarbamates and diaryliodonium salts to avoid potential genotoxic impurities. A one-pot coupling/Boc-deprotection sequence is also reported to provide mono N-arylsulfonamides in good to excellent yields.

Reliable glycosylation reactions that allow for the stereo- and regioselective installation of glycosidic linkages are paramount to the chemical synthesis of glycan chains. The stereoselectivity of glycosylations is exceedingly difficult to control due to the reaction's high degree of sensitivity and its shifting, simultaneous mechanistic pathways that are controlled by variables of unknown degree of influence, dominance, or interdependency. An automated platform was devised to quickly, reproducibly, and systematically screen glycosylations and thereby address this fundamental problem. Thirteen variables were investigated in as isolated a manner as possible, to identify and quantify inherent preferences of electrophilic glycosylating agents (glycosyl donors) and nucleophiles (glycosyl acceptors). Ways to enhance, suppress, or even override these preferences using judicious environmental conditions were discovered. Glycosylations involving two specific partners can be tuned to produce either 11:1 selectivity of one stereoisomer or 9:1 of the other by merely changing the reaction conditions.

A mild and efficient synthesis of N-arylcarbamates was achieved by reacting azidoformates with boronic acids in the presence of 10 mol % of copper chloride catalyst. The reaction proceeds readily in an open flask at room temperature without additional base, ligand, or additive. Rapid access to urea analogues via a two-step one-pot procedure is enabled by reacting N-arylcarbamates with aluminum-amine complexes. In addition, among several boronic acid derivatives prepared, dimethylphenyl boronate was found to react rapidly in its reaction with benzyl azidoformate, invoking in situ generation of this species in the catalytic cycle.

An efficient method for the synthesis of ketones using organolithium and acid chlorides under continuous flow conditions has been developed. In contrast to standard batch chemistry, over-addition of the organolithium to the ketone for the formation of the undesired tertiary alcohol has been minimised representing a direct approach toward ketones.

A new and mild synthetic approach for the synthesis of N-arylsulfonamides under copper-catalyzed conditions at room temperature has been developed. The reaction employs various tert-butyl N-sulfonylcarbamates and diaryliodonium salts to avoid potential genotoxic impurities. A one-pot coupling/Boc-deprotection sequence is also reported to provide mono N-arylsulfonamides in good to excellent yields.

A one-pot, two-step synthesis of ureas (IX) using on-site prepared crude carbamates and secondary amines [cf.

An efficient coupling of a variety of sulfonyl azides with arylboronic acids proceeds in the presence of CuCl as catalyst and gives generally good yields of the corresponding N-aryl sulfonamides.

A mild and efficient method for the synthesis of N-arylsulfonamides in the presence of 10 mol % of CuCl is demonstrated. The reaction proceeds readily at room temperature in an open flask using a variety of sulfonyl azides and boronic acids without any base, ligand, or additive.