MRV

Chemodivergent cross‐couplings are those in which either one of two (or more) potentially reactive functional groups can be made to react based on choice of conditions. In particular, this review focuses on cross‐couplings involving two different (pseudo)halides that can compete for the role of the electrophilic coupling partner. The discussion is primarily organized by pairs of electrophiles including chloride vs. triflate, bromide vs. triflate, chloride vs. tosylate, and halide vs. halide. Some common themes emerge regarding the origin of selectivity control. These include catalyst ligation state and solvent polarity or coordinating ability. However, in many cases, further systematic studies will be necessary to deconvolute the influences of metal identity, ligand, solvent, additives, nucleophilic coupling partner, and other factors on chemoselectivity.

Soft templating: Nitrogen‐doped mesoporous carbon nanosphere (NMCS) with tunable sizes and uniform mesoporosity is synthesized by a facile soft‐templating method, whereby F127 (PEO–PPO–PEO triblock copolymer) can be used not only as a soft template to generate the mesostructure but also as a size‐control agent to tailor the size of NMCS ranging from 100 to 700 nm.

Abstract

Nitrogen‐doped mesoporous carbon nanosphere (NMCS) with tunable sizes and uniform mesoporosity was synthesized by a facile soft‐templating method. During the synthesis, F127 (PEO–PPO–PEO triblock copolymer) could be used not only as a soft template to generate the mesostructure but also as a size‐control agent to tailor the size of NMCS in a relatively wide range of 100 to 700 nm. In addition, the synthesis process was simple and suitable for large‐scale production. Moreover, the NMCS was used as support of ultrafine Ru nanoparticles (Ru/NMCS), which exhibited good catalytic performances for selective hydrogenation of quinolones. It is expected that the simple synthetic strategy for the NMCS can generate extensive interest in many catalysis and sorption applications.

Synthesis
DOI: 10.1055/s-0040-1705970

We herein describe the two-step synthesis of 6-adamantyl-2-pyridone from 1-acetyladamantane. The borane complex derived from 6-adamantyl-2-pyridone and the Piers borane liberates dihydrogen at 60 °C. The reverse reaction, hydrogen activation by the formed pyridonate borane is accomplished under mild conditions. The mechanism of the hydrogen activation is studied by DFT computations.
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Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany

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The importance of fluorinated organic molecules in drugs and pharmaceuticals led to the development of several synthetic methods for introducing fluorine into bioactive molecules and trifluoromethylation is one of the key approaches for the same. Electrochemical organic synthesis has emerged as one of the most sustainable, green synthetic strategies in recent years and new developments in electroorganic synthesis also focus on electrochemical trifluoromethylation of organic compounds. A considerable number of reports have appeared in recent literature and this review surveys all the recent developments in electrochemical trifluoromethylation reactions. This highly sustainable protocol for trifluoromethylation will emerge further soon and pave the way for more energy‐efficient and green protocols.

Photo- and electrochemical transformations represent excellent opportunities for the development of methodologies environmentally friendly and combination of both techniques would result in improved methodologies. Recently, photochemical transformations involving the excitation of open-shell species has become a reality. Photostimulated electron transfer (PET) from radical anions of organic dyes have been used in consecutive photoredox catalysis and electro-photocatalysis transformation, allowing the transformation of aryl halides in valuable compounds under mild conditions. The similarities of both techniques raises the question of the convenience of using one or other related and a close evaluation is necessary to drive further development and have been shyly done in previous works. However, an objective comparison of both approaches will require using the same chemical system. We present here a direct comparison of a “pure” photochemical and an electrophotochemical transformartion studying a model transformation, namely, a C-H substitution in (hetero)aromatic systems with a C-C bond formation through reaction of halogenated substrates. Through a detailed investigation of both mechanisms, we identify a system that could be applied in both approaches with minor (necessaries) changes in the reaction conditions and clearly identify the excitation of radical anion of naphthalene diimides as the key intermediates. Both approaches are comparable in yields and kinetics with slightly better yields for the consecutive PET reaction and better selectivity for the electro-PET process. Our work offers a system that could be used for a more profound comparison of the experimental setups which could include, for instance, the important factor of energy consumption.

We herein disclose the use of an iron catalyst system for an intramolecular C–H amidation toward γ‐lactam synthesis from dioxazolone precursors. (Phthalocyanine)Fe(III)Cl was found to catalyze this cyclization with extremely high turnover numbers up to 47,000 under mild and aerobic conditions. On the basis of experimental and computational mechanistic studies, the reaction was suggested to proceed via a stepwise radical pathway involving fast hydrogen atom abstraction followed by radical rebound. Plausible origin of extremely high turnover numbers along with air‐compatibility was also rationalized.

Synlett
DOI: 10.1055/s-0040-1705955

In this Account, the development of Select Crowd Reviewing from the initial idea through a pilot phase to the present moment, when it is now used as the default method for the evaluation of manuscripts at Synlett and SynOpen is detailed. We describe the workflow through which a manuscript is evaluated when Select Crowd Reviewing is applied. A series of questions and answers is used to address typical concerns and the advantages Select Crowd Reviewing offers when compared to traditional peer review.1 Introduction: The History of Select Crowd Reviewing2 The Select Crowd Reviewing Workflow3 Questions We Have Received Regarding Select Crowd Reviewing4 Conclusion
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Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany

Article in Thieme eJournals:
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