An electrochemical cyclization/spirocyclization hydroarylation via reductive dearomatization of a series of nonactivated arenes including -substituted indoles, indole-3-carboxamide derivatives, and iodo-substituted benzamides is described. This protocol boasts high atom efficiency, broad substrate applicability, and excellent selectivity. Utilizing a simple undivided cell, various nonactivated arenes undergo cyclization/spirocyclization through the intramolecular addition of aryl radicals to an aromatic ring, yielding 50 indolines, spirocyclizative hydroarylation products, and phenanthridinones.
View Article and Find Full Text PDFA series of heterogeneous catalysts, designated as POP-n-Pd (where n = 1, 2, 3, or 4), were synthesized by polymerizing a six-membered N-heterocyclic compound with an alkyl substituted group monomer (S1), using divinylbenzene (DVB) as crosslinkers. This process was followed by the incorporation of palladium (Pd) nanoparticles. The impact of the substituted group and the S1:DVB ratio in the catalysts, together with the reaction conditions, was investigated to assess their influence on the catalytic performance in converting propylamine, carbon dioxide (CO) and 4-iodoanisole to oxazolidinones.
View Article and Find Full Text PDFChem Commun (Camb)
September 2024
Compounds comprising S-S bonds serve as significant pharmacological scaffolds in medicinal chemistry and natural products. We have devised an efficient electrochemical method for the construction of asymmetric disulfide bonds, leading to the synthesis of unsymmetric thiosulfonates. Compared with existing synthesis methods, our work not only avoids the use of metals and oxidants, but also realizes the operation of a one-pot three-component method, which makes this strategy extremely attractive.
View Article and Find Full Text PDFDithiocarbamate is a key structural sequence in pharmaceuticals and agrochemicals, and its synthesis is crucial in organic chemistry. Although significant progress has been made in related synthesis research, developing a practical and universal synthesis method remains fascinating. Herein, we report a new visible-light-induced decarboxylation coupling reaction between N-hydroxyphthalimide esters and tetraalkylthiuram disulfides, which uses Ir(ppy) as a photocatalyst to promote the generation of corresponding decarboxylation thioacylation product-dithiocarbamates in high yields.
View Article and Find Full Text PDFA mild and efficient electrochemical method for radical addition, cyclization, and migration reaction was described in this work. A difluoromethyl radical was produced by anodizing CFHSONa. The resulting product was then added to olefin, underwent Smiles cyclization, and migrated to form β-difluoromethamide compounds after the release of SO.
View Article and Find Full Text PDFAn electrochemical oxidative difunctionalization of diazo compounds with diselenides and nucleophiles has been developed. This innovative approach yields a diverse array of selenium-containing pyrazole esters and alkoxy esters, overcoming the limitations of traditional synthesis methods. Remarkably, various nucleophiles, including acids, alcohols, and pyrazoles, can be seamlessly incorporated.
View Article and Find Full Text PDFA method for the α-oxidation and sulfonation of benzyl secondary amines was developed utilizing Ir(III) or Eosin Y as the photocatalyst in the presence of O as a green oxidant. Using commercial substrates, 37 products from cyclic and acyclic benzylamines were achieved with good functional group compatibility in 48-87% yields. Furthermore, tetrahydroisoquinoline protected by an Ac or a Boc group was oxidized under standard conditions.
View Article and Find Full Text PDFIn this study, a multicomponent reaction via the Mannich intermediate was developed using methanol, secondary amine, and sulfonamide as starting materials. This method uses methanol as a green C1 source. The substrate scope is wide, and the yield is good.
View Article and Find Full Text PDFAlkenylboronates are highly versatile building blocks and valuable reagents in the synthesis of complex molecules. Compared with that of monosubstituted alkenylboronates, the synthesis of multisubstituted alkenylboronates is challenging. The copper-catalyzed carboboration of alkynes is an operationally simple and straightforward method for synthesizing bis/trisubstituted alkenylboronates.
View Article and Find Full Text PDFEfficient utilizing CO is crucial approaches in achieving carbon neutralization. One of the challenges lies in the in-situ conversion of low concentration CO found in waste gases. This study introduces a novel heterogeneous catalyst known as silver nanoparticles in porous N-heterocyclic carbene polymer (Ag@POP-NL-3).
View Article and Find Full Text PDFAn electrochemical facilitated three-component trifluoromethylation/spirocyclization reaction of -(arylsulfonyl)acrylamides, CFSONa, and HO has been developed. Without the requirement of chemical oxidants, a number of unexplored trifluoromethylated 4-azaspiro[4.5]decanes were obtained in satisfactory yields under mild conditions.
View Article and Find Full Text PDFDuring the chlor-alkali process, in operation since the nineteenth century, electrolysis of sodium chloride solutions generates chlorine and sodium hydroxide that are both important for chemical manufacturing. As the process is very energy intensive, with 4% of globally produced electricity (about 150 TWh) going to the chlor-alkali industry, even modest efficiency improvements can deliver substantial cost and energy savings. A particular focus in this regard is the demanding chlorine evolution reaction, for which the state-of-the-art electrocatalyst is still the dimensionally stable anode developed decades ago.
View Article and Find Full Text PDFAzoles and organoselenium compounds are pharmacologically important scaffolds in medicinal chemistry and natural products. We developed an efficient regioselective electrochemical aminoselenation reaction of 1,3-dienes, azoles, and diselenide derivatives to access selenium-containing allylazoles skeletons. This protocol is more economical and environmentally friendly and features a broad substrate scope; pyrazole, triazole, and tetrazolium were all tolerated under the standard conditions, which could be applied to the expedient synthesis of bioactive molecules and in the pharmaceutical industry.
View Article and Find Full Text PDFThe electrocatalytic ring-opening dihydroalkoxylation of -aryl maleimides with alcohols under metal- and oxidant-free conditions is described. This electrochemical process consists of anodic single-electron transfer oxidation, cathodic radical reduction, rearrangement-ring cleavage and nucleophilic addition cascade, which employs tetrabutylammonium bromide not only as a redox catalyst but also as an efficient supporting electrolyte, and offers a practical and environmentally friendly route to ring-opening difunctionalization products.
View Article and Find Full Text PDFIndustrial waste gas is one of the major sources of atmospheric CO , yet the direct conversion of the low concentrations of CO in waste gases into high value-added chemicals have been a great challenge. Herein, a copper-based N-heterocyclic carbene porous polymer catalyst (Cu@NHC-1) for the direct conversion of low concentration CO into oxazolidinones was successfully fabricated via a facile copolymerization process followed by the complexation with Cu(OAc) . A continuous flow device was designed to deliver a continuous and stable carbon source for the reaction.
View Article and Find Full Text PDFCO is an important C1 resource. We report a method for the synthesis of pharmacologically active 2-oxazolidinones by reacting CO with allylic amines. As opposed to previous addition reactions, the unsaturated double bonds are preserved.
View Article and Find Full Text PDFGiven the importance of both the CF group and the alkyne moiety in synthetic/medicinal chemistry, we report here the first example of efficient synthesis of 2-pyrazolines with a CF- and alkyne-substituted quaternary carbon center. This methodology has the advantages of high functional group compatibility, the avoidance of base and open-flask conditions, easily available and easy to handle reagent, and broad substrate scope. Notably, this protocol allows for the late-stage functionalization of biologically active molecules and the gram-scale synthesis.
View Article and Find Full Text PDFImproving the stability of sensitive catalytic systems is an emerging research topic in the catalysis field. However, the current design of heterogeneous catalysts mainly improves their catalytic performance. This paper presents a single-atom catalyst (SAC) strategy to improve the cobalt-catalysed fluorination of acyl chlorides.
View Article and Find Full Text PDFAn efficient one-pot reaction for the synthesis of oxoaporphine alkaloids has been developed. Twenty-three compounds of oxoaporphine alkaloids were prepared and assessed for their antitumor activities. Most compounds inhibited the growth of T-24 tumor cells in vitro.
View Article and Find Full Text PDFThe study reported an electrochemically mediated method for the preparation of 2,1-benzoxazoles from -nitrophenylacetylenes. Different from the traditional electrochemical reduction of nitro to nitroso, the nitro group directly underwent a cyclization reaction with the alkyne activated by selenium cation generated by the anodic oxidation of diphenyl diselenide and finally produced the desired products.
View Article and Find Full Text PDFIn general, halogenide anions are anodically oxidized into active species, which can be elemental halogen, halogen cations, or halogen radicals. These species subsequently react with substrates, such as olefins, ketones, or amines, to generate halogenated products. We review the mechanisms of these reactions.
View Article and Find Full Text PDFA convenient and efficient palladium-catalyzed approach has been developed for the synthesis of 5-amino-1,2,4-oxadiazoles from amidoximes and isocyanides. Various 5-amino-1,2,4-oxadiazoles were obtained in moderate to high yields under mild conditions. The key to the success of this strategy involves new C-N bond and C-O bond formation via palladium-catalyzed isocyanide insertion.
View Article and Find Full Text PDFAn environmentally benign electrochemically enabled site-selective functionalization of indole or aniline derivatives with hexafluoroisopropanol in the presence of tetrabutyl ammonium hexafluorophosphate as the redox catalyst and electrolyte was demonstrated in this work. Under mild electro-oxidation conditions, a series of hexafluoroisopropoxy indole and aniline derivatives with pharmacological activity were obtained. This conversion does not need transition metals and oxidants, and has good functional group tolerance.
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