Beilstein Journal of Organic Chemistry This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

Photoredox catalysis harvesting multiple photon or electrochemical energies
Abstract Photoredox catalysis (PRC) is a cutting-edge frontier for single electron-transfer (SET) reactions, enabling the generation of reactive intermediates for both oxidative and reductive processes via photon activation of a catalyst. Although this represents a significant step towards chemoselective and, more generally, sustainable chemistry, its efficacy is limited by the energy of visible light photons. Nowadays, excellent alternative conditions are available to overcome these limitations, harvesting two different but correlated concepts: the use of multi-photon processes such as consecutive photoinduced electron tr...
Source: Beilstein Journal of Organic Chemistry - July 28, 2023 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: consecutive photoinduced electron transfer electro-activated photoredox catalysis photoelectrochemistry radical ions Review Source Type: research

The effect of dark states on the intersystem crossing and thermally activated delayed fluorescence of naphthalimide-phenothiazine dyads
Abstract A series of 1,8-naphthalimide (NI)-phenothiazine (PTZ) electron donor–acceptor dyads were prepared to study the thermally activated delayed fluorescence (TADF) properties of the dyads, from a point of view of detection of the various transient species. The photophysical properties of the dyads were tuned by changing the electron-donating and the electron-withdrawing capability of the PTZ and NI moieties, respectively, by oxidation of the PTZ unit, or by using different aryl substituents attached to the NI unit. This tuning effect was manifested in the UV–vis absorption and fluorescence emission spectra...
Source: Beilstein Journal of Organic Chemistry - July 19, 2023 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: charge-transfer electron donor intersystem crossing TADF triplet state Full Research Paper Source Type: research

CO2 complexation with cyclodextrins
Abstract Carbon dioxide (CO2) emissions from industrial processes, power generation, and transportation contribute significantly to global warming and climate change. Carbon capture and storage (CCS) technologies are essential to reduce these emissions and mitigate the effects of climate change. Cyclodextrins (CDs), cyclic oligosaccharides, are studied as potential CO2 capture agents due to their unique molecular structures and high selectivity towards CO2. In this paper we have investigated binding efficiency of a number of cyclodextrins towards CO2. It is found that the crystal structure of α-cyclodextrin with CO2 h...
Source: Beilstein Journal of Organic Chemistry - July 17, 2023 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: carbon dioxide crystals cyclodextrin gas binding Full Research Paper Source Type: research

Linker, loading, and reaction scale influence automated glycan assembly
Abstract Automated glycan assembly (AGA) affords collections of well-defined glycans in a short amount of time. We systematically analyzed how parameters connected to the solid support affect the AGA outcome for three different glycan sequences. We showed that, while loading and reaction scale did not significantly influence the AGA outcome, the chemical nature of the linker dramatically altered the isolated yields. We identified that the major determinants of AGA yields are cleavage from the solid support and post-AGA purification steps. Beilstein J. Org. Chem. 2023, 19, 1015–1020. doi:10.3762/bjoc.19.77 (Sour...
Source: Beilstein Journal of Organic Chemistry - July 6, 2023 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: automated glycan assembly photocleavable linker polysaccharides solid-phase synthesis Letter Source Type: research

Copper-catalyzed N-arylation of amines with aryliodonium ylides in water
Abstract Copper sulfate catalyzed an efficient, inexpensive, and environment-friendly protocol that has been developed for N-arylation of amines with 1,3-cyclohexadione-derived aryliodonium ylides in water as a green solvent. Aromatic primary amines substituted with electron-donating as well as electron-withdrawing groups on the aryl ring reacted smoothly with iodonium ylides to give the corresponding diarylamines with good to excellent yields. Also, secondary amines underwent N-arylation to deliver tertiary amines with moderate yields. Beilstein J. Org. Chem. 2023, 19, 1008–1014. doi:10.3762/bjoc.19.76 (Source...
Source: Beilstein Journal of Organic Chemistry - July 4, 2023 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: amines arylation C – N bond formation iodonium ylide sustainable Letter Source Type: research

Synthesis of tetrahydrofuro[3,2-c]pyridines via Pictet – Spengler reaction
Abstract A semi-one-pot method for the synthesis of 4-substituted tetrahydrofuro[3,2-c]pyridines by the Pictet–Spengler reaction was developed. The method is based on the condensation of easily accessibly 2-(5-methylfuran-2-yl)ethanamine with commercially available aromatic aldehydes followed by acid-catalyzed Pictet–Spengler cyclization. Using this approach, we synthesized a range of 4-substituted tetrahydrofuro[3,2-c]pyridines in reasonable yields. The reactivity of some of the products was investigated and selected synthetic transformations of the obtained tetrahydrofuro[3,2-c]pyridines were shown. Beilstei...
Source: Beilstein Journal of Organic Chemistry - June 30, 2023 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: acid hydrolysis 1,4-diketone tetrahydrofuro[3,2-c]pyridines Paal – Knorr reaction Pictet Spengler reaction Full Research Paper Source Type: research

Five new sesquiterpenoids from agarwood of Aquilaria sinensis
Abstract Five new eudesmane-type sesquiterpenoids (aquisinenoids F–J (1–5)) and five known compounds (6–10) were isolated from the agarwood of Aquilaria sinensis. Their structures, including absolute configurations, were identified by comprehensive spectroscopic analyses and computational methods. Inspired by our previous study on the same kinds of skeletons, we speculated that the new compounds have anticancer and anti-inflammatory activities. The results did not show any activity, but they revealed the structure–activity relationships (SAR). Beilstein J. Org. Chem. 2023, 19, 998–1007. ...
Source: Beilstein Journal of Organic Chemistry - June 30, 2023 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: agarwood Aquilaria sinensis SAR studies sesquiterpenoids Full Research Paper Source Type: research

The unique reactivity of 5,6-unsubstituted 1,4-dihydropyridine in the Huisgen 1,4-diploar cycloaddition and formal [2 + 2] cycloaddition
Abstract The three-component reaction of isoquinolines, dialkyl acetylenedicarboxylates, and 5,6-unsubstituted 1,4-dihydropyridines in acetonitrile at room temperature afforded functionalized isoquinolino[1,2-f][1,6]naphthyridines in good yields and with high diastereoselectivity. More importantly, the formal [2 + 2] cycloaddition reaction of dialkyl acetylenedicarboxylates and 5,6-unsubstituted 1,4-dihydropyridines in refluxing acetonitrile gave unique 2-azabicyclo[4.2.0]octa-3,7-dienes as major products and 1,3a,4,6a-tetrahydrocyclopenta[b]pyrroles as minor products via further rearrangement. Beilstein J. Org. Chem. 202...
Source: Beilstein Journal of Organic Chemistry - June 29, 2023 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: 1,4-dihydropyridine electron-withdrawing alkyne formal [2 2] cycloaddition Huisgen ' s 1,4-dipole isoquinoline isoquinolino[1,2-f][1,6]naphthyridine Full Research Paper Source Type: research

Aromatic C – H bond functionalization through organocatalyzed asymmetric intermolecular aza-Friedel – Crafts reaction: a recent update
Abstract The aza-Friedel–Crafts reaction allows an efficient coupling of electron-rich aromatic systems with imines for the facile incorporation of aminoalkyl groups into the aromatic ring. This reaction has a great scope of forming aza-stereocenters which can be tuned by different asymmetric catalysts. This review assembles recent advances in asymmetric aza-Friedel–Crafts reactions mediated by organocatalysts. The mechanistic interpretation with the origin of stereoselectivity is also explained. Beilstein J. Org. Chem. 2023, 19, 956–981. doi:10.3762/bjoc.19.72 (Source: Beilstein Journal of Organic Chemistry)
Source: Beilstein Journal of Organic Chemistry - June 28, 2023 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: asymmetric aza-Friedel – Crafts reaction H-bonding organocatalysis stereoselectivity Review Source Type: research

Clauson – Kaas pyrrole synthesis using diverse catalysts: a transition from conventional to greener approach
Abstract Pyrrole is an important aromatic heterocyclic scaffold found in many natural products and predominantly used in pharmaceuticals. Continuous efforts are being made to design and synthesize various pyrrole derivatives using different synthetic procedures. Among them, the Clauson–Kaas reaction is a very old and well-known method for synthesizing a large number of N-substituted pyrroles. In recent years, due to global warming and environmental concern, research laboratories and pharmaceutical industries around the world are searching for more environmentally friendly reaction conditions for synthesizing compound...
Source: Beilstein Journal of Organic Chemistry - June 27, 2023 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: catalyst Clauson – Kaas pyrrole synthesis 2,5-dimethoxytetrahydrofuran green synthesis microwave-assisted reaction N-substituted pyrrole Review Source Type: research

Photoredox catalysis enabling decarboxylative radical cyclization of γ , γ -dimethylallyltryptophan (DMAT) derivatives: formal synthesis of 6,7-secoagroclavine
Abstract An unusual photoredox-catalyzed radical decarboxylative cyclization cascade reaction of γ,γ-dimethylallyltryptophan (DMAT) derivatives containing unactivated alkene moieties has been developed, providing green and efficient access to various six-, seven-, and eight-membered ring 3,4-fused tricyclic indoles. This type of cyclization, which was hitherto very difficult to comprehend in ergot biosynthesis and to accomplish by more conventional procedures, enables the synthesis of ergot alkaloid precursors. In addition, this work describes a mild, environmentally friendly method to activate, reductively and o...
Source: Beilstein Journal of Organic Chemistry - June 26, 2023 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: decarboxylative cyclization DMAT ergot alkaloids photoredox catalysis radicals Full Research Paper Source Type: research

Intermediates and shunt products of massiliachelin biosynthesis in Massilia sp. NR 4-1
Abstract Siderophores are small molecules secreted by microorganisms in order to scavenge iron from the environment. An example is the thiazoline-containing natural product massiliachelin, which is produced by Massilia sp. NR 4-1 under iron-deficient conditions. Based on experimental evidence and genome analysis, it was suspected that this bacterium synthesizes further iron-chelating molecules. After a thorough inspection of its metabolic profile, six previously overlooked compounds were isolated that were active in the chrome azurol S (CAS) assay. Mass spectrometric measurements and nuclear magnetic resonance spectroscopi...
Source: Beilstein Journal of Organic Chemistry - June 23, 2023 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: Massilia massiliachelin siderophore structure elucidation Full Research Paper Source Type: research

Synthesis of aliphatic nitriles from cyclobutanone oxime mediated by sulfuryl fluoride (SO2F2)
Abstract A SO2F2-mediated ring-opening cross-coupling of cyclobutanone oxime derivatives with alkenes was developed for the construction of a range of δ-olefin-containing aliphatic nitriles with (E)-configuration selectivity. This new method features wide substrate scope, mild conditions, and direct N–O activation. Beilstein J. Org. Chem. 2023, 19, 901–908. doi:10.3762/bjoc.19.68 (Source: Beilstein Journal of Organic Chemistry)
Source: Beilstein Journal of Organic Chemistry - June 22, 2023 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: direct N – O activation E-selectivity nitrile synthesis ring-opening cross-coupling sulfuryl fluoride SO2F2 Letter Source Type: research

First synthesis of acylated nitrocyclopropanes
Abstract Although nitrocyclopropanedicarboxylic acid esters are widely used in organic syntheses, nitrocyclopropanes with an acyl group have not yet been synthesized. When adducts of β-nitrostyrene and 1,3-dicarbonyl compounds are treated with (diacetoxyiodo)benzene and tetrabutylammonium iodide, iodination occurs at the α-position of the nitro group, and the subsequent O-attack of the enol moiety leads to 2,3-dihydrofuran. Cyclopropane was successfully synthesized through C-attack as the acyl group became bulkier. The obtained nitrocyclopropane was transformed into furan upon treatment with tin(II) chloride via ...
Source: Beilstein Journal of Organic Chemistry - June 21, 2023 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: acetoxyiodine conjugate addition dihydrofuran nitroalkene nitrocyclopropane Full Research Paper Source Type: research

Cyclodextrins as building blocks for new materials
Beilstein J. Org. Chem. 2023, 19, 889–891. doi:10.3762/bjoc.19.66 (Source: Beilstein Journal of Organic Chemistry)
Source: Beilstein Journal of Organic Chemistry - June 19, 2023 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: building blocks cyclodextrins new materials Editorial Source Type: research