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.

Nucleophilic functionalization of thianthrenium salts under basic conditions
Abstract In recent years, S-(alkyl)thianthrenium salts have become an important means of functionalizing alcohol compounds. However, additional transition metal catalysts and/or visible light are required. Herein, a direct thioetherification/amination reaction of thianthrenium salts is realized under metal-free conditions. This strategy exhibits good functional-group tolerance, operational simplicity, and an extensive range of compatible substrates. Beilstein J. Org. Chem. 2024, 20, 257–263. doi:10.3762/bjoc.20.26 (Source: Beilstein Journal of Organic Chemistry)
Source: Beilstein Journal of Organic Chemistry - February 8, 2024 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: amination functionalization of alcohol metal-free S-(alkyl)thianthrenium salts thioetherification Full Research Paper Source Type: research

Catalytic multi-step domino and one-pot reactions
Beilstein J. Org. Chem. 2024, 20, 254–256. doi:10.3762/bjoc.20.25 (Source: Beilstein Journal of Organic Chemistry)
Source: Beilstein Journal of Organic Chemistry - February 8, 2024 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: domino reactions multi-step reactions multicomponent reactions one-pot synthesis organocatalysis tandem reactions transition-metal-catalysis Editorial Source Type: research

Photochromic derivatives of indigo: historical overview of development, challenges and applications
Abstract The importance of indigo dyes is constantly increasing with the evolution of novel textile materials and photochromic material technologies. The aim of this review article is to provide a comprehensive overview of the development of photochromic indigo derivatives from the first report on the photochromic N,N'-diacetylindigo in 1954 until now. We begin with the list of historical milestones in the development of photochromic indigo derivatives. Further, we provide a brief description of the synthetic procedures utilised to obtain indigo and its derivatives, outline the structural peculiarities, photophysical a...
Source: Beilstein Journal of Organic Chemistry - February 7, 2024 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: indigoid dyes photochemistry photophysics photoswitching – Z isomerization Review Source Type: research

Optimizations of lipid II synthesis: an essential glycolipid precursor in bacterial cell wall synthesis and a validated antibiotic target
Abstract Lipid II is an essential glycolipid found in bacteria. Accessing this valuable cell wall precursor is important both for studying cell wall synthesis and for studying/identifying novel antimicrobial compounds. Herein, we describe optimizations to the modular chemical synthesis of lipid II and unnatural analogues. In particular, the glycosylation step, a critical step in the formation of the central disaccharide unit (GlcNAc-MurNAc), was optimized. This was achieved by employing the use of glycosyl donors with diverse leaving groups. The key advantage of this approach lies in its adaptability, allowing for the gene...
Source: Beilstein Journal of Organic Chemistry - February 6, 2024 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: chemical glycosylation lipid II peptidoglycan polyprenyls total synthesis Full Research Paper Source Type: research

Copper-catalyzed multicomponent reaction of β -trifluoromethyl β -diazo esters enabling the synthesis of β -trifluoromethyl N,N-diacyl- β -amino esters
Abstract An efficient multicomponent reaction of newly designed β-trifluoromethyl β-diazo esters, acetonitrile, and carboxylic acids via an interrupted esterification process under copper-catalyzed conditions has been developed, which affords various unsymmetrical β-trifluoromethyl N,N-diacyl-β-amino esters in good to excellent yields. The reaction features mild conditions, a wide scope of β-amino esters and carboxylic acids, and also applicability to large-scale synthesis, thus providing an efficient way for the synthesis of β-trifluoromethyl β-diacylamino esters. Furthermore, this react...
Source: Beilstein Journal of Organic Chemistry - February 2, 2024 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: β -carbonyl diazo copper catalyst fluoroalkyl diazo Mumm rearrangement unsymmetrical -diacylamino esters Letter Source Type: research

Chiral phosphoric acid-catalyzed transfer hydrogenation of 3,3-difluoro-3H-indoles
Abstract A convenient and efficient method for the synthesis of optically active difluoro-substituted indoline derivatives starting from the corresponding 3H-indoles by chiral phosphoric acid-catalyzed transfer hydrogenation was developed. Using Hantzsch ester as the hydrogen source under mild reaction conditions, the target products can be obtained with excellent yield and enantioselectivity. Beilstein J. Org. Chem. 2024, 20, 205–211. doi:10.3762/bjoc.20.20 (Source: Beilstein Journal of Organic Chemistry)
Source: Beilstein Journal of Organic Chemistry - February 1, 2024 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: asymmetric organocatalysis chiral Br ø nsted acid 3,3-difluoroindoline Hantzsch ester transfer hydrogenation Letter Source Type: research

Comparison of glycosyl donors: a supramer approach
Abstract The development of new methods for chemical glycosylation commonly includes comparison of various glycosyl donors. An attempted comparison of chemical properties of two sialic acid-based thioglycoside glycosyl donors, differing only in the substituent at O-9 (trifluoroacetyl vs chloroacetyl), at different concentrations (0.05 and 0.15 mol·L−1) led to mutually excluding conclusions concerning their relative reactivity and selectivity, which prevented us from revealing a possible influence of remote protective groups at O-9 on glycosylation outcome. According to the results of the supramer analysis of the...
Source: Beilstein Journal of Organic Chemistry - January 31, 2024 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: concentration glycosylation protecting groups reactivity sialic acids stereoselectivity Full Research Paper Source Type: research

Metal-catalyzed coupling/carbonylative cyclizations for accessing dibenzodiazepinones: an expedient route to clozapine and other drugs
Abstract A sequential strategy to access 10,11-dihydro-5H-dibenzo[b,e][1,4]diazepinones (DBDAPs) is disclosed in this article through a palladium and copper-catalyzed amination (Buchwald–Hartwig (B–H) or Chan–Lam (C–L)) followed by a palladium-catalyzed intramolecular aminocarbonylation with Mo(CO)6 as CO surrogate (to avoid toxic CO handling) of readily available o-phenylenediamines and either 1,2-dibromobenzene or 2-bromophenylboronic acid. The 10,11-dihydro-5H-dibenzo[b,e][1,4]diazepinone could be synthezised in good yield using a sequential catalytic procedure, using both C–L and B–H...
Source: Beilstein Journal of Organic Chemistry - January 31, 2024 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: Buchwald – Hartwig carbonylative cyclization Chan Lam nitrogen heterocycle one-pot Full Research Paper Source Type: research

Synthesis of the 3 ’ -O-sulfated TF antigen with a TEG-N3 linker for glycodendrimersomes preparation to study lectin binding
Abstract The synthesis of gram quantities of the TF antigen (β-ᴅ-Gal-(1→3)-α-ᴅ-GalNAc) and its 3’-sulfated analogue with a TEG-N3 spacer attached is described. The synthesis of the TF antigen comprises seven steps, from a known N-Troc-protected galactosamine donor, with an overall yield of 31%. Both the spacer (85%) and the galactose moiety (79%) were introduced using thioglycoside donors in NIS/AgOTf-promoted glycosylation reactions. The 3’-sulfate was finally introduced through tin activation in benzene/DMF followed by treatment with a sulfur trioxide–trimethylamine complex i...
Source: Beilstein Journal of Organic Chemistry - January 30, 2024 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: regioselective sulfation thioglycoside donors Thomsen – Friedenreich antigen Full Research Paper Source Type: research

Tandem Hock and Friedel – Crafts reactions allowing an expedient synthesis of a cyclolignan-type scaffold
Abstract The Hock cleavage, which is compatible with tandem processes, was applied to the synthesis of 1-aryltetralines through a one-pot transformation from readily available benzyl(prenyl)malonate substrates. After the photooxygenation of the prenyl moiety, the resulting hydroperoxide was directly engaged in a Hock cleavage by adding a Lewis acid. The presence of an aromatic nucleophile in the reaction mixture and that of a benzyl moiety on the substrate resulted in tandem Friedel–Crafts reactions to form the 1-aryltetraline products. These compounds share a close analogy to the cyclolignan natural products. Experi...
Source: Beilstein Journal of Organic Chemistry - January 25, 2024 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: 1-aryltetralines Friedel – Crafts reaction Hock rearrangement oxidative cleavage tandem reactions Full Research Paper Source Type: research

Copper-promoted C5-selective bromination of 8-aminoquinoline amides with alkyl bromides
Abstract An efficient and practical method for the synthesis of C5-brominated 8-aminoquinoline amides via a copper-promoted selective bromination of 8-aminoquinoline amides with alkyl bromides was developed. The reaction proceeds smoothly in dimethyl sulfoxide (DMSO) under air, employing activated and unactivated alkyl bromides as the halogenation reagents without additional external oxidants. This method features outstanding site selectivity, broad substrate scope, and excellent yields. Beilstein J. Org. Chem. 2024, 20, 155–161. doi:10.3762/bjoc.20.14 (Source: Beilstein Journal of Organic Chemistry)
Source: Beilstein Journal of Organic Chemistry - January 23, 2024 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: aminoquinolines C – H bromination copper catalysis regioselectivity Full Research Paper Source Type: research

Perspectives on push – pull chromophores derived from click-type [2 + 2] cycloaddition – retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes
Abstract Various push–pull chromophores can be synthesized in a single and atom-economical step through [2 + 2] cycloaddition–retroelectrocyclization (CA–RE) reactions involving diverse electron-rich alkynes and electron-deficient alkenes. In this review, a comprehensive investigation of the recent and noteworthy advancements in the research on push–pull chromophores prepared via the [2 + 2] CA–RE reaction is conducted. In particular, an overview of the physicochemical properties of the family of these compounds that have been investigated is provided to clarify their potential for future appl...
Source: Beilstein Journal of Organic Chemistry - January 22, 2024 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: click chemistry donor – acceptor conjugate intramolecular charge transfer photoluminescence photoinduced electron transfer Review Source Type: research

Visible-light-induced radical cascade cyclization: a catalyst-free synthetic approach to trifluoromethylated heterocycles
Abstract A visible-light-promoted research protocol for constructing dihydropyrido[1,2-a]indolone skeletons is herein described proceeding through a cascade cyclization mediated by trifluoromethyl radicals. This method allows the efficient synthesis of various indole derivatives without the need of photocatalysts or transition-metal catalysts. Mechanism experiments indicate that the process involves a radical chain process initiated by the homolysis of Umemoto's reagent. This straightforward method enables a rapid access to heterocycles containing a trifluoromethyl group. Beilstein J. Org. Chem. 2024, 20, 118–12...
Source: Beilstein Journal of Organic Chemistry - January 19, 2024 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: cascade reaction indole derivatives photocatalysis radical chain process trifluoromethylation Full Research Paper Source Type: research

Photoinduced in situ generation of DNA-targeting ligands: DNA-binding and DNA-photodamaging properties of benzo[c]quinolizinium ions
Abstract The photoreactions of selected styrylpyridine derivatives to the corresponding benzo[c]quinolizinium ions are described. It is shown that these reactions are more efficient in aqueous solution (97–44%) than in organic solvents (78–20% in MeCN). The quinolizinium derivatives bind to DNA by intercalation with binding constants of 6–11 × 104 M−1, as shown by photometric and fluorimetric titrations as well as by CD- and LD-spectroscopic analyses. These ligand–DNA complexes can also be established in situ upon irradiation of the styrylpyridines and formation of the intercalator direct...
Source: Beilstein Journal of Organic Chemistry - January 18, 2024 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: DNA intercalators heterocycles photocyclization photosensitizer styrylpyridines Full Research Paper Source Type: research

Electron-beam-promoted fullerene dimerization in nanotubes: insights from DFT computations
Abstract Fullerene dimerization inside a peapod is analyzed at DFT level by characterizing the stationary points and deriving the energy profile of the initial and reversible process named phase 1. We find that the barriers for the radical cation mechanism are significantly lower than those found for the neutral pathway. The peapod is mainly providing one-dimensional confinement for the reaction to take place in a more efficient way. Car–Parrinello metadynamics simulations provide hints on structures for the initial steps of the irreversible phase 2 where bond formation and breaking lead to important structural reorg...
Source: Beilstein Journal of Organic Chemistry - January 17, 2024 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: DFT dimerization fullerene molecular dynamics peapods Full Research Paper Source Type: research