Functionalization of o-carboranes via carboryne intermediates

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(8), P. 3164 - 3180

Published: Jan. 1, 2022

Carborynes (1,2-dehydro-o-carborane and 1,3-dehydro-o-carborane), three-dimensional analogues of benzyne, can be generated in situ from the precursors 1-X-2-Li-1,2-C2B10H10 (X = Br, I, OTs, OTf), or 1-Me3Si-2-[IPh(OAc)]-1,2-C2B10H10 [1-Li-3-N2-1,2-C2B10H10][BF4]. They are a class very useful synthons for synthesis large variety functionalized carborane derivatives potential application medicine, materials science organometallic/coordination chemistry. The experimental data demonstrate that there is correspondence between reactions carborynes those benzyne with alkenes, dienes, alkynes, aromatics heteroaromatics pericyclic reaction fashion. On other hand, have unique properties their own owing to steric/electronic features. undergo regioselective sp2/sp3 C-H bond N-Li insertion reactions, which has not been observed benzyne. This review provides comprehensive overview recent advances this interesting research field considerable attention devoted modes mechanisms involved.

Language: Английский

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Facile Construction of New Hybrid Conjugation via Boron Cage Extension

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(6), P. 3577 - 3587

Published: Feb. 6, 2023

Aromatic polycyclic systems have been extensively utilized as structural subunits for the preparation of various functional molecules. Currently, aromatics-based are predominantly generated from extension two-dimensional (2D) aromatic rings. In contrast, compounds based on three-dimensional (3D) aromatics such boron clusters less studied. Here, we report three types cluster-cored tricyclic molecular systems, which constructed a 2D ring, 3D nido-carborane, and an alkyne. These new can be facilely accessed by Pd-catalyzed B-H activation subsequent cascade heteroannulation carborane pyridine with alkyne in isolated yield up to 85% under mild conditions without any additives. Computational results indicate that newly ring fusion carborane, pyridyl is non-aromatic. However, not only leads 1H chemical shift considerably downfield shifted owing strong diatropic current embedded but also devotes new/improved physicochemical properties including increased thermal stability, emergence absorption band, largely red-shifted emission band enhanced efficiency. Besides, number bright, color-tunable solid emitters spanning over all visible light obtained absolute luminescence efficiency 61%, contrast aggregation-caused quenching of, e.g., Rhodamine B containing 2D-aromatics-fused structure. This work demonstrates hybrid conjugated might promising scaffolds construction

Language: Английский

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Chemistry of three-dimensional icosahedral boron clusters anions: closo-dodecaborate (2-) [B12H12]2- and carba-closo-dodecaborate(-) [CB11H12]-

Coordination Chemistry Reviews, Journal Year: 2024, Volume and Issue: 516, P. 215974 - 215974

Published: June 8, 2024

Language: Английский

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Photoinduced Selective B–H Activation of nido-Carboranes

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(11), P. 7791 - 7802

Published: March 10, 2024

The development of new synthetic methods for B–H bond activation has been an important research area in boron cluster chemistry, which may provide opportunities to broaden the application scope clusters. Herein, we present a reaction strategy direct site-selective functionalization nido-carboranes initiated by photoinduced cage via noncovalent cage···π interaction. As result, nido-carborane radical is generated through single electron transfer from 3D 2D photocatalyst upon irradiation with green light. resulting transient could be directly probed advanced time-resolved EPR technique. In air, subsequent transformations active have led efficient and selective B–N, B–S, B–Se couplings presence N-heterocycles, imines, thioethers, thioamides, selenium ethers. This protocol also facilitates both late-stage modification drugs synthesis nido-carborane-based drug candidates neutron capture therapy (BNCT).

Language: Английский

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Organocatalytic Asymmetric Synthesis of o-Carboranyl Amines

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 14, 2025

Carboranyl amines are distinct from typical organic amines. Due to the electronic influence of carborane cage, they have low nucleophilicity and reluctant alkylate. Moreover, asymmetric synthesis chiral carboranes is still in its infancy. Herein we achieved first catalytic N-alkylation o-carboranyl amine, providing general access diverse secondary with high efficiency enantioselectivity under mild conditions. For time, organocatalysis was introduced chemistry. Key success use situ generated (naphtho-)quinone methides as alkylating reagents suitable acid catalysts. This protocol also applicable S-alkylation 1-SH-o-C2B10H11. Control experiments kinetic studies provided important insights into reaction mechanism, which likely involves rate-determining generation quinone methide followed by fast enantio-determining nucleophilic addition.

Language: Английский

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A variable bidentate traceless directing group for nickel-catalyzed regioselective B–H poly-chalcogenation of o-carboranes

Inorganic Chemistry Frontiers, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

A nickel-catalyzed direct cage B–H poly-chalcogenation of icosahedral carborane clusters, enabled by a variable bidentate 8-aminoquinoline traceless directing group, has been developed under oxidant-free and weakly basic conditions.

Language: Английский

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Synthesis of Carborane-Backbone Metallacycles for Highly Selective Capture ofn-Pentane

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(48), P. 22221 - 22228

Published: Nov. 28, 2022

The specific recognition and separation of alkanes with similar molecular structures close boiling points face significant scientific challenges industrial demands. Here, rectangular carborane-based metallacycles were designed to selectively encapsulate n-pentane from n-pentane, iso-pentane, cyclo-pentane mixtures in a simple-to-operate more energy-efficient way. Metallacycle 1, bearing 1,2-di(4-pyridyl) ethylene, can separate these three-component purity 97%. selectivity is ascribed the capture preferred guest matching size, C-H···π interactions, potential B-Hδ-···Hδ+-C interactions. Besides, removal gives rise original guest-free metallacycles, which be recycled without losing performance. Considering variety substituted carborane derivatives, metal ions, organic linkers, new supramolecular coordination complexes (SCCs) may broadly applicable other challenging systems good

Language: Английский

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Palladium-Catalyzed Cross-Coupling Reactions of Carboranes with Alkenes via Selective B–H Bond Activation

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 17, 2025

A palladium-catalyzed Heck-type cross-coupling reaction of carboranes with alkenes in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) was realized. This shows good B(9) selectivity for m-carboranes and is also suitable o- p-carborane. Meanwhile, a series mono-, di-, trisubstituted were compatible substrates to afford the alkenylated products 16–89% yields. The 1,2-bis(carboranyl)ethylene first synthesized by vinyltrimethylsilane m-carborane. Further transformations C═C bond product examined hydroboration oxidation, hydroboration, bromination generate corresponding B(9)-functionalized m-carboranes.

Language: Английский

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Iridium-Catalyzed Selective B(4)–H Acylmethylation of o-Carboranes with Sulfoxonium Ylides

Organic Letters, Journal Year: 2022, Volume and Issue: 24(6), P. 1318 - 1322

Published: Feb. 7, 2022

A highly efficient Ir-catalyzed regioselective cage B(4)-H acylmethylation of o-carboranyl acids using sulfoxonium ylides as alkylating regents has been developed, leading to the preparation a large class B(4)-acylmethylated o-carboranes in good excellent yields with broad substrate scope under redox neutral conditions. The -COOH moiety serves traceless directing group and controls regioselectivity monoselectivity.

Language: Английский

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Chiral‐at‐Cage Carboranes for Circularly Polarized Luminescence and Aggregation‐Induced Electrochemiluminescence

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(45)

Published: Sept. 14, 2022

Abstract Herein, we report the structures of chiral‐at‐cage carborane derivatives bearing carbazole chromophores that emit circularly polarized luminescence (CPL) and aggregation‐induced electrochemiluminescence (AIECL). By adjusting substituent positions on derivatives, two chiral luminescent molecules, Cb1 Cb2, with different properties were obtained. The photoluminescence dissymmetry factors | g PL both ( R / S)‐ Cb2 enantiomers in neat films as high 6.24×10 −3 7.38×10 , respectively. showed a deep blue emission peak at 434 nm n ‐pentane. Interestingly, distinct fluorescence CPL spectra observed solvents polarities due to twisted intramolecular charge transfer effect, suggesting its potential use solvent recognition. Meanwhile, exhibited good AIECL property, excellent ECL stability could be used for determining dopamine concentrations, applications biology diagnosis.

Language: Английский

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