Facile Construction of New Hybrid Conjugation via Boron Cage Extension

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(6), С. 3577 - 3587

Опубликована: Фев. 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

Язык: Английский

---

Direct B–H Functionalization of Icosahedral Carboranes via Hydrogen Atom Transfer

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(13), С. 7638 - 7647

Опубликована: Март 22, 2023

The efficient and selective functionalization of icosahedral carboranes (C2B10H12) at the boron vertexes is a long-standing challenge owing to presence 10 inert B-H bonds in similar chemical environment. Herein, we report new reaction paradigm for direct via homolysis enabled by nitrogen-centered radical-mediated hydrogen atom transfer (HAT) strategy. Both HAT process carborane bond resulting boron-centered carboranyl radical intermediate have been confirmed experimentally. occurs most electron-rich vertex with lowest dissociation energy (BDE). Using this strategy, diverse derivatization, including thiolation, selenation, alkynylation, alkenylation, cyanation, halogenation, achieved satisfactory yields under photoinitiated condition metal-free redox-neutral fashion. Moreover, synthetic utility current protocol was also demonstrated both scale-up construction carborane-based functional molecules. Therefore, methodology opens pathway functionalization, which distinct from heterolytic mechanism traditional strategies.

Язык: Английский

---

B(9)-OH-o-Carboranes: Synthesis, Mechanism, and Property Exploration

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(13), С. 7331 - 7342

Опубликована: Март 24, 2023

Herein, we present a chemically robust and efficient synthesis route for B(9)-OH-o-carboranes by the oxidation of o-carboranes with commercially available 68% HNO3 under assistance trifluoromethanesulfonic acid (HOTf) hexafluoroisopropanol (HFIP). The reaction is highly wide scope carboranes, selectivity B(9)/B(8) up to 98:2. success this transformation relies on strong electrophilicity oxidizability HNO3, promoted through hydrogen bonds Brønsted HOTf solvent HFIP. Mechanism studies reveal that o-carborane involves an initial electrophilic attack atom at most electronegative B(9) o-carborane. In transformation, B-H bond nucleophilic site, which different from substitution reaction, where boron site. Therefore, oxidation-reduction mild conditions in N(V) → N(III) H(-I) H(I). derivatization 9-OH-o-carborane was further examined, carboranyl group successfully introduced amino acid, polyethylene glycol, biotin, deoxyuridine, saccharide. Undoubtedly, approach provides selective way rapid incorporation carborane moieties into small molecules application neutron capture therapy, requires targeted delivery boron-rich groups.

Язык: Английский

---

Photoinduced Selective B–H Activation of nido-Carboranes

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(11), С. 7791 - 7802

Опубликована: Март 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).

Язык: Английский

---

Facile synthesis of the dodecahydridododecaborate (B12H122−) from borane Lewis base adducts

Science China Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Янв. 2, 2025

Язык: Английский

---

Highly Stable Luminescent Metal–Organic Frameworks for Ultrasensitive Detection of Nitroaniline Isomers: Application in In Situ Imaging of Toxic Pesticides

ACS Sustainable Chemistry & Engineering, Год журнала: 2023, Номер 11(24), С. 9077 - 9086

Опубликована: Июнь 2, 2023

A powerful and promising route for developing chemically stable luminescent sensors visible sensing of toxic pesticides in water actual food samples is presented. Herein, a novel twofold interpenetrated metal–organic framework (MOF), Cd-TM, prepared by incorporating 2-methyl-1H-imidazole-5-carbaldehyde as the imidazole-containing tridentate coordination linker organic bridging 4,4′,4″-tricarboxyltriphenylamine (H3tca) into framework. Thanks to imidazole structurally nature, MOF exhibits high fluorescence stability up 6 months. Fluorescence titration experiments reveal that Cd-TM shows rapid ultrasensitive response p-nitroaniline compared with other nitroanilines limit detection about 8 nM. In particular, material also sensitivity detect dicloran (DCN, 2,6-dichloro-4-nitroaniline) structure similar p-NA. The 7.6 nM, which found be superior those recently reported MOF-based sensors. addition, mechanism DCN studied FT-IR analysis, SEM/EDX elemental mapping, XPS, theoretical calculations. Practically, recoveries spiked environmental were satisfactory (95.8–106.4%). Further, used situ nondestructive imaging pesticide residues simulated fresh agricultural products. These results indicate has potential organophosphorus contamination via easy-to-read visual signals.

Язык: Английский

---

A green and facile photochemical thiolate-catalyzed strategy for borylation of aryl fluorides with NHC–borane

Organic Chemistry Frontiers, Год журнала: 2024, Номер 11(5), С. 1462 - 1468

Опубликована: Янв. 1, 2024

Mild conditions, no photocatalyst, broad substrate scope.

Язык: Английский

---

Dative Bonding Activation Enables Precise Functionalization of the Remote B–H Bond of nido-Carborane Clusters

Journal of the American Chemical Society, Год журнала: 2024, Номер unknown

Опубликована: Сен. 13, 2024

The innovation of synthetic strategies for selective B-H functionalization is a pivotal objective in the realm boron cluster chemistry. However, precise, efficient, and rapid bond carboranes that distant from existing functional groups remains intractable owing to limited approaches site-selective control established methods. Herein, we report dative bonding activation strategy nonclassical remote site

Язык: Английский

---

Visible‐Light‐Induced Photoreduction of Carborane Phosphonium Salts: Efficient Synthesis of Carborane‐Oxindole‐Pharmaceutical Hybrids

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(31)

Опубликована: Апрель 29, 2023

Visible-light-induced photoreaction of carboranes is an effective approach to prepare carborane-containing compounds. While several methods involving boron-centered carboranyl radicals have been established, those for carbon-centered are underdeveloped, except the UV-light-promoted photohomolysis. Herein, we describe a simple but access by photoreduction carborane phosphonium salts under blue light irradiation without using transition metals and photocatalysts. The utility method was demonstrated successfully preparing range carborane-oxindole-pharmaceutical hybrids radical cascade reactions. Computational experimental studies suggest that generated single-electron transfer photoactive charge-transfer complexes between additive potassium acetate.

Язык: Английский

---

A strategy for regioselective B–H functionalization ofo-carboranesviabase metal catalysis

Organic Chemistry Frontiers, Год журнала: 2023, Номер 10(12), С. 3074 - 3079

Опубликована: Янв. 1, 2023

This frontier article summarizes the recent developments in base metal-catalyzed regioselective cage B–H functionalization of carboranes and discusses related challenging issues.

Язык: Английский

---