Unraveling aromaticity: the dual worlds of pyrazole, pyrazoline, and 3D carborane

Beilstein Journal of Organic Chemistry, Год журнала: 2025, Номер 21, С. 412 - 420

Опубликована: Фев. 21, 2025

A new series of o -carborane-fused pyrazoles has been recently successfully synthesized. This fusion was expected to create a hybrid 3D/2D aromatic system, combining the 3D aromaticity -carborane with 2D pyrazole. However, while boron cage retains its character, pyrazole’s is lost. As result, rather than forming pyrazoles, synthesis yielded pyrazolines, which are non-aromatic. The limited overlap between π molecular orbitals (MOs) planar heterocycle and n + 1 MOs carborane prevents significant electronic delocalization two fused components. contrasts pyrazole benzene form indazole, where both rings maintain their aromaticity. Our findings demonstrate that peripheral σ-aromaticity π-aromaticity orthogonal, making true system unachievable. highly aromatic, generating negative NICS values (−25 −30 ppm). We have observed these high extend rings, leading incorrect estimations Therefore, relying solely on can be misleading, other computational indicators, along experimental or structural data, should used accurately assess

Язык: Английский

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Borirenes and Boriranes: Development and Perspectives

Chemistry - A European Journal, Год журнала: 2023, Номер 30(11)

Опубликована: Дек. 13, 2023

Strained compounds constitute a highly topical area of research in chemistry. Borirene and borirane both feature BC

Язык: Английский

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Iridium-Catalyzed Regioselective B(4)-Alkenylation and B(3,5)-Dialkenylation of o-Carboranes

Organic Letters, Год журнала: 2023, Номер 25(36), С. 6643 - 6648

Опубликована: Авг. 30, 2023

Iridium(I)-catalyzed regioselective B(4)-alkenylation has been developed from o-carboranyl sulfoxonium ylides and alkynes through B(4)–H activation. The sequential B(4)- B(6)-alkenylation afforded B(3,5)-dialkenylated in one pot. Eventually, two alkenyl groups, the same or different, were introduced at positions 3 5 of carborane. Sulfoxonium ylide used as a directing group remains available for further functionalization is converted to B-alkenylated trichloromethyl ketones.

Язык: Английский

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A Pd-catalyzed route to carborane-fused boron heterocycles

Chemical Science, Год журнала: 2024, Номер 15(27), С. 10392 - 10401

Опубликована: Янв. 1, 2024

A Pd-catalyzed cross-coupling system has been developed to achieve vicinal diamination of 9,10-dibromo-carborane with NH-heterocycles and anilines. These products can be further converted carborane-fused six- seven-membered heterocycles.

Язык: Английский

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Regiodivergent metal-catalyzed B(4)- and C(1)-selenylation of o-carboranes

Chemical Science, Год журнала: 2022, Номер 14(3), С. 643 - 649

Опубликована: Дек. 3, 2022

Regiodivergent transition metal-catalyzed B(4)- and C(1)-selenylation reactions of o -carboranes have been demonstrated.

Язык: Английский

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Iridium(III)-Catalyzed Regioselective B(4)–H Amination of o-Carboranes with Sufilimines

Organic Letters, Год журнала: 2023, Номер 25(32), С. 5989 - 5994

Опубликована: Авг. 4, 2023

Iridium(III)-catalyzed regioselective B(4)-H amination is developed from the reaction of o-carborane acids with sulfilimines without any oxidants under mild conditions, which leads to a wide range aminated o-carboranes in good yields broad substrate scope. Moreover, selective B(3,6)-diamination acid was achieved. The present attractive practical point view because dibenzothiophene quantitatively recovered and reused.

Язык: Английский

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Ruthenium‐Catalyzed Selective B(4)‐H Amidation of o‐Carboranes with Dioxazolones

Asian Journal of Organic Chemistry, Год журнала: 2022, Номер 12(3)

Опубликована: Дек. 21, 2022

Abstract A ruthenium‐catalyzed selective B4 amidation of o ‐carboranes with a variety alkyl‐, aryl‐, and heteroaryl‐substituted dioxazolones is developed by carboxylic acid‐assisted B(4)‐H bond activation in ‐carborane acids, affording multitude (4)‐amidated good yields the evolution carbon dioxide. In addition, two‐fold decarboxylative reaction cage was accomplished.

Язык: Английский

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Synthesis of o‐carboranyl‐acyl‐substituted diazo compounds from B(4)‐acylmethyl carboranes and 2‐azido‐1,3‐dimethylimidazolinium hexafluorophosphate

Bulletin of the Korean Chemical Society, Год журнала: 2023, Номер 44(8), С. 693 - 699

Опубликована: Апрель 28, 2023

Abstract Reaction of B(4)‐acylmethyl o ‐carborane with 2‐azido‐1,3‐dimethylimidazolinium hexafluorophosphate (ADMP) in the presence 1,8‐diazabicyclo[5.4.0]‐undec‐7‐ene (DBU) acetonitrile at 25 °C for 3 h produced a wide range ‐carboranyl‐acyl‐substituted diazo compounds high yields good functional group tolerance.

Язык: Английский

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Iridium(III)-catalyzed remote B(9)−H alkylation of o-carboranes with nitrile template

Research Square (Research Square), Год журнала: 2024, Номер unknown

Опубликована: Июль 24, 2024

Although the directing group assisted ortho-B − H activation reactions of o-carboranes have been well established during past decade, meta-B are unexplored so far. Herein, iridium(III)-catalyzed remote B(9) alkylation with nitrile template demonstrated for first time. It was revealed that fine tuning structures is essential high reaction efficiency and regioselectivity. This process exhibits a broad substrate scope good functional tolerance under simple conditions. The template, readily accessible from o-carborane acids, can be removed conveniently after completion reaction. present method provides powerful synthetic route to complex derivatives, demonstrating successful larger scale further molecular transformations B(9)-alkylated products.

Язык: Английский

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Rhodium(III)-Catalyzed B(4)-Azo Coupling of o-Carboranes with Aryl Diazonium Tetrafluoroborates

Organic Letters, Год журнала: 2024, Номер unknown

Опубликована: Сен. 25, 2024

Rh(III)-catalyzed B(4)-azo coupling reactions of

Язык: Английский

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