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

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(13), P. 7638 - 7647

Published: March 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.

Language: Английский

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

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(31)

Published: April 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.

Language: Английский

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Visible‐Light‐Promoted Palladium‐Catalyzed Cross‐Coupling of Iodocarboranes with Disulfides and Phenylselenyl Chloride^†

Chinese Journal of Chemistry, Journal Year: 2023, Volume and Issue: 42(2), P. 129 - 134

Published: Sept. 19, 2023

Comprehensive Summary This work describes a general method for the synthesis of series sulfenylated and selenylated carboranes at room temperature using readily available iodocarboranes as starting materials via boron‐centered carboranyl radicals. Such hypervalent boron radicals are generated by visible‐light‐promoted Pd(0)/Pd(I) pathway. They useful intermediates can be trapped disulfides phenylselenyl chloride convenient construction B—S/Se bonds.

Language: Английский

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Charge Transfer Complex-Enabled Synthesis of (Hetero)arylated m-Carboranes from m-Carborane Phosphonium Salts

Organic Letters, Journal Year: 2023, Volume and Issue: 25(31), P. 5768 - 5773

Published: Aug. 3, 2023

A photoinduced charge transfer complex (CTC)-enabled photoreduction of carborane phosphonium salts for the cage carbon (hetero)arylation carboranes was developed. It offers a convenient approach introducing wide range aryl and heteroaryl groups, such as pyrroles, thiophenes, indoles, thianaphthenes, benzofurans, pyridines, benzenes, into carboranes. This strategy operational simplicity, mild reaction conditions, broad substrate scope, making it highly advantageous.

Language: Английский

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Carboranes meet photochemistry: Recent progresses in light-mediated cage functionalisation

Tetrahedron Letters, Journal Year: 2023, Volume and Issue: 131, P. 154782 - 154782

Published: Oct. 5, 2023

Carboranes are intriguing structures which show an excellent in vivo stability and high chemical versatility. Furthermore, thanks to their structural electronic properties they find many applications several fields, as smart materials, bioisosters of aryl rings knows drugs BNCT (Boron Neutron Capture Therapy) agents, for example. Recently, the reactivity these boron rich icosahedral cages, promoted by UV-visible light, has encountered interest some research groups, described new pathways based on formation B- C-centred radicals. In way, properly functionalised carboranes have been prepared, increasing precious moieties.

Language: Английский

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

Angewandte Chemie, Journal Year: 2023, Volume and Issue: 135(31)

Published: April 29, 2023

Abstract 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.

Language: Английский

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