Science China Chemistry, Journal Year: 2023, Volume and Issue: 66(10), P. 2836 - 2841
Published: Sept. 5, 2023
Language: Английский
Science China Chemistry, Journal Year: 2023, Volume and Issue: 66(10), P. 2836 - 2841
Published: Sept. 5, 2023
Language: Английский
Accounts of Chemical Research, Journal Year: 2022, Volume and Issue: 56(2), P. 169 - 186
Published: Dec. 26, 2022
ConspectusThe past decades have witnessed tremendous progress on radical reactions. However, in comparison with carbon, nitrogen, oxygen, and other main group element centered radicals, the synthetic chemistry of boron radicals was less studied, mainly due to high electron-deficiency instability such 3-center-5-electron species. In 1980s, Roberts co-workers found that coordination a Lewis base (amines or phosphines) center could form 4-center-7-electron boryl (Lewis base-boryl LBRs) are be more stable. only limited applications were developed. 2008, Curran achieved breakthrough discovery N-heterocyclic carbene (NHC) which enable range reduction polymerization Despite these exciting findings, powerful valuable LBRs would expected, given structures reactivities easily modulated, provide ample opportunities discover new this Account, summary our key contributions LBR-enabled borylation reactions selective activation inert carbon-heteroatom bonds will presented.Organoboron compounds shown versatile chemical society, their syntheses rely principally ionic The development mechanistically different allows synthesizing products inaccessible by traditional methods. For purpose, we progressively developed series NHC-boryl mediated chemo-, regio-, stereoselective alkenes alkynes, wide variety structurally diverse organoboron molecules successfully prepared. utility borylated also demonstrated. Furthermore, disclosed photoredox protocol for oxidative generation enabled useful defluoroborylation arylboration reactions.Selective bond is an ideal way convert simple starting materials value-added products, while cleavage bonds, particular chemoselectivity control when multiple identical present similar environments, remains long-standing challenge. We envisaged finely tuning properties might solution address Recently, 4-dimethylaminopyridine (DMAP)-boryl promoted sequential C-F functionalization trifluoroacetic acid derivatives, α-C-F selectively snipped via spin-center shift mechanism. This strategy enables facile conversion abundantly available highly mono- difluorinated molecules. Encouraged finding, further three-step sequence construct all-carbon quaternary centers from trichloromethyl groups, where three C-Cl cleaved rational choice suitable precursors each step. dehydroxylative alkylation α-hydroxy carboxylic derivatives achieved, allowing efficient some biomass platform value products.
Language: Английский
Citations
73Journal 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
Citations
31Chemical Science, Journal Year: 2025, Volume and Issue: unknown
Published: Jan. 1, 2025
Nitriles stabilize neutral diarylboryl radicals, generating the RCN-BAr 2 complex, an efficient boron-nitrogen synthon that reacts with imines and olefins for photocatalytic synthesis of boron–nitrogen heterocycles, such as 1,4,2-diazaboroles.
Language: Английский
Citations
1Chemical Science, Journal Year: 2022, Volume and Issue: 13(45), P. 13466 - 13474
Published: Jan. 1, 2022
Despite the ubiquity of alkylboronic acids in organic synthesis, their utility as alkyl radical precursors visible-light-induced photocatalytic reactions is limited by high oxidation potentials. In this study, we demonstrated that an inorganophosphorus compound can modulate potentials so they act precursors. We propose a mechanism based on results fluorescence quenching experiments, electrochemical 11B and 31P NMR spectroscopy, other techniques. addition, describe simple reliable alkylation method has good functional group tolerance be used for direct C-B chlorination, cyanation, vinylation, alkynylation, allylation, well late-stage functionalization derivatized drug molecules. Notably, selectively activated presence boronic pinacol ester.
Language: Английский
Citations
30Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: unknown
Published: Sept. 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
Language: Английский
Citations
8Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(39)
Published: Aug. 9, 2023
Although the development of radical chain and photocatalytic borylation reactions using N-heterocyclic carbene (NHC)-borane as boron source is remarkable, persistent problems, including use hazardous high-energy initiators or recyclability photostability issues soluble homogeneous photocatalysts, still leave great room for further in a sustainable manner. Herein, we report conceptually different approach toward highly functionalized organoborane synthesis by recoverable ultrathin cadmium sulfide (CdS) nanosheets heterogeneous photocatalyst, general mild platform that enables regioselective wide variety alkenes (arylethenes, trifluoromethylalkenes, α,β-unsaturated carbonyl compounds nitriles), alkynes, imines electron-poor aromatic rings with NHC-borane boryl precursor. Mechanistic studies density functional theory (DFT) calculations reveal both photogenerated electrons holes on CdS fully perform their own roles, thereby resulting enhancement activity stability CdS.
Language: Английский
Citations
14Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(37)
Published: June 7, 2022
Functionalization of carboranes in a vertex-specific manner is perennial challenge. Here, we report photocatalytic B-C coupling for the selective functionalization at boron site which most distal to carbon. This reaction was achieved by photo-induced decarboxylation carborane carboxylic acids generate vertex-centered carboranyl radicals. Theoretical calculations also demonstrate that more easily occurs bearing higher electron density owing lower energy barrier single-electron transfer radical. By using this strategy, number functionalized could be accessed through alkylation, alkenylation, and heteroarylation under mild conditions. Moreover, both highly efficient blue emitter with solid-state luminous efficiency 42 % drug candidate neutron capture therapy (BNCT) containing targeting fluorine units were obtained.
Language: Английский
Citations
20Angewandte 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
Citations
13Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(36)
Published: June 15, 2024
Carborane compounds, known for their exceptional thermal stability and non-toxic attributes, have garnered widespread utility in medicine, supramolecular design, coordination/organometallic chemistry, others. Although there is considerable interest among chemists, the integration of suitable carborane molecules into ferroelectric materials remains a formidable challenge. In this study, we employ quasi-spherical design strategy to introduce functional groups at boron vertices o-carborane cage, aiming reduce molecular symmetry. This approach led successful synthesis pioneering crystals composed cage-like carboranes: 9-OH-o-carborane (1) 9-SH-o-carborane (2), which undergo above-room phase transitions (T
Language: Английский
Citations
5Organic Chemistry Frontiers, Journal Year: 2022, Volume and Issue: 9(18), P. 4975 - 4980
Published: Jan. 1, 2022
An efficient B(9) electrophilic amination of o -carboranes with azodicarboxylates, promoted by a Brønsted acid and HFIP, was developed.
Language: Английский
Citations
17