Bismuth Redox Catalysis: An Emerging Main-Group Platform for Organic Synthesis

ACS Catalysis, Год журнала: 2022, Номер 12(2), С. 1382 - 1393

Опубликована: Янв. 7, 2022

Bismuth has recently been shown to be able maneuver between different oxidation states, enabling access unique redox cycles that can harnessed in the context of organic synthesis. Indeed, various catalytic Bi platforms have discovered and revealed emerging opportunities field main group catalysis. The goal this perspective is provide an overview synthetic methodologies developed date, which capitalize on cycling. Recent methods via low-valent Bi(II)/Bi(III), Bi(I)/Bi(III), high-valent Bi(III)/Bi(V) couples are covered as well their underlying mechanisms key intermediates. In addition, we illustrate design strategies stabilizing bismuth species, highlight characteristic reactivity complexes, compared lighter p-block d-block elements. Although it not catalysis nature, also discuss a recent example non-Lewis acid, redox-neutral Bi(III) proceeding through organometallic steps. We close by discussing future directions hope Perspective will chemists with guiding principles for development transformations employing bismuth.

Язык: Английский

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Bismuth in Radical Chemistry and Catalysis

Angewandte Chemie International Edition, Год журнала: 2023, Номер 63(8)

Опубликована: Ноя. 22, 2023

Abstract Whereas indications of radical reactivity in bismuth compounds can be traced back to the 19 th century, preparation and characterization both transient persistent bismuth‐radical species has only been established recent decades. These advancements led emergence field chemistry, mirroring progress seen for other main‐group elements. The seminal fundamental studies this area have ultimately paved way development catalytic methodologies involving intermediates, a promising approach that remains largely untapped broad landscape synthetic organic chemistry. In review, we delve into milestones eventually present state‐of‐the‐art Our focus aims at outlining intrinsic discoveries inorganic/organometallic chemistry contextualizing their practical applications synthesis catalysis.

Язык: Английский

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Charge Makes a Difference: Molecular Ionic Bismuth Compounds

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(24)

Опубликована: Фев. 27, 2023

Key challenges in modern synthetic chemistry include the design of reliable, selective, and more sustainable methods, as well development promising candidates for new materials. Molecular bismuth compounds offer valuable opportunities they show an intriguing spectrum properties that is yet to be fully exploited: a soft character, rich coordination chemistry, availability broad variety oxidation states (at least +V -I) formal charges +3 -3) at Bi atoms, reversible switching between multiple states. All this paired with status non-precious (semi-)metal good tendency towards low toxicity. Recent findings some these only come into reach, or can substantially optimized, when charged are specifically addressed. In review, essential contributions synthesis, analyses, utilization ionic highlighted.

Язык: Английский

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Small molecule activation by well-defined compounds of heavy p-block elements

Chemical Communications, Год журнала: 2023, Номер 59(52), С. 8043 - 8058

Опубликована: Янв. 1, 2023

Recent advances in the activation of small molecules with well-defined molecular compounds heavy p-block elements (with a principle quantum number n > 4) are summarized, highlighting key strategies, challenges, and opportunities.

Язык: Английский

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Lewis Superacidic Heavy Pnictaalkene Cations: Comparative Assessment of Carbodicarbene-Stibenium and Carbodicarbene-Bismuthenium Ions

Inorganic Chemistry, Год журнала: 2022, Номер 61(46), С. 18640 - 18652

Опубликована: Ноя. 9, 2022

We report a comprehensive assessment of Lewis acidity for series carbone-stibenium and -bismuthenium ions using the Gutmann-Beckett (GB) method. These new antimony bismuth cations have been synthesized by halide abstractions from (CDC)PnBr3 [(pyCDC)PnBr2][Br] (CDC = carbodicarbene; Pn Sb or Bi; py pyridyl). The reaction (CDC)SbBr3 (1) with one two equivalents AgNTf2 (NTf2 bis(trifluoromethanesulfonyl)imide) AgSbF6 gives stibaalkene mono- dications form [(CDC)SbBr3-n][A]n (2-4; n 1,2; A NTf2 SbF6). trication [(CDC)2Sb][NTf2]3 (5) was also isolated collectively these molecules fill gap among cationic pnictaalkenes. are compared to related CDC-bismaalkene complexes 6-9. With goal preparing highly acidic compounds, tridentate bis(pyridine)carbodicarbene (pyCDC) used as ligand access (10, 12) trications [(pyCDC)Pn][NTf2]3 (Pn (11), Bi (13)), forgoing need second CDC in synthesis 5. bonding situation is elucidated through electron density energy decomposition analyses combination natural orbital chemical valence theory. In each complex, there exists CDC-Pn double interaction, consisting strong σ-bond weaker π-bond, whereby π-bond gradually strengthens increase charge complex. Notably, [(CDC)SbBr][NTf2]2 (4) has an acceptor number (AN) (84) that comparable quintessential acids such BF3, tricationic pnictaalkene 11 13 exhibit ANs 109 Sb) 84 Bi), respectively, which highest values reported any cation. Moreover, calculated fluoride ion affinities (FIAs) 99.8 94.3 kcal/mol, larger than SbF5 (85.1 kcal/mol), suggest superacids.

Язык: Английский

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Stabilizing Monoatomic Two-Coordinate Bismuth(I) and Bismuth(II) Using a Redox Noninnocent Bis(germylene) Ligand

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(9), С. 6025 - 6036

Опубликована: Фев. 26, 2024

The formation of isolable monatomic BiI complexes and BiII radical species is challenging due to the pronounced reducing nature metallic bismuth. Here, we report a convenient strategy tame atoms by taking advantage redox noninnocent character new chelating bis(germylene) ligand. remarkably stable novel cation complex 4, supported bis(iminophosphonamido-germylene)xanthene ligand [(P)GeII(Xant)GeII(P)] 1, [(P)GeII(Xant)GeII(P) = Ph2P(NtBu)2GeII(Xant)GeII(NtBu)2PPh2, Xant 9,9-dimethyl-xanthene-4,5-diyl], was synthesized two-electron reduction cationic BiIIII2 precursor 3 with cobaltocene (Cp2Co) in molar ratio 1:2. Notably, owing germylene moieties, positive charge 4 migrates one Ge ligand, giving rise germylium(germylene) as suggested DFT calculations X-ray photoelectron spectroscopy (XPS). Likewise, migration results bis(germylium)BiIIII2 complex. delocalization engenders much higher stability comparison an isoelectronic two-coordinate Pb0 analogue (plumbylone; decomposition below −30 °C). Interestingly, 4[BArF] undergoes reversible single-electron transfer (SET) reaction (oxidation) afford 5 5[BArF]2. According electron paramagnetic resonance (EPR) spectroscopy, unpaired predominantly resides at atom. Extending reactivity 4[OTf] employing AgOTf MeOTf affords BiIII(OTf)2 7 BiIIIMe 8, respectively, demonstrating high nucleophilic 4.

Язык: Английский

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Bismuth(III) compounds as catalysts in organic synthesis: A mini review

Polyhedron, Год журнала: 2022, Номер 222, С. 115765 - 115765

Опубликована: Март 16, 2022

Язык: Английский

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Bismuth Cations: Fluoride Ion Abstraction, Isocyanide Coordination, and Impact of Steric Bulk on Lewis Acidity

Chemistry - A European Journal, Год журнала: 2023, Номер 29(30)

Опубликована: Март 8, 2023

Abstract The molecular compound [BiDipp 2 (SbF 6 )], containing the bulky, donor‐free bismuth cation ] + has been synthesized and fully characterized (Dipp=2,6‐ i Pr ‐C H 3 ). Using its methyl analog [BiMe )] as a second reference point, impact of steric bulk on bismuth‐based Lewis acidity was investigated in combined experimental (Gutmann‐Beckett modified Gutmann‐Beckett methods) theoretical approach (DFT calculations). Reactivity studies cations towards [PF − neutral bases such isocyanides C≡NR’ revealed facile fluoride ion abstraction straightforward pair formation, respectively. first examples compounds featuring bismuth‐bound have isolated characterized.

Язык: Английский

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Reversing Lewis acidity from bismuth to antimony

Chemical Communications, Год журнала: 2021, Номер 57(71), С. 8889 - 8892

Опубликована: Янв. 1, 2021

Investigations on the boundaries between neutral and cationic models of (Mesityl) 2 EX (E = Sb, Bi X Cl − , OTf ) have facilitated reversing Lewis acidity from bismuth to antimony.

Язык: Английский

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A Multidimensional Approach to Carbodiphosphorane–Bismuth Coordination Chemistry: Cationization, Redox-Flexibility, and Stabilization of a Crystalline Bismuth Hydridoborate

Inorganic Chemistry, Год журнала: 2022, Номер 61(48), С. 19452 - 19462

Опубликована: Ноя. 22, 2022

Bismuth complexes stabilized by carbon-based donor ligands are underserved their instability, often due to facile ligand dissociation and deleterious protonolysis. Herein, we show that the ortho-bismuthination of hexaphenylcarbodiphosphorane enables a robust framework with geometrically constrained carbone-bismuth bonding interactions, which highly tunable cationization. The carbodiphosphorane bismuth halides (1 2) remarkably air-stable feature unprecedented transcarboneC-Bi-X ligation, resulting in elongated Bi-X bonds. In contrast known complexes, hydrolytic activation carbone yields well-defined organobismuth subsequent dehydrohalogenation is feasible using potassium bis(trimethylsilyl)amide or N-heterocyclic carbenes. redox-flexibility this was evaluated high catalytic activity 1 2 for silylation 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) under mild conditions (50 °C, 24-96 h) low catalyst loadings (5-10 mol %), suggests accessibility short-lived hydridic radical species. reaction 1, PhSiH3, tris(pentafluorophenyl)borane (BCF) first crystallographically characterized hydridoborate complex as an ionic species (9), presumably BCF-mediated hydride abstraction from unobserved [Bi]-H intermediate. All isolated compounds have been heteronuclear NMR spectroscopy X-ray crystallography, situation representative (1, 2, 5, 9) were further density functional theory.

Язык: Английский

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