The transition metal-catalysed hydroboration reaction

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(21), P. 8877 - 8922

Published: Jan. 1, 2022

This review covers the development of transition metal-catalysed hydroboration reaction, from its beginnings in 1980s to more recent developments including earth-abundant catalysts and an ever-expanding array substrates.

Language: Английский

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Green Utilizing AlFeO3 Nanoparticles-Catalyzed for Sustainable Biginelli Synthesis of 3, 4-Dihydropyrimidin-2(1H)-thiones in Glycerol

Catalysis Surveys from Asia, Journal Year: 2025, Volume and Issue: unknown

Published: March 11, 2025

Language: Английский

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Metal‐Free Catalytic Hydroboration of Unsaturated Compounds: A Greener Strategy for the Synthesis of Organoboranes

ChemCatChem, Journal Year: 2022, Volume and Issue: 15(2)

Published: Nov. 24, 2022

Abstract This review discusses the immense progress made over recent years in metal‐free catalytic hydroboration. Reactions with several unsaturated functional groups, such as alkynes, alkenes, carbonyl compounds, carbon dioxide, carbodiimides, imines, allenes, pyridines, carboxylic acid derivatives etc., have been explored. Although there are significant developments hydroboration reactions using metal‐based catalysts, strategies more desirable from a sustainability perspective. Considerable effort has by various research groups on catalysts of compounds. Lewis acid, Brønsted acid‐base pairs, and frustrated pairs were involved sources to catalyze sustainable manner. Detailed mechanisms pathways also discussed this review. discussion will provide an overview extent work carried out well indicate scope for future research.

Language: Английский

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Intermediates, Isolation and Mechanistic Insights into Zinc Hydride-Catalyzed 1,2-Regioselective Hydrofunctionalization of N-Heteroarenes

Inorganic Chemistry, Journal Year: 2022, Volume and Issue: 62(1), P. 304 - 317

Published: Dec. 26, 2022

The conjugated bis-guanidinate-supported zinc hydride [{LZnH}2; L = {(ArHN) (ArN)-C═N-C═(NAr) (NHAr); Ar 2,6-Et2-C6H3}] (I)-catalyzed highly demanding exclusive 1,2-regioselective hydroboration and hydrosilylation of N-heteroarenes is demonstrated with excellent yields. This protocol compatible many pyridines N-heteroarene derivatives, including electron-donating -withdrawing substituents. Catalytic intermediates, such as [(LZnH) (4-methylpyridine)] IIA, [(L'ZnH) (4-methylpyridine) IIA', where L' CH{(CMe) (2,6-Et2C6H3N)}2)], LZn(1,2-DhiQ) (isoquinoline) III, [L'Zn(1,2-DhiQ) (isoquinoline)] III', LZn(1,2-(3-MeDHQ)) (3-methylquinoline) V, were isolated thoroughly characterized by NMR, HRMS, IR analyses. Furthermore, X-ray single-crystal diffraction studies confirmed the molecular structures compounds III'. NMR data proved that intermediate III or III' reacted HBpin gave a selective 1,2-addition hydroborated product. Stoichiometric experiments suggest V independently silane, yielding mono- bis-hydrosilylated products, respectively. Based on isolation intermediates series stoichiometric experiments, plausible catalytic cycles established. intermolecular chemoselective reaction over other reducible functionalities was studied.

Language: Английский

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Machine-learnt potential highlights melting and freezing of aluminum nanoparticles

The Journal of Chemical Physics, Journal Year: 2025, Volume and Issue: 162(14)

Published: April 8, 2025

We investigated the complete thermodynamic cycle of aluminum nanoparticles through classical molecular dynamics simulations, spanning a wide size range from 200 atoms to 11 000 atoms. The aluminum–aluminum interactions are modeled using newly developed Bayesian Force Field (BFF) FLARE suite, cutting-edge tool in our field. discuss database requirements include melted nanodroplets avoid unphysical behavior at phase transition. Our study provides comprehensive understanding structural stability up sizes as large 3 × 105 Al-BFF predicts an icosahedral 2000 atoms, ∼2 nm, followed by region for decahedra, 25 Beyond this size, expected structure favors face-centered cubic shapes. At fixed heating/cooling rate 100 K/ns, we consistently observe hysteresis loop, where melting temperatures higher than those associated with solidification. annealing liquid droplet further stabilizes structures, extending their 5000 Using hierarchical k-means clustering, find no evidence surface but some mild indication freezing. In any event, droplet’s shows local order all sizes.

Language: Английский

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Lithium diisobutyl‐tert‐butoxyaluminum hydride promoted ester hydroboration: An efficient protocol under solvent‐free conditions at room temperature

Bulletin of the Korean Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: April 23, 2025

Abstract Ester‐to‐alcohol reductions under green conditions (low catalyst loadings, solvent‐free, room temperature, non‐toxic, minimal by‐products) are highly desirable in the organic‐synthesis field. In this context, we report use of an aluminum‐based as a practical and robust method for hydroborating esters. Lithium diisobutyl‐ tert ‐butoxyaluminum hydride (LDBBA), four‐coordinate lithium‐ion‐based aluminum reagent, significantly reduces esters to their corresponding boronates presence pinacolborane (HBpin) extremely mild conditions. Furthermore, LDBBA was found be superior other examined hydrides. Gram‐scale hydroboration chemoselective reduction reactions also reported.

Language: Английский

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Hydroboration of Imines and Alkynes Catalyzed by Electronically Unsaturated Aluminum Hydride and Methyl Aluminum Cations

Inorganic Chemistry, Journal Year: 2023, Volume and Issue: 62(17), P. 6598 - 6607

Published: April 14, 2023

Aluminum hydride cations, [LAlH]+[HB(C6F5)3]- (1) and [LAlH]+[B(C6F5)4]- (2), the methyl aluminum cation, [LAlMe]+[B(C6F5)4]- (3) (L = [{(2,6-iPr2C6H3N)P(Ph2)}2N]), due to their electronic coordinative unsaturation at Al center, exhibit high Lewis acidity have been exploited for catalytic hydroboration (using HBpin/HBcat) of a variety imines alkynes. These catalysts, under mild reaction conditions, afford excellent yields respective products. Thorough mechanistic investigations performed using series stoichiometric experiments successful isolation key intermediates was accomplished. The obtained results demonstrate predominant acid activation mechanism over pathways previously reported covalent complexes catalyzed imines. title cations form adducts with which are thoroughly characterized via multinuclear NMR measurements. For alkynes, detailed study most efficient catalyst 2 supports formation novel cationic alkenyl complex [LAl-C(Et)═CH(Et)]+[B(C6F5)4]- (7) hydroalumination between Al-H cation 3-hexyne. Similarly, an unsymmetric internal alkyne 1-phenyl-1-propyne occurs regioselectively, leading [LAl-C(Me)═CH(Ph)]+[B(C6F5)4]- (8). unique isolated well by 1-D 2-D further act as catalytically active species carry forward pathway.

Language: Английский

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N^Nvs.N^E (E = S or Se) coordination behavior of imino-phosphanamidinate chalcogenide ligands towards aluminum alkyls: efficient hydroboration catalysis of nitriles, alkynes, and alkenes

Dalton Transactions, Journal Year: 2023, Volume and Issue: 52(14), P. 4481 - 4493

Published: Jan. 1, 2023

The synthesis, characterization, and catalytic application of six aluminum alkyl complexes supported by various imino-phosphanamidinate chalcogenide ligands are described. Six different unsymmetrical [NHIRP(Ph)(E)NH-Dipp] [R = 2,6-diisopropylphenyl (Dipp), E S (2a-H), Se (2b-H); R mesityl (Mes), (3a-H), (3b-H); tert-butyl (tBu), (4a-H), (4b-H)] were prepared the oxidation respective imino-phosphanamide (1a, 1b 1c) with elemental chalcogen atoms (S Se). general formulae [κ2NN-{NHIRP(Ph)(E)N-Dipp}AlMe2] Dipp, (5a), (5b); Mes, (6a), (6b)] or [κ2NE-{NHIRP(Ph)(E)N-Dipp}AlMe2] tBu, (7a), (7b)] synthesized in good yields from reaction suitable protic (2a,b-H-4a,b-H) trimethylaluminum a 1 : molar ratio toluene at room temperature. All well characterized multi-nuclear NMR spectroscopy, solid-state structures 2a,b-H-4a,b-H, 5a,b-6a,b 7b established single crystal X-ray diffraction analysis. 5a,b-7a,b tested as catalysts for hydroboration nitriles, alkynes, alkenes under mild conditions. reactions accomplished complex 5b temperature solvent-free conditions to afford high yield corresponding N,N-diborylamines, vinylboranes boronate esters, respectively.

Language: Английский

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Metal/Non‐Metal Catalyzed Activation of Organic Nitriles

The Chemical Record, Journal Year: 2022, Volume and Issue: 22(12)

Published: Sept. 20, 2022

Abstract Nitrile activation is a prominent topic in recent developments chemistry, especially organic, inorganic, biological as well the natural synthesis of products and pharmaceutical industry. The nitriles using both metal non‐metal precursors has attracted several researchers, who are exploring newer ways to synthesize novel compounds. can be achieved by combining various catalytic double hydroelementation reactions, such hydrosilylation, hydroboration, hydrogenation organonitriles silanes, pinacolborane, other sources hydrogen. These methodologies have garnered considerable attention since they effective reduction organonitriles, whose end extensively applied synthetic organic chemistry. In this review, we summarize development selective hydroborylation, dihydroborysilylation, their reaction mechanisms role complexes cycles. This review article explains toward into corresponding amines.

Language: Английский

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Aluminium‐Catalyzed Selective Hydroboration of Esters and Epoxides to Alcohols: C−O Bond Activation

Chemistry - A European Journal, Journal Year: 2022, Volume and Issue: 29(4)

Published: Oct. 13, 2022

In this work, the molecular aluminium dihydride complex bearing an N, N'-chelated conjugated bis-guanidinate (CBG) ligand is used as a catalyst for reducing wide range of aryl and alkyl esters with good tolerance alkene (C=C), alkyne (C≡C), halides (Cl, Br, I F), nitrile (C≡N), nitro (NO2 ) functionalities. Further, we investigated catalytic application in C-O bond cleavage epoxides into corresponding branched Markovnikov ring-opening products. addition, chemoselective intermolecular reduction over other reducible functional groups, such amides alkenes, has been established. Intermediates are isolated characterized by NMR HRMS studies, which confirm probable cycles hydroboration epoxides.

Language: Английский

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