First-Row d-Block Element-Catalyzed Carbon–Boron Bond Formation and Related Processes

Chemical Reviews, Journal Year: 2021, Volume and Issue: 121(21), P. 13238 - 13341

Published: Oct. 7, 2021

Organoboron reagents represent a unique class of compounds because their utility in modern synthetic organic chemistry, often affording unprecedented reactivity. The transformation the carbon–boron bond into carbon–X (X = C, N, and O) stereocontrolled fashion has become invaluable medicinal agrochemistry, natural products chemistry as well materials science. Over past decade, first-row d-block transition metals have increasingly widely used catalysts for formation bond, traditionally catalyzed by expensive precious metals. This recent focus on alternative enabled growth fundamental methods organoboron chemistry. review surveys current state-of-the-art use element-based bonds.

Language: Английский

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Nickel Chain-Walking Catalysis: A Journey to Migratory Carboboration of Alkenes

Accounts of Chemical Research, Journal Year: 2023, Volume and Issue: 56(22), P. 3246 - 3259

Published: Nov. 1, 2023

ConspectusChain-walking offers extensive opportunities for innovating synthetic methods that involve constructing chemical bonds at unconventional sites. This approach provides previously inaccessible retrosynthetic disconnections in organic synthesis. Through chain-walking, transition metal-catalyzed alkene difunctionalization reactions can take place a 1,n-addition (n ≠ 2) mode. Unlike classical 1,2-regioselective reactions, there remains scarcity of reports regarding migratory patterns. Moreover, the range olefins utilized these studies is quite limited.About five years ago, our research group embarked on project aimed developing valuable alkenes through chain-walking. Our focus was carboboration utilizing nickel catalysis. The reaction commences with insertion an olefin into Ni-Bpin species. Subsequently, thermodynamically stable alkyl complex generated chain-walking process. then couples carbon-based electrophile, leading to formation alkylboron compound. It worth highlighting success transformations relies significantly utilization bisnitrogen-based ligand and LiOMe as B2pin2 activator. Synthetically, establish robust platform rapid efficient synthesis wide structurally diverse organoboron compounds, which are not facially accessed by conventional methods. incorporation versatile boron introduces wealth possibilities subsequent diversifications, enhancing value resulting products allowing creation broader derivatives applications.This Account comprehensive overview efforts advancements field unactivated using We begin outlining development series 1,1-regioselective terminal alkenes. A significant placed initial integration boronate, only triggers metal species but also exerts control over remote stereochemistry involving substituted methylenecyclohexenes. Continuing exploration, remarkable achieved 1,3-regio- cis-stereoselectivity when dealing cyclic Remarkably, catalysis enables heterocyclic be viable coupling partners within transformations. it grants us ability achieve regioselectivity cyclohexenes unattainable, thus expanding horizons regiochemical reactions. Lastly, we present evolution ligand-modulated regiodivergent allylarenes. By gaining insights underlying mechanisms driving regiodivergence, lay strong foundation tackling challenges related selecting specific sites especially multiple factors. anticipate findings, coupled mechanistic we've gained, will advance realm contribute understanding selectivity this nature. advancement catalyze intricate functional molecules, contributing compounds chemistry.

Language: Английский

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The Impact of Boron Hybridisation on Photocatalytic Processes

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(38)

Published: June 24, 2022

Recently the fruitful merger of organoboron chemistry and photocatalysis has come to forefront organic synthesis, resulting in development new technologies access complex (non)borylated frameworks. Central success this combination is control boron hybridisation. Contingent on photoactivation mode, as its neutral planar form or tetrahedral boronate can be used regulate reactivity. This Minireview highlights current state art photocatalytic processes utilising compounds, paying particular attention role hybridisation for target transformation.

Language: Английский

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Copper-Catalyzed Stereospecific Transformations of Alkylboronic Esters

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(26), P. 11546 - 11552

Published: June 23, 2022

Copper-catalyzed stereospecific cross-couplings of boronic esters are reported. Boron "ate" complexes derived from pinacol and tert-butyl lithium undergo transmetalation to copper cyanide, followed by coupling with alkynyl bromides, allyl halides, propargylic β-haloenones, hydroxylamine esters, acyl chlorides. Through this simple transformation, commercially available inexpensive compounds can be employed convert primary secondary alkylboronic a wide array synthetically useful compounds.

Language: Английский

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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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Nickel-Catalyzed Regio- and Enantioselective Borylative Coupling of Terminal Alkenes with Alkyl Halides Enabled by an Anionic Bisoxazoline Ligand

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(25), P. 13603 - 13614

Published: June 6, 2023

Chiral boronic esters are a class of versatile building blocks. We describe herein an asymmetric nickel-catalyzed borylative coupling terminal alkenes with nonactivated alkyl halides. The success this reaction is ascribed to the application chiral anionic bisoxazoline ligand. This study provides three-component strategy access α- and β-stereogenic from easily accessible starting materials. protocol characterized by mild conditions, wide substrate scope high regio- enantioselectivity. also showcase value method in simplifying synthesis several drug molecules. Mechanistic studies suggest that generation enantioenriched bearing α-stereogenic center results stereoconvergent process, while enantioselectivity-controlling step β-stereocenter switched olefin migratory insertion due coordination ester group.

Language: Английский

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Photoinduced Selective B–H Activation of nido-Carboranes

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(11), P. 7791 - 7802

Published: March 10, 2024

The development of new synthetic methods for B–H bond activation has been an important research area in boron cluster chemistry, which may provide opportunities to broaden the application scope clusters. Herein, we present a reaction strategy direct site-selective functionalization nido-carboranes initiated by photoinduced cage via noncovalent cage···π interaction. As result, nido-carborane radical is generated through single electron transfer from 3D 2D photocatalyst upon irradiation with green light. resulting transient could be directly probed advanced time-resolved EPR technique. In air, subsequent transformations active have led efficient and selective B–N, B–S, B–Se couplings presence N-heterocycles, imines, thioethers, thioamides, selenium ethers. This protocol also facilitates both late-stage modification drugs synthesis nido-carborane-based drug candidates neutron capture therapy (BNCT).

Language: Английский

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Enantioselective synthesis of multifunctional alkylboronates via N-heterocyclic carbene–nickel-catalysed carboboration of alkenes

Nature Synthesis, Journal Year: 2024, Volume and Issue: 3(5), P. 633 - 642

Published: March 7, 2024

Language: Английский

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Copper- and Palladium-Cocatalyzed Chemo-, Regio-, Stereo-, and Atroposelective Arylboration of 1,3-Enynes

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(15), P. 11318 - 11331

Published: July 15, 2024

Catalytic enantioselective borylation reactions of unsaturated bonds as powerful tools for the synthesis diverse chiral organoboron compounds have gained much attention and wide applications in various fields. However, atroposelective arylboration reaction with carbon–carbon triple 1,3-enynes to obtain axially 1,3-dienylboronates remains an elusive significant challenge. Hence, we develop a cooperative copper- palladium-catalyzed assemble plentiful function enriched single step from easily available 1,3-enynes, B2pin2, aryl bromides high levels chemo-, regio-, stereo-, atroposelectivity. The mild conditions lead good functional group tolerance, which is proven by broad substrate scope late-stage functionalizations bioactive or drug molecules. Moreover, can be scaled up, series further transformations achieved. It worth emphasizing that several olefin catalysts ligands axial chirality also synthesized through corresponding elaborations such products, explains transformative ability application potential 1,3-dienylboronates. mechanism experiment density theory (DFT) calculations revealed process copper palladium catalysis, indicating chemoselectivity regioselectivity boration are determined enyne insertion on copper, atroposelectivity controlled reductive elimination center. Meanwhile, calculation demonstrated distinct interactions between P═O C═O groups Pd Bpin center key transition state formation products varying configurations while employing identical configuration ligands.

Language: Английский

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Cobalt‐Catalyzed Asymmetric Sequential Hydroboration/Isomerization/Hydroboration of 2‐Aryl Vinylcyclopropanes

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(30)

Published: May 24, 2022

A cobalt-catalyzed asymmetric sequential hydroboration/isomerization/hydroboration of 2-aryl vinylcyclopropanes was for the first time reported preparation valuable chiral 1,5-bis(boronates) in good yields with excellent enantioselectivity via isomerization/hydroboration a trisubstituted alkene intermediate. The reaction carried out smoothly and this protocol used syntheses (-)-preclamol gram-scale. two primary C(sp3) -B bonds could be distinguished iterative Suzuki-Miyaura cross-coupling reaction, delivering 1,2,5-triaryl alkanes enantioselectivity. Based on experimental computational studies, cobalt-hydride species proposed as active intermediate hydroboration, isomerization, second hydroboration reactions.

Language: Английский

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