Electrooxidative Activation of B−B Bond in B₂cat₂: Access to gem‐Diborylalkanes via Paired Electrolysis

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(14)

Опубликована: Фев. 1, 2023

This report describes the unprecedented electrooxidation of a solvent (e.g., DMF)-ligated B2 cat2 complex, whereby solvent-stabilized boryl radical is formed via quasi-homolytic cleavage B-B bond in DMF-ligated cation. Cyclic voltammetry and density functional theory provide evidence to support this novel activation strategy. Furthermore, strategy for electrochemical gem-diborylation gem-bromides paired electrolysis developed first time, affording range versatile gem-diborylalkanes, which are widely used synthetic society. Notably, reaction approach scalable, transition-metal-free, requires no external activator.

Язык: Английский

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Diborodichloromethane as Versatile Reagent for Chemodivergent Synthesis of gem‐Diborylalkanes

Angewandte Chemie International Edition, Год журнала: 2023, Номер 63(3)

Опубликована: Дек. 8, 2023

Abstract The development of boron reagents is crucial for synthetic chemistry. Herein, we present a scalable and practical synthesis diborodichloromethane (DBDCM) through the reaction trichloromethyllithium with bis(pinacolato)diboron (B 2 pin ). resulting DBDCM reagent serves as basic unit construction various structurally diverse gem ‐diborylalkanes controllable C−Cl functionalizations. Moreover, have developed consecutive tetra‐functionalizations tertiary quaternary carbon containing molecules. use isotopically enriched 13 C‐chloroform 10 B enables C‐DBDCM B‐DBDCM reagents, which are beneficial convenient carbon‐13 boron‐10

Язык: Английский

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Ir-Catalyzed Regioselective Dihydroboration of Thioalkynes toward Gem-Diboryl Thioethers

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(4), С. 2305 - 2314

Опубликована: Янв. 19, 2023

While 1,1-diboryl (gem-diboryl) compounds are valuable synthetic building blocks, currently, related studies have mainly focused on those alkanes without a hetero functional group in the α-position. gem-Diboryl with an α-hetero substituent, though highly versatile, been limitedly accessible and thus rarely utilized. Herein, we developed first α-dihydroboration of heteroalkynes leading to efficient construction gem-diboryl, hetero-, tetra-substituted carbon centers. This straightforward, practical, mild, atom-economic reaction is attractive complement conventional multistep strategy relying deprotonation gem-diborylmethane by strong base. Specifically, [Ir(cod)(OMe)]2 was found be uniquely effective for this process thioalkynes, excellent α-regioselectivity when delivering two boryl groups, which remarkable view many competitive paths including monohydroboration, 1,2-dihydroboration, dehydrodiboration, triboration, tetraboration, etc. Control experiments combined DFT calculations suggested that involves sequential hydroboration events. The second requires higher energy barrier due severe steric repulsion generating congested α-sulfenyl gem-diboryl center, structural motif almost unknown before.

Язык: Английский

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Palladium‐Catalyzed Cascade Heck Coupling and Allylboration of Iododiboron Compounds via Diboryl Radicals

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(18)

Опубликована: Март 6, 2024

Geminal bis(boronates) are versatile synthetic building blocks in organic chemistry. The fact that they predominantly serve as nucleophiles the previous reports, however, has restrained their potential. Herein we disclose ambiphilic reactivity of α-halogenated geminal bis(boronates), which first catalytic utilization was accomplished by merging a formal Heck cross-coupling with highly diastereoselective allylboration aldehydes or imines, providing new avenue for rapid assembly polyfunctionalized boron-containing compounds. We demonstrated this cascade reaction is efficient and compatible various functional groups, wide range heterocycles. In contrast to classical Pd(0/II) scenario, mechanistic experiments DFT calculations have provided strong evidence cycle involving Pd(I)/diboryl carbon radical intermediates.

Язык: Английский

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Photogeneration of α-Bimetalloid Radicals via Selective Activation of Multifunctional C1 Units

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(23), С. 15850 - 15859

Опубликована: Май 28, 2024

Light-driven strategies that enable the chemoselective activation of a specific bond in multifunctional systems are comparatively underexplored comparison to transition-metal-based technologies, yet desirable when considering controlled exploration chemical space. With current drive discover next-generation therapeutics, reaction design enables strategic incorporation an sp3 carbon center, containing multiple synthetic handles for subsequent space would be highly enabling. Here, we describe photoactivation ambiphilic C1 units generate α-bimetalloid radicals using only Lewis base and light source directly activate C–I bond. Interception these transient with various SOMOphiles rapid synthesis organic scaffolds (B, Si, Ge) orthogonal activation. In-depth theoretical mechanistic studies reveal prominent role 2,6-lutidine forming photoactive charge transfer complex stabilizing situ generated iodine radicals, as well influential boron p-orbital activation/weakening This simple efficient methodology enabled expedient access functionalized 3D frameworks can further derivatized available technologies C–B C–Si

Язык: Английский

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PolyBorylated Alkenes as Energy‐Transfer Reactive Groups: Access to Multi‐Borylated Cyclobutanes Combined with Hydrogen Atom Transfer Event

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(25)

Опубликована: Апрель 11, 2024

Abstract While polyborylated alkenes are being recognized for their elevated status as highly valuable reagents in modern organic synthesis, allowing efficient access to a diverse array of transformations, including the formation C−C and C‐heteroatom bonds, potential energy‐transfer reactive groups has remained unexplored. Yet, this holds key generating elusive biradical species, which can be captured by olefins, thereby leading construction new highly‐borylated scaffolds. Herein, we report designed strategy photosensitized [2+2]‐cycloadditions poly‐borylated with various olefins enabling regioselective synthesis cyclobutane motifs, 1,1‐di‐, 1,1,2‐tri‐, 1,1,2,2‐tetra‐borylated cyclobutanes. In fact, these compounds belong family that presently lacks synthetic pathways. Interestingly, when α‐methylstyrene was used, reaction involves an interesting 1,5‐hydrogen atom transfer (HAT). Mechanistic deuterium‐labeling studies have provided insight into outcome process. addition, cyclobutanes then demonstrated useful selective oxidation processes resulting cyclobutanones γ‐lactones.

Язык: Английский

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Boron Ylide Enables Stereoselective Construction of gem‐Diborylcyclopropanes

Angewandte Chemie International Edition, Год журнала: 2024, Номер unknown

Опубликована: Сен. 20, 2024

Abstract The stereoselective cyclopropanation of olefins with “boron ylide” is disclosed for the first time, providing a modular strategy synthesis stereospecific diboryl‐functionalized cyclopropanes. chiral gem ‐diborylcyclopropanes are synthesized excellent enantioselectivity aid auxiliary. Based on powerful transformable ability boryl group, those challenging multi‐quaternary carbon centers in cyclopropane units have been facilely constructed stereoselectivity. Control experiments indicate that groups necessary both chemoselectivity and stereoselectivity control.

Язык: Английский

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Construction of 1,3‐Diboryl Allenes from gem‐Iododiboron Compounds via Intermolecular Boryl Group Transfer^†

Chinese Journal of Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Янв. 23, 2025

Comprehensive Summary Allenylboronates are valuable synthetic building blocks and have garnered significant interest. However, their 1,3‐diboyl substituted analogs not been reported. Herein, we disclosed a novel method for creating allenes from gem ‐iododiboron compounds alkynyl Grignard reagents. The starting materials initially converted into the corresponding propargylic ‐bis(boronates), which then undergo an intermolecular boryl group transfer to afford allenes, as confirmed by mechanistic studies. This features good tolerance steric hindrance is compatible with wide variety of functional groups.

Язык: Английский

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Stereoselective Access to Tetra‐ and Tri‐Substituted Fluoro‐ and Chloro‐Borylalkenes via Boron‐Wittig Reaction

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(41)

Опубликована: Авг. 23, 2022

Reported herein is the efficient synthesis of tetra- and tri-substituted (Z)-fluoro- (Z)-chloro-borylalkenes by Boron-Wittig reaction ketones aldehydes with bench-top stable halo-diborylmethanes. The substrate scope broad proceeds from a diverse range including biologically relevant molecules fluoro- or chloro-diborylmethanes, providing in good yields high stereoselectivity. utilities obtained are highlighted further modifications to afford fluoroalkene derivatives all-carbon substituted alkene.

Язык: Английский

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A General Method to Access Sterically Encumbered Geminal Bis(boronates) via Formal Umpolung Transformation of Terminal Diboron Compounds

Angewandte Chemie International Edition, Год журнала: 2023, Номер 63(4)

Опубликована: Дек. 8, 2023

Abstract General methods for the preparation of geminal bis(boronates) are great interest due to their widespread applications in organic synthesis. While terminal gem ‐diboron compounds readily accessible, construction sterically encumbered, internal analogues has remained a prominent challenge. Herein, we report formal umpolung strategy access these valuable building blocks. The available 1,1‐diborylalkanes were first converted into corresponding α‐halogenated derivatives, which then serve as electrophilic components, undergoing substitution with diverse array nucleophiles form series C−C, C−O, C−S, and C−N bonds. This protocol features good tolerance steric hindrance wide variety functional groups heterocycles. Notably, this can also be extended synthesis diaryl compounds, therefore providing general approach various types bis(boronates).

Язык: Английский

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