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

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(14)

Published: Feb. 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.

Language: Английский

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Diborodichloromethane as Versatile Reagent for Chemodivergent Synthesis of gem‐Diborylalkanes

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 63(3)

Published: Dec. 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

Language: Английский

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

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(4), P. 2305 - 2314

Published: Jan. 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.

Language: Английский

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

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(23), P. 15850 - 15859

Published: May 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

Language: 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, Journal Year: 2024, Volume and Issue: 63(25)

Published: April 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.

Language: Английский

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

Chinese Journal of Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 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.

Language: Английский

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Boron Ylide Enables Stereoselective Construction of gem‐Diborylcyclopropanes

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 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.

Language: Английский

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Diverse Synthesis of (Thio)ethers and (Thio)esters Using Halodiborylmethane as a Transformable C₁ Building Block

Organic Letters, Journal Year: 2024, Volume and Issue: 26(33), P. 7010 - 7014

Published: Aug. 8, 2024

The development of effective strategies to forge C–O and C–S bonds in diverse chemical spaces is considerable interest synthetic organic chemistry. Herein we report a versatile approach for the modular synthesis structurally (thio)ethers (thio)esters via homologative coupling α-halodiborylmethane followed by transformation introduced diborylmethyl group. This method accommodates wide array oxygen- sulfur-containing molecules, including biologically active compounds. initial exhibits broad substrate scope, while subsequent diversification moiety enables access various structural motifs through deborylative alkylation, Zweifel olefination, boron-Wittig reaction. protocol efficiently generates diversely functionalized (thio)esters, expanding toolkit accessing relevant scaffolds.

Language: Английский

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Anion-Mediated, Stereospecific Synthesis of Secondary and Tertiary Cyclopropylboronates from Chiral Epoxides and gem-Diborylalkanes

Organic Letters, Journal Year: 2023, Volume and Issue: 25(22), P. 4130 - 4134

Published: May 25, 2023

We report a transition-metal-free deborylative cyclization approach to synthesize enantioenriched secondary and tertiary cyclopropylboronates using γ-phosphate-containing gem-diborylalkanes derived from chiral epoxides gem-diborylalkanes. Our method enables the synthesis of broad range in good yields with excellent stereospecificity. demonstrate versatility our by performing gram-scale reaction. also show that can be transformed into wide array cyclopropane derivatives stereospecific boron-group transformation.

Language: Английский

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Construction of α-Halogenated Boronic Esters via Visible Light-Induced C–H Bromination

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(19), P. 14246 - 14254

Published: Sept. 21, 2023

α-Halogenated boronic esters are versatile building blocks that can be diversified into a wide variety of polyfunctionalized molecules. However, their synthetic potential has been hampered by limited preparation methods. Herein, we report visible light-induced C-H bromination reaction readily available benzyl esters. This method features high yields, mild conditions, simple operation, and good functional group tolerance. The analogous chlorides iodides accessed via Finkelstein reaction. Synthesis halogenated geminal diborons also demonstrated.

Language: Английский

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