Boryl radical-mediated halogen-atom transfer enables arylation of alkyl halides with electrophilic and nucleophilic coupling partners

Nature Synthesis, Journal Year: 2024, Volume and Issue: 3(10), P. 1221 - 1230

Published: July 1, 2024

Language: Английский

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A Radical Strategy for the Alkylation of Amides with Alkyl Halides by Merging Boryl Radical-Mediated Halogen-Atom Transfer and Copper Catalysis

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(32), P. 22424 - 22430

Published: Aug. 1, 2024

Amide alkylation is a fundamental process in organic chemistry. However, the low nucleophilicity of amides means that divergent coupling with alkyl electrophiles often not achievable. To circumvent this reactivity challenge, individual amine synthesis followed by amidation standard agents generally required. Herein, we demonstrate radical solution to challenge using an amine–borane complex and copper catalysis under oxidative conditions. While borohydride reagents are used as reducing ionic chemistry, their conversion into amine-ligated boryl radicals diverts toward halogen-atom transfer. This enables halides corresponding for amide functionalization via catalysis. The applicable N-alkylation primary employing unactivated iodides bromides, it was also showcased late-state both amide- halide-containing drugs.

Language: Английский

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Photocatalytic Direct Borylation of Benzothiazole Heterocycles via a Triplet Activation Strategy

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 11, 2025

Boron compounds are widely employed in organic chemistry, pharmaceuticals, and materials science. Among them, borylated heterocycles serve as versatile synthons for the construction of new C-C or C-heteroatom bonds via coupling radical processes. Such methods direct C-H borylation reactions high synthetic value to reduce number steps amount waste improve efficiency. Despite significant advances, remains an ongoing challenge with great potential applications chemical synthesis. Herein, we describe a photocatalytic reaction five-membered ring by employing stable N-heterocyclic carbene borane borylating reagent photoredox catalyst. Under green mild conditions, was achieved on series benzo-fused heterocyclic compounds. Further studies demonstrate utility this approach pharmaceutical agrochemical research.

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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Halogen Atom Transfer-Induced Homolysis of C–F Bonds by the Excited-State Boryl Radical

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(33), P. 22874 - 22880

Published: Aug. 2, 2024

A novel reactivity toward C-F bond functionalization has been developed, which could be designated as fluorine atom transfer (FAT). photoexcited state of an

Language: Английский

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Boryls, their compounds and reactivity: a structure and bonding perspective

Chemical Science, Journal Year: 2024, Volume and Issue: 15(9), P. 3060 - 3070

Published: Jan. 1, 2024

Boryls and their compounds are important due to diverse range of applications in the fields materials science catalysis. They an integral part boron chemistry, which has attracted tremendous research interest over past few decades. In this perspective, we provide in-depth analysis reaction chemistry boryl from a structure bonding perspective. We discuss reactivity boryls various transition metal complexes diborane(4) towards different substrate molecules, with focus on nucleophilic electrophilic properties processes. Additionally, briefly radicals. Our sheds new light unique potential for catalytic applications.

Language: Английский

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Unified Approach to Deamination and Deoxygenation Through Isonitrile Hydrodecyanation: A Combined Experimental and Computational Investigation

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(25)

Published: April 15, 2024

Herein, we describe a general hydrodefunctionalization protocol of alcohols and amines through common isonitrile intermediate. To cleave the relatively inert C-NC bond, leveraged dual hydrogen atom transfer (HAT) photoredox catalysis to generate nucleophilic boryl radical, which readily forms an imidoyl radical intermediate from isonitrile. Rapid β-scission then accomplishes defunctionalization. This method has been applied both amine alcohol-containing pharmaceuticals, natural products, biomolecules. We extended this approach reduction carbonyls olefins their saturated counterparts, as well hydrodecyanation alkyl nitriles. Both experimental computational studies demonstrate facile reconcile differences in reactivity between nitriles isonitriles within our protocol.

Language: Английский

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Electrochemical halogen-atom transfer alkylation via α-aminoalkyl radical activation of alkyl iodides

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Oct. 26, 2023

Abstract Alkyl halides, widely recognized as important building blocks and reagents in organic synthesis, can serve versatile alkyl radical precursors radical-based transformations. However, generating radicals directly from unactivated halides under mild conditions remains a challenge due to their extremely low reduction potentials. To address this issue, α-aminoalkyl were employed efficient halogen-atom transfer (XAT) the photoredox activation of halides. Here, we report an effective electrooxidation strategy for iodides via electrochemical ( e -XAT) process conditions. The generated by anodic oxidation are demonstrated be XAT these This facile electricity-driven obviates need sacrificial anodes external chemical oxidants. method successfully applies wide variety iodides, including primary, secondary, tertiary, well structurally diverse olefins, exhibiting excellent functional group tolerance. Moreover, further demonstrate utility rapidly functionalizing complex molecules biomolecules.

Language: Английский

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Photocatalytic Boryl Radicals Triggered Sequential B─N/C─N Bond Formation to Assemble Boron‐Handled Pyrazoles

Advanced Science, Journal Year: 2023, Volume and Issue: 11(3)

Published: Nov. 29, 2023

Abstract Vinyldiazo compounds are one of the most important synthons in construction a cyclic ring. Most photochemical transformations vinyldiazo mainly focusing on utilization their C═C bond site, while reactions taking place at terminal nitrogen atom largely unexplored. Herein, photocatalytic cascade radical cyclization LBRs with reagents through sequential B─N/C─N formation is described. The reaction starts addition (Lewis base–boryl radicals) diazo followed by intramolecular to access wide range boron‐handled pyrazoles good excellent yields. Control experiments, together detailed mechanism studies well explain observed reactivity. Further demonstrate utility this approach for applications pharmaceutical and agrochemical research.

Language: Английский

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Photoinduced Intermolecular Radical Hydroalkylation of Olefins via Ligated Boryl Radicals-Mediated Halogen Atom Transfer

Organic Letters, Journal Year: 2024, Volume and Issue: 26(27), P. 5839 - 5843

Published: July 1, 2024

Light-mediated Halogen-Atom Transfer (XAT) has become a significant methodology in contemporary synthesis. Unlike α-aminoalkyl and silyl radicals, ligated boryl radicals (LBRs) have not been extensively explored as halogen atom abstractors. In this study, we introduce NHC-ligated boranes optimal radical chain carriers for the intermolecular reductive hydroalkylation hydroarylation of electron-deficient olefins by using direct UV-A light irradiation. DFT analysis allowed us to rationalize critical role NHC ligand facilitating efficient propagation.

Language: Английский

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