Direct Synthesis of Multi(boronate) Esters from Alkenes and Alkynes via Hydroboration and Boration Reactions

ACS Catalysis, Journal Year: 2020, Volume and Issue: 11(1), P. 1 - 18

Published: Dec. 10, 2020

Multi(boronate) esters have been attracting increasing attention as versatile building blocks for the succinct and precise synthesis of complex molecules. However, there are a limited number efficient synthetic procedures available. In this respect, direct multiboration alkenes alkynes is undoubtedly an ideal route their synthesis. During past 30 years, catalytic systems based on transition-metals, organophosphines, bases, even catalyst-free systems, with heat or light irradiation straightforward preparation from developed. different numbers (up to 4) positional relationships adjacent boron moieties were obtained, which summarized discussed herein.

Language: Английский

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α-Borylalkyl radicals: their distinctive reactivity in modern organic synthesis

Chemical Communications, Journal Year: 2019, Volume and Issue: 56(1), P. 13 - 25

Published: Nov. 27, 2019

Organoborons are extremely important for synthetic organic chemistry; they can serve as advanced intermediates a variety of transformations. Such well-known transformation involves the loss boron moiety, creating alkyl radicals. Although these originally developed protocols radical generation remain in active use today, recent years their α-boryl carbon-centred radicals have been joined by new array strategies that offer unique reactivity to forge wider diversity organoborons often operate under mild and benign conditions. Herein, we will highlight stability α-borylalkyl remarkably advances order further utilise them C-C C-heteroatom bond formation. Their this purpose has reported over last decade an attempt guide community. Various transition-metal metal-free methods presented, more photoredox approaches discussed, mainly period 2009-2019.

Language: Английский

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Advances in transition metal-free deborylative transformations of gem-diborylalkanes

Chemical Communications, Journal Year: 2021, Volume and Issue: 57(36), P. 4346 - 4353

Published: Jan. 1, 2021

This article highlights recent advances on the base-promoted deborylative carbon–carbon and carbon–boron bond-forming reactions using gem-diborylalkanes as sources of α-borylcabanions.

Language: Английский

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α-Boryl Organometallic Reagents in Catalytic Asymmetric Synthesis

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(16), P. 10660 - 10680

Published: Aug. 12, 2021

Recent years have witnessed an increase in the popularity of α-boryl organometallic reagents as versatile nucleophiles asymmetric synthesis. These compounds been adopted chemo- and stereoselective coupling reactions with a number different electrophiles. The resulting enantioenriched boronic esters can be applied stereospecific carbon-carbon or carbon-heteroatom bond construction reactions, enabling two-step strategy for complex structures high efficiency functional group compatibility. Due to these reasons, tremendous effort has devoted preparation enantiomerically enriched development related racemic prochiral materials. In this review, we describe enantio- diastereoselective that involve starting materials products showcase their synthetic utility.

Language: Английский

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Photocatalyzed Borylcyclopropanation of Alkenes with a (Diborylmethyl)iodide Reagent

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(38)

Published: Aug. 2, 2023

Cyclopropane skeletons play a prominent role in the development of organic synthesis and pharmaceutical chemistry. Herein, we report design stable, multifunctional (diborylmethyl)iodide reagent (CHI(Bpin)2 ) for photoinduced cyclopropanation alkenes, providing an array 1,2-substituted cyclopropylboronates good yields. This α-haloboronic ester can be readily synthesized on multigram scale from commercially available starting materials. Furthermore, protocol displays high chemo- diastereoselectivity, excellent functional-group tolerance, allows late-stage borylcyclopropanation complex molecules. Mechanistic studies reveal that proceeds through radical addition/polar cyclization pathway mediated by photocatalyst fac-Ir(ppy)3 visible light.

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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A Boron–Boron Double Transborylation Strategy for the Synthesis of gem-Diborylalkanes

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(8), P. 4686 - 4691

Published: March 30, 2020

Olefin hydroboration reactions provide efficient access to synthetically versatile and easily handled organoboronic esters. In this study, we demonstrate that the commercially available organoborane reagent 9-borabicyclo[3.3.1]nonane (H-B-9-BBN) can serve as a catalyst for sequential double of alkynes using pinacolborane (HBpin). This strategy, which is effective wide range terminal alkynes, predicated upon key C(sp3)−B/B–H transborylation reaction. Transition-state thermodynamic parameters 10-boron-isotopic labeling experiments are indicative σ-bond metathesis exchange pathway.

Language: Английский

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Recent developments in the asymmetric synthesis and functionalization of symmetrical and unsymmetricalgem-diborylalkanes

Organic Chemistry Frontiers, Journal Year: 2021, Volume and Issue: 9(3), P. 838 - 852

Published: Nov. 16, 2021

gem -Diborylalkanes are an important class of organoboron compounds as they function a key building block in organic synthesis. This review summarizes recent developments the enantioselective synthesis -diborylalkanes and application asymmetric

Language: Английский

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One step synthesis of unsymmetrical 1,3-disubstituted BCP ketones via nickel/photoredox-catalyzed [1.1.1]propellane multicomponent dicarbofunctionalization

Chemical Science, Journal Year: 2022, Volume and Issue: 13(40), P. 11936 - 11942

Published: Jan. 1, 2022

Bicyclo[1.1.1]pentanes (BCPs), utilized as sp3-rich bioisosteres for tert-butyl- and aryl groups well internal alkynes, have gained considerable momentum in drug development programs. Although many elegant methods been developed to access BCP amines aryls efficiently, the used construct ketones directly are relatively underdeveloped. In particular, preparation of unsymmetrical 1,3-disubstituted-BCP remains challenging still requires multiple chemical steps. Herein, a single-step, multi-component approach versatile disubstituted via nickel/photoredox catalysis is reported. Importantly, installing boron group at carbon position adjacent structure bypasses limitation tertiary BF3K coupling partners, thus expanding scope this paradigm. Further transformation disubstituted-BCP into variety other derivatives demonstrates synthetic value method.

Language: Английский

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Stereodefined polymetalloid alkenes synthesis via stereoselective boron-masking of polyborylated alkenes

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

Published: April 11, 2023

Polyborylated-alkenes are valuable polymetalloid reagents in modern organic synthesis, providing access to a wide array of transformations, including the construction multiple C-C and C-heteroatom bonds. However, because they contain similar boryl groups, many times their transformation faces main challenge controlling chemo-, regio- stereoselectivity. One way overcome these limitations is by installing different boron groups that can provide an opportunity tune reactivity toward better Yet, preparation polyborylated-alkenes containing has been rare. Herein we report concise, highly site-selective, stereoselective boron-masking strategies polyborylated alkenes. This achieved designed trifluorination MIDA-ation reactions readily available starting Additionally, trifluoroborylated-alkenes undergo stereospecific interconversion Bdan-alkenes. These transition-metal free general efficient method for conversion alkenes 1,1-di-, 1,2-di-, 1,1,2-tris-(borylated) BF

Language: Английский

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