gem-Diborylalkanes: recent advances in their preparation, transformation and application

Organic & Biomolecular Chemistry, Год журнала: 2018, Номер 16(7), С. 1050 - 1064

Опубликована: Янв. 1, 2018

Recently,gem-diborylalkanes have attracted much attention as versatile building blocks and fundamental intermediates in organic synthesis, because they enable multiple C–C bond construction further transformation at C–B bonds.

Язык: Английский

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Synthesis and Reactivity of 1,1‐Diborylalkanes towards C–C Bond Formation and Related Mechanisms

Advanced Synthesis & Catalysis, Год журнала: 2017, Номер 360(7), С. 1306 - 1327

Опубликована: Дек. 6, 2017

Abstract gem ‐Diborylalkanes have emerged as efficient reagents for synthesizing organoboron compounds through selective C−C bond‐forming reactions. Activation of the 1,1‐diborylalkanes generates carbanions with enhanced stability that are able to react a series electrophiles, carbonyl compounds, imines and epoxides promote formation new bond. These sets reactions become general wide range substrates they can be understood by alternative mechanisms justify potential use these reagents. The C–C(B) bonds achieved chemo‐, diastereo‐ enantioselectivity, because nucleophilc α‐boryl or α‐diboryl attack in stereoselective manner, means catalyst involved. synthesis ‐diborylalkanes has also been promoted innovative methods facilitates access multiborylated different substituents properties. magnified image

Язык: Английский

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Geminal bis(boron) compounds: Their preparation and synthetic applications

Tetrahedron Letters, Год журнала: 2018, Номер 59(22), С. 2128 - 2140

Опубликована: Апрель 24, 2018

Язык: Английский

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

ACS Catalysis, Год журнала: 2020, Номер 11(1), С. 1 - 18

Опубликована: Дек. 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.

Язык: Английский

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Generation and Application of (Diborylmethyl)zinc(II) Species: Access to Enantioenriched gem‐Diborylalkanes by an Asymmetric Allylic Substitution

Angewandte Chemie International Edition, Год журнала: 2018, Номер 57(39), С. 12930 - 12934

Опубликована: Июль 2, 2018

We report the successful generation of (diborylmethyl)zinc(II) species by transmetallation beteween isolable (diborylmethyl)lithium and zinc(II) halide (X=Br, Cl) their application in synthesis enantioenriched gem-diborylalkanes bearing a stereogenic center at β-position diboryl groups an asymmetric allylic substitution reaction. The reaction has broad substrate scope, various can be obtained good yields with excellent enantioselectivity. Further elaboration provides access to diverse set valuable chiral building blocks.

Язык: Английский

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Design and Synthesis of WJ-Phos, and Application in Cu-Catalyzed Enantioselective Boroacylation of 1,1-Disubstituted Allenes

ACS Catalysis, Год журнала: 2019, Номер 9(8), С. 6890 - 6895

Опубликована: Июнь 28, 2019

The highly enantioselective copper-catalyzed three-component boroacylation of 1,1-disubstituted allenes is reported by using a class chiral ligands (WJ-Phos), delivering various functionalized organoboron compounds bearing an all-carbon stereocenter in moderate to good yields with high enantioselectivities. WJ-Phos ferrocene-derived sulfinamide phosphine ligand and can be easily synthesized gram-scale from readily available starting materials short steps. salient features this reaction include yields, enantioselectivities, synthesis, diverse synthetic transformations, the development new ligand.

Язык: Английский

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α-Boryl Organometallic Reagents in Catalytic Asymmetric Synthesis

ACS Catalysis, Год журнала: 2021, Номер 11(16), С. 10660 - 10680

Опубликована: Авг. 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.

Язык: Английский

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Copper-Catalyzed Enantiotopic-Group-Selective Allylation of gem-Diborylalkanes

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(2), С. 1069 - 1077

Опубликована: Янв. 4, 2021

We report a copper-catalyzed enatiotopic-group-selective allylation of gem-diborylalkanes with allyl bromides. The combination copper(I) bromide and H8-BINOL derived phosphoramidite ligand proved to be the most effective catalytic system provide various enantioenriched homoallylic boronate esters, containing boron-substituted stereogenic center that is solely from gem-diborylalkanes, in good yields high enantiomeric ratios under mild conditions. Experimental theoretical studies have been conducted elucidate reaction mechanism, revealing how transmetalation chiral copper complex occurs generate α-borylalkyl-copper species for first time. Additional synthetic applications synthesis building blocks are also included.

Язык: Английский

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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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Facile Access to Cyclopropylboronates via Stereospecific Deborylative Cyclization: A Leaving Group‐Assisted Activation of Geminal Diborons

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(21)

Опубликована: Март 24, 2023

Herein we reported a transition metal-free deborylative cyclization strategy, based on which two routes have been developed, generating racemic and enantioenriched cyclopropylboronates. The of geminal-bis(boronates) bearing leaving group was highly diastereoselective, tolerating few functional groups applicable to heterocycles. When optically active epoxides were used as the starting materials, cyclopropylboronates could be efficiently prepared with >99 % stereospecificity. Mechanistic studies showed that at γ-position played crucial role significantly promoted activation gem-diboron moiety.

Язык: Английский

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