Methodologies and Strategies for Selective Borylation of C–Het and C–C Bonds

Chemical Reviews, Journal Year: 2020, Volume and Issue: 120(15), P. 7348 - 7398

Published: June 29, 2020

Organoborons have emerged as versatile building blocks in organic synthesis to achieve molecular diversity and carboxylic acid bioisosteres with broad applicability drug discovery. Traditionally, these compounds are prepared by the substitution of Grignard/lithium reagents electrophilic boron species Brown hydroboration. Recent developments provided new routes for efficient preparation organoborons applying reactions using chemical feedstocks leaving groups. As compared previous methods that used halides (I, Br, Cl), direct borylation less reactive C–Het C–C bonds has become highly important get efficiency functional-group compatibility. This Review aims provide a comprehensive overview this topic, including (1) C–F bond borylation, (2) C–O (3) C–S (4) C–N (5) borylation. Considerable attention is given strategies mechanisms involved. We expect will inspire chemists discover more transformations expand field.

Language: Английский

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Photoinduced Borylation for the Synthesis of Organoboron Compounds

Chemical Reviews, Journal Year: 2021, Volume and Issue: 121(7), P. 3561 - 3597

Published: Feb. 17, 2021

Organoboron compounds have important synthetic value and can be applied in numerous transformations. The development of practical convenient ways to synthesize boronate esters has thus attracted significant interest. Photoinduced borylations originated from stoichiometric reactions alkanes arenes with well-defined metal–boryl complexes. Now, photoredox-initiated borylations, catalyzed by either transition metal or organic photocatalysts, photochemical high efficiency become a burgeoning area research. In this Focus Review, we summarize research on photoinduced especially emphasizing recent developments trends. This includes the borylation arenes, alkanes, aryl/alkyl halides, activated carboxylic acids, amines, alcohols, so based catalysis, metal-free organocatalysis, direct activation. We focus reaction mechanisms involving single-electron transfer, triplet-energy other radical processes.

Language: Английский

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Recent progress on selective deconstructive modes of halodifluoromethyl and trifluoromethyl-containing reagents

Chemical Society Reviews, Journal Year: 2020, Volume and Issue: 49(24), P. 9197 - 9219

Published: Jan. 1, 2020

Halodifluoromethyl and trifluoromethyl-containing compounds can act various rolesviaselective cleavage modes to access more valuable fluorinated or nonfluorinated molecules.

Language: Английский

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Recent advance in the C–F bond functionalization of trifluoromethyl-containing compounds

Organic Chemistry Frontiers, Journal Year: 2021, Volume and Issue: 8(14), P. 3915 - 3942

Published: Jan. 1, 2021

The C–F bond is the strongest single in organic compounds.

Language: Английский

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A general electron donor–acceptor complex for photoactivation of arenes via thianthrenation

Chemical Science, Journal Year: 2022, Volume and Issue: 13(19), P. 5659 - 5666

Published: Jan. 1, 2022

General photoactivation of EDA complexes between arylsulfonium salts and 1,4-diazabicyclo[2.2.2]octane was discovered. This practical mode enables the generation aryl radicals for C–H functionalization arenes.

Language: Английский

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Advances in chemistry of N-heterocyclic carbene boryl radicals

Chemical Society Reviews, Journal Year: 2021, Volume and Issue: 50(16), P. 8995 - 9021

Published: Jan. 1, 2021

This review focuses on synthesis and reactions of boryl radicals ligated by N-heterocyclic carbenes.

Language: Английский

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Lewis Base–Boryl Radicals Enabled Borylation Reactions and Selective Activation of Carbon–Heteroatom Bonds

Accounts of Chemical Research, Journal Year: 2022, Volume and Issue: 56(2), P. 169 - 186

Published: Dec. 26, 2022

ConspectusThe past decades have witnessed tremendous progress on radical reactions. However, in comparison with carbon, nitrogen, oxygen, and other main group element centered radicals, the synthetic chemistry of boron radicals was less studied, mainly due to high electron-deficiency instability such 3-center-5-electron species. In 1980s, Roberts co-workers found that coordination a Lewis base (amines or phosphines) center could form 4-center-7-electron boryl (Lewis base-boryl LBRs) are be more stable. only limited applications were developed. 2008, Curran achieved breakthrough discovery N-heterocyclic carbene (NHC) which enable range reduction polymerization Despite these exciting findings, powerful valuable LBRs would expected, given structures reactivities easily modulated, provide ample opportunities discover new this Account, summary our key contributions LBR-enabled borylation reactions selective activation inert carbon-heteroatom bonds will presented.Organoboron compounds shown versatile chemical society, their syntheses rely principally ionic The development mechanistically different allows synthesizing products inaccessible by traditional methods. For purpose, we progressively developed series NHC-boryl mediated chemo-, regio-, stereoselective alkenes alkynes, wide variety structurally diverse organoboron molecules successfully prepared. utility borylated also demonstrated. Furthermore, disclosed photoredox protocol for oxidative generation enabled useful defluoroborylation arylboration reactions.Selective bond is an ideal way convert simple starting materials value-added products, while cleavage bonds, particular chemoselectivity control when multiple identical present similar environments, remains long-standing challenge. We envisaged finely tuning properties might solution address Recently, 4-dimethylaminopyridine (DMAP)-boryl promoted sequential C-F functionalization trifluoroacetic acid derivatives, α-C-F selectively snipped via spin-center shift mechanism. This strategy enables facile conversion abundantly available highly mono- difluorinated molecules. Encouraged finding, further three-step sequence construct all-carbon quaternary centers from trichloromethyl groups, where three C-Cl cleaved rational choice suitable precursors each step. dehydroxylative alkylation α-hydroxy carboxylic derivatives achieved, allowing efficient some biomass platform value products.

Language: Английский

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Decatungstate-photocatalyzed direct acylation of N-heterocycles with aldehydes

Green Chemistry, Journal Year: 2024, Volume and Issue: 26(12), P. 7331 - 7336

Published: Jan. 1, 2024

A novel photocatalytic acylation strategy was developed harnessing tetrabutylammonium decatungstate (TBADT) as a hydrogen atom transfer (HAT) photocatalyst to facilitate the direct coupling of aldehydes with N-heterocycles at ambient temperature.

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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Hydroalkylation of Unactivated Olefins via Visible-Light-Driven Dual Hydrogen Atom Transfer Catalysis

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(29), P. 11251 - 11261

Published: July 16, 2021

Radical hydroalkylation of olefins enabled by hydrogen atom transfer (HAT) catalysis represents a straightforward means to access C(sp3)-rich molecules from abundant feedstock chemicals without the need for prefunctionalization. While Giese-type activated initiated HAT hydridic carbon-hydrogen bonds is well-precedented, unactivated in similar fashion remains elusive, primarily owing lack general methods overcome inherent polarity-mismatch this scenario. Here, we report use visible-light-driven dual achieve goal, where catalytic amounts an amine-borane and situ generated thiol were utilized as abstractor donor, respectively. The reaction completely atom-economical exhibits broad scope. Experimental computational studies support proposed mechanism suggest that hydrogen-bonding between substrates beneficial improving efficiency.

Language: Английский

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