First-Row d-Block Element-Catalyzed Carbon–Boron Bond Formation and Related Processes

Chemical Reviews, Journal Year: 2021, Volume and Issue: 121(21), P. 13238 - 13341

Published: Oct. 7, 2021

Organoboron reagents represent a unique class of compounds because their utility in modern synthetic organic chemistry, often affording unprecedented reactivity. The transformation the carbon–boron bond into carbon–X (X = C, N, and O) stereocontrolled fashion has become invaluable medicinal agrochemistry, natural products chemistry as well materials science. Over past decade, first-row d-block transition metals have increasingly widely used catalysts for formation bond, traditionally catalyzed by expensive precious metals. This recent focus on alternative enabled growth fundamental methods organoboron chemistry. review surveys current state-of-the-art use element-based bonds.

Language: Английский

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Photoredox-Catalyzed Intermolecular Remote C–H and C–C Vinylation via Iminyl Radicals

Organic Letters, Journal Year: 2018, Volume and Issue: 20(17), P. 5523 - 5527

Published: Aug. 23, 2018

A unified strategy for intermolecular remote C(sp3)–H and C–C vinylation of O-acyl oximes with vinyl boronic acids has been achieved. This is enabled by photoreductive generation iminyl radicals from under irradiation visible light. The translocated carbon-centered radicals, which are generated the through 1,5-hydrogen atom transfer or cleavage, can be vinylated acids. opens up a new approach to functionalization via cleavage provides an efficient versatile solution synthesis γ-vinylation ketones nitriles.

Language: Английский

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

Tetrahedron Letters, Journal Year: 2018, Volume and Issue: 59(22), P. 2128 - 2140

Published: April 24, 2018

Language: Английский

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Highly tunable multi-borylation of gem-difluoroalkenes via copper catalysis

Nature Catalysis, Journal Year: 2018, Volume and Issue: 1(11), P. 860 - 869

Published: Oct. 26, 2018

Language: Английский

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

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 57(39), P. 12930 - 12934

Published: July 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.

Language: Английский

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Catalytic Chemo- and Enantioselective Transformations of gem-Diborylalkanes and (Diborylmethyl)metallic Species

Accounts of Chemical Research, Journal Year: 2021, Volume and Issue: 54(20), P. 3917 - 3929

Published: Oct. 6, 2021

ConspectusChemo- and stereoselective transformations of polyborylalkanes are powerful efficient methods to access optically active molecules with greater complexity diversity through programmed synthetic design. Among the various polyborylalkanes, gem-diborylalkanes have attracted much attention in organic chemistry as versatile handles. The notable advantage lies their ability generate two key intermediates, α-borylalkyl anions (gem-diborylalkyl) anions. These different intermediates can be applied enantioselective reactions rapidly a diverse set enantioenriched organoboron compounds, which further manipulated chiral molecule libraries via stereospecific C(sp3)–B bond transformations.In this Account, we summarize our recent contributions development catalytic chemo- using nucleophiles, categorized follows: (1) copper-catalyzed coupling electrophiles (2) design synthesis (diborylmethyl)metallic species applications reactions. Since Shibata Endo reported Pd-catalyzed chemoselective Suzuki–Miyaura cross-coupling organohalides 2014, Morken Hall subsequently developed first analogous TADDOL-derived phosphoramidite supporting ligand palladium catalyst. This discovery sparked interest electrophiles. Our initial studies focused on generating (α-borylmethyl)copper by enantiotopic-group-selective transmetalation copper complexes aldimines ketimines afford syn-β-aminoboronate esters excellent enantio- diastereoselectivity. Moreover, allylation that proceeded reaction situ-generated (α-borylalkyl)copper allyl bromides. Mechanistic investigations revealed between complex occurred open transition state rather than closed state, thereby effectively species. We also utilized such (diborylmethyl)silanes (diborylmethyl)zinc halides succeeded developing aryl iodides benzylic 1,1-silylboronate esters, could used for consecutive molecules. In addition, synthesized time isolated (diborylmethyl)lithium zinc(II) utilization bearing center at β-position an iridium-catalyzed allylic substitution process. addition research efforts, include other groups. hope Account will draw community gem-diboryl compounds provide guiding principles future compounds.

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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Versatile cobalt-catalyzed regioselective chain-walking double hydroboration of 1,n-dienes to access gem-bis(boryl)alkanes

Nature Communications, Journal Year: 2020, Volume and Issue: 11(1)

Published: Feb. 7, 2020

Abstract Double hydroboration of dienes is the addition a hydrogen and boryl group to two double bonds diene molecule represents straightforward effective protocol prepare synthetically versatile bis(boryl)alkanes, provided that this reaction occurs selectively. However, can potentially yield several isomeric organoboron products, it still remains challenge control regioselectivity reaction, which allows selective production single product, in particular, for broad scope dienes. By employing readily available cobalt catalyst, here we show yields useful gem -bis(boryl)alkanes with excellent regioselectivity. In addition, encompasses wide range conjugated non-conjugated Furthermore, mechanistic studies indicate cobalt-catalyzed through boryl-directed chain-walking alkenylboronates generated from anti -Markovnikov 1,2-hydroboration 1,n-diene.

Language: Английский

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Visible-Light-Induced Radical Carbo-Cyclization/gem-Diborylation through Triplet Energy Transfer between a Gold Catalyst and Aryl Iodides

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(23), P. 10485 - 10493

Published: April 30, 2020

Geminal diboronates have attracted significant attention because of their unique structures and reactivity. However, benzofuran-, indole-, benzothiophene-based benzylic gem-diboronates, building blocks for biologically relevant compounds, are unknown. A promising protocol using visible light aryl iodides constructing valuable blocks, including via radical carbo-cyclization/gem-diborylation alkynes with a high functional group tolerance is presented. The utility these gem-diboronates has been demonstrated by 10 g scale conversion, versatile transformations, the synthesis approved drug scaffolds two drugs, even polymer synthesis. mechanistic investigation indicates that merging dinuclear gold catalyst (photoexcitation 315–400 nm UVA light) Na2CO3 directly responsible photosensitization 254 UV blue LED (410–490 nm, λmax = 465 nm) through an energy transfer (EnT) process, followed homolytic cleavage C–I bond in iodide substrates.

Language: Английский

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