Electrooxidative Activation of B−B Bond in B₂cat₂: Access to gem‐Diborylalkanes via Paired Electrolysis

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(14)

Published: Feb. 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.

Language: Английский

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Diastereo- and atroposelective synthesis of N-arylpyrroles enabled by light-induced phosphoric acid catalysis

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

Published: Aug. 9, 2023

The C-N axially chiral N-arylpyrrole motifs are privileged scaffolds in numerous biologically active molecules and natural products, as well ligands/catalysts. Asymmetric synthesis of N-arylpyrroles, however, is still challenging, the simultaneous creation contiguous axial central chirality remains unknown. Herein, a diastereo- atroposelective N-arylpyrroles enabled by light-induced phosphoric acid catalysis has been developed. key transformation one-pot, three-component oxo-diarylation reaction, which simultaneously creates quaternary stereogenic center. A broad range unactivated alkynes were readily employed reaction partner this transformation, products obtained good yields, with excellent enantioselectivities very diastereoselectivities. Notably, skeletons represent interesting structural that could be used ligands catalysts asymmetric catalysis.

Language: Английский

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Ir‐Catalyzed Enantioselective Synthesis of gem‐Diborylalkenes Enabled by 1,2‐Boron Shift

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(32)

Published: June 15, 2023

Abstract Asymmetric cross‐couplings based on 1,2‐carbon migration from B‐ate complexes have been developed efficiently to access valuable organoboronates. However, enantioselective reactions triggered by 1,2‐boron shift remained be unaddressed synthetic challenge. Here, Ir‐catalyzed asymmetric allylic alkylation enabled was developed. In this reaction, we disclosed that excellent enantioselectivities were achieved through an interesting dynamic kinetic resolution (DKR) process of carbonates at the elevated temperature. Notably, highly (bis‐boryl)alkenes array diversifications versatile molecules. Extensive experimental and computational studies conducted elucidate reaction mechanism DKR clarify origin enantioselectivities.

Language: Английский

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Ir-Catalyzed Regioselective Dihydroboration of Thioalkynes toward Gem-Diboryl Thioethers

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(4), P. 2305 - 2314

Published: Jan. 19, 2023

While 1,1-diboryl (gem-diboryl) compounds are valuable synthetic building blocks, currently, related studies have mainly focused on those alkanes without a hetero functional group in the α-position. gem-Diboryl with an α-hetero substituent, though highly versatile, been limitedly accessible and thus rarely utilized. Herein, we developed first α-dihydroboration of heteroalkynes leading to efficient construction gem-diboryl, hetero-, tetra-substituted carbon centers. This straightforward, practical, mild, atom-economic reaction is attractive complement conventional multistep strategy relying deprotonation gem-diborylmethane by strong base. Specifically, [Ir(cod)(OMe)]2 was found be uniquely effective for this process thioalkynes, excellent α-regioselectivity when delivering two boryl groups, which remarkable view many competitive paths including monohydroboration, 1,2-dihydroboration, dehydrodiboration, triboration, tetraboration, etc. Control experiments combined DFT calculations suggested that involves sequential hydroboration events. The second requires higher energy barrier due severe steric repulsion generating congested α-sulfenyl gem-diboryl center, structural motif almost unknown before.

Language: Английский

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Copper-catalysed asymmetric hydroboration of alkenes with 1,2-benzazaborines to access chiral naphthalene isosteres

Nature Chemistry, Journal Year: 2024, Volume and Issue: 16(8), P. 1312 - 1319

Published: April 8, 2024

Language: Английский

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Chemo-, regio- and stereoselective access to polysubstituted 1,3-dienes via Nickel-catalyzed four-component reactions

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: June 28, 2024

1,2-Difunctionalization of alkynes offers a straightforward approach to access polysubstituted alkenes. However, simultaneous multi-component cascade transformations including difunctionalization two with both syn- and anti-selectivity in one catalyst system is undeveloped proves be significant challenge. Herein, we report Nickel-catalyzed four-component reaction 1,3-dienes using terminal alkynes, aryl boroxines, perfluoroalkyl iodides, wherein the forms three new C-C bonds single vessel serve as modular strategy excellent chemoselectivity, good regioselectivity exclusive stereoselectivity. Control experiments reveal plausible mechanism DFT calculations explain cause for formation this unusual reaction. Furthermore, successfully incorporate biologically active units into 1,2,3,4-tetrasubstituted 1,3-dienes, which greatly increases diversity molecular scaffolds brings more potential values medicinal chemistry, synthetic utility our protocol further demonstrated by late-stage transformations.

Language: Английский

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Copper- and Palladium-Cocatalyzed Chemo-, Regio-, Stereo-, and Atroposelective Arylboration of 1,3-Enynes

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(15), P. 11318 - 11331

Published: July 15, 2024

Catalytic enantioselective borylation reactions of unsaturated bonds as powerful tools for the synthesis diverse chiral organoboron compounds have gained much attention and wide applications in various fields. However, atroposelective arylboration reaction with carbon–carbon triple 1,3-enynes to obtain axially 1,3-dienylboronates remains an elusive significant challenge. Hence, we develop a cooperative copper- palladium-catalyzed assemble plentiful function enriched single step from easily available 1,3-enynes, B2pin2, aryl bromides high levels chemo-, regio-, stereo-, atroposelectivity. The mild conditions lead good functional group tolerance, which is proven by broad substrate scope late-stage functionalizations bioactive or drug molecules. Moreover, can be scaled up, series further transformations achieved. It worth emphasizing that several olefin catalysts ligands axial chirality also synthesized through corresponding elaborations such products, explains transformative ability application potential 1,3-dienylboronates. mechanism experiment density theory (DFT) calculations revealed process copper palladium catalysis, indicating chemoselectivity regioselectivity boration are determined enyne insertion on copper, atroposelectivity controlled reductive elimination center. Meanwhile, calculation demonstrated distinct interactions between P═O C═O groups Pd Bpin center key transition state formation products varying configurations while employing identical configuration ligands.

Language: Английский

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Pathway-divergent coupling of 1,3-enynes with acrylates through cascade cobalt catalysis

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: April 23, 2024

Catalytic cascade transformations of simple starting materials into highly functionalized molecules bearing a stereochemically defined multisubstituted alkene, which are important in medicinal chemistry, natural product synthesis, and material science, high demand for organic synthesis. The development multiple reaction pathways accurately controlled by catalysts derived from different ligands is critical goal the field catalysis. Here we report cobalt-catalyzed strategy direct coupling inexpensive 1,3-enynes with two acrylates to construct diversity 1,3-dienes containing trisubstituted or tetrasubstituted olefin. Such reactions can proceed through three initiated oxidative cyclization achieve bond formation chemo-, regio- stereoselectivity precisely ligands, providing platform tandem carbon-carbon bond-forming reactions.

Language: Английский

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Enantioselective 1,4-Borylamination via Copper-Catalyzed Cascade Hydroborylation and Hydroamination of Arylidenecyclopropanes

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(47), P. 32283 - 32291

Published: Nov. 13, 2024

Compounds bearing both boryl and amino groups at distal positions are invaluable synthons for synthesizing pharmaceuticals, drug candidates, natural products, but their catalytic enantioselective synthesis remains rarely explored. We report the first 1,4-borylamination reaction through a copper-catalyzed cascade hydroborylation hydroamination of arylidenecyclopropanes. This combines four readily available components in highly chemo-, site-, fashion (>20:1 r.r. up to 99% ee), yielding diverse array synthetically valuable enantioenriched 4-amino alkylboronates. The versatile utility these products is highlighted by transformations wide applications pharmaceutical discovery. Preliminary mechanistic studies were conducted elucidate operative pathway, intermediates, origins its high chemo- site-selectivity.

Language: Английский

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Copper‐Catalyzed Regiodivergent Asymmetric Difunctionalization of Terminal Alkynes

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: unknown

Published: June 25, 2024

We herein describe the first example of ligand-controlled, copper-catalyzed regiodivergent asymmetric difunctionalization terminal alkynes through a cascade hydroboration and hydroallylation process. The catalytic system, consisting (R)-DTBM-Segphos CuBr, could efficiently achieve 1,1-difunctionalization aryl alkynes, while ligand switching to (S,S)-Ph-BPE result in 1,2-difunctionalization exclusively. In addition, alkyl substituted especially industrially relevant acetylene propyne, were also valid feedstocks for 1,1-difunctionalization. This protocol is characterized by good functional group tolerance, broad scope substrates (>150 examples), mild reaction conditions. showcase value this method late-stage functionalization complicated bioactive molecules simplifying synthetic routes toward key intermediacy natural product (bruguierol A). Mechanistic studies combined with DFT calculations provide insight into mechanism origins ligand-controlled regio- stereoselectivity.

Language: Английский

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