(Z)-Selective Isomerization of 1,1-Disubstituted Alkenes by Scandium-Catalyzed Allylic C–H Activation

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(39), P. 26766 - 26776

Published: Sept. 20, 2024

The isomerization of 1,1-disubstituted alkenes through 1,3-hydrogen shift is an atom-efficient route for synthesizing trisubstituted alkenes, which are important moieties in many natural products, pharmaceuticals, and organic materials. However, this reaction often encounters regio- stereoselectivity challenges, typically yielding

Language: Английский

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Alkene Isomerization Using a Heterogeneous Nickel-Hydride Catalyst

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(22), P. 15596 - 15608

Published: May 21, 2024

Transition metal-catalyzed alkene isomerization is an enabling technology used to install distal its original site. Due their well-defined structure, homogeneous catalysts can be fine-tuned optimize reactivity, stereoselectivity, and positional selectivity, but they often suffer from instability nonrecyclability. Heterogeneous are generally highly robust continue lack active-site specificity challenging rationally improve through structural modification. Known single-site heterogeneous for utilize precious metals bespoke, expensive, synthetically intense supports. Additionally, have mediocre inspiring us develop a catalyst with active site made readily available compounds of Earth-abundant elements. Previous work demonstrated that very formed upon protonation Ni[P(OEt)3]4 by H2SO4, generating [Ni–H]+ This incredibly active, also decomposes readily, which severely limits utility. Herein we show using solid acid (sulfated zirconia, SZO300), not only this decomposition prevented, high activity maintained, improved selectivity achieved, broader scope functional groups tolerated. Preliminary mechanistic experiments suggest the catalytic reaction likely goes intermolecular, two-electron pathway. A detailed kinetic study comparing state-of-the-art Ni Pd reveals highest seen Ni/SZO300 system. The reactivity Ni/SZO300, limited isomerization; it competent hydroalkenylation, hydroboration, hydrosilylation, demonstrating broad application catalyst.

Language: Английский

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Trendbericht: Organische Chemie 2025

Nachrichten aus der Chemie, Journal Year: 2025, Volume and Issue: 73(3), P. 40 - 70

Published: Feb. 28, 2025

Abstract Highlights von November 2023 bis 2024: die erste Einelektron‐C–C‐σ‐Bindung und Anti‐Bredt‐Verbindung; gesättigte Heterocyclen elektrochemisch funktionalisieren; Ausrichten diskotischer Flüssigkristalle; enantioselektive Wagner‐Meerwein‐Umlagerung reiner Aliphaten; photokatalytisch Furanen zu Pyrrolen; mit Ammoniak primären Arylaminen; Metallschrott recyceln ionischen Flüssigkeiten; terminale Alkene Ni‐Katalysatoren zum (Z)‐ oder (E)‐Alken isomerisieren;neue Fungizide, Medikamente Alkaloide.

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Flash Communication: Oxidative Addition of 3-Iodopyridine at a Nickel Diphosphine Complex: Probing Secondary Borane Effects

Organometallics, Journal Year: 2025, Volume and Issue: unknown

Published: April 9, 2025

Language: Английский

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Proton-Modulated Nickel Hydride Electrocatalysis for the Hydrogenation of Unsaturated Bonds and Olefin Isomerization

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: April 21, 2025

Transition-metal hydrides stand as indispensable intermediates in both energy conversion and organic synthesis. Their electrochemical generation represents a compelling sustainable approach, enabling precise control over the reactivity expanding scope of electrocatalytic hydrogenation isomerization. However, major challenge Ni-catalyzed is competing hydrogen evolution reaction (HER), which has led to various innovative strategies aimed at circumventing Ni-H formation. Here, we pursued an alternative approach by designing bifunctional ligand with pendant amine moiety promote This design enabled selective (semi)hydrogenation diverse range substrates, including terminal internal alkynes, alkenes, aldehydes, achieving unprecedented substrate scope. Remarkably, also demonstrated tunable positional selectivity for olefin isomerization employing different types proton sources. Our method exhibits excellent functional group tolerance, streamlining access pharmaceuticals their derivatives. Computational studies revealed crucial, noninnocent role source modulating metal hydride selectivity, either through bonding, direct protonation amine, or facilitation protodemetalation.

Language: Английский

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Phosphine ligand-dependent nickel-catalyzed regiodivergent isomerization of alkenes

Chem Catalysis, Journal Year: 2024, Volume and Issue: 4(8), P. 101089 - 101089

Published: Aug. 1, 2024

Language: Английский

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Access to Alkenyl Cyclobutanols by Ni‐Catalyzed Regio‐ and Enantio‐selective syn‐Hydrometalative 4‐exo‐trig Cyclization of Alkynones

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

Published: Oct. 12, 2024

Abstract Enantioselective synthesis of (spiro)cyclobutane derivatives poses significant challenges yet holds promising applications for both synthetic and medicinal chemistry. We report here a nickel‐catalyzed asymmetric syn ‐hydrometalative 4‐ exo ‐ trig cyclization 1,4‐alkynones to synthesize alkenyl cyclobutanols with tetrasubstituted stereocenter. This strategy features broad substrate scope, delivering variety trifluoromethyl‐containing rigid (spiro)carbocycle skeletons in good yields high enantioselectivities (up 84 % yield 98.5 : 1.5 er). The utility is demonstrated through stereospecific transformations into fused spiro molecules. Experimental computational mechanistic studies indicate that the reaction initiated by an active Ni−H species, carbonyl‐directed hydrometalation as key regioselective control. catalytic method provides general solution hydrofunctionalization alkynes represents efficient pattern assembling highly strained enantioenriched bioisosteres.

Language: Английский

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Alkene Isomerization using a Heterogeneous Nickel-Hydride Catalyst

Published: May 13, 2024

Transition metal-catalyzed alkene isomerization is an enabling technology used to install distal its original site. Due their well-defined structure, homogeneous catalysts can be fine-tuned optimize reactivity, stereoselectivity, and positional selectivity, but they often suffer from instability non-recyclability. Heterogeneous are generally highly robust continue lack active-site specificity challenging rationally improve through structural modification. Known single-site heterogeneous for utilize precious metals bespoke, expensive, synthetically intense supports. Additionally, have mediocre inspiring us develop a catalyst with active site made readily available compounds of Earth-abundant elements. Previous work demonstrated that very formed upon protonation Ni[P(OEt)3]4 by H2SO4, generating [Ni–H]+ This incredibly active, also decomposes readily, which severely limits utility. Herein we show using solid acid (sulfated zirconia, SZO300), not only this de-composition prevented, high activity maintained, improved selectivity achieved, broader scope functional groups tolerated. Preliminary mechanistic experiments suggest the catalytic reaction likely goes intermolecular, two-electron pathway. A detailed kinetic study comparing state-of-the-art Ni Pd reveals highest seen Ni/SZO300 system. The reactivity Ni/SZO300, limited isomerization; it competent hydroalkenylation, hydroboration, hydrosilylation, demonstrating broad application catalyst.

Language: Английский

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Nickel-hydrogen-bonding-enabled, phosphine-ligand-tuned regiodivergent isomerization of olefins

Chem Catalysis, Journal Year: 2024, Volume and Issue: 4(8), P. 101043 - 101043

Published: July 4, 2024

Language: Английский

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Selective C–H activation of unprotected allylamines by control of catalyst speciation

Chem Catalysis, Journal Year: 2023, Volume and Issue: 3(11), P. 100809 - 100809

Published: Nov. 1, 2023

Language: Английский

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