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

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(39), С. 26766 - 26776

Опубликована: Сен. 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

Язык: Английский

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Alkene Isomerization Using a Heterogeneous Nickel-Hydride Catalyst

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(22), С. 15596 - 15608

Опубликована: Май 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.

Язык: Английский

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Highly Regioselective Cobalt‐Catalyzed Hydroboration of Internal Alkynes

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(36)

Опубликована: Июль 13, 2022

Herein, we report the development of new Co complexes that have cyclopropane-based diphosphine ligands and can catalyze highly chemo-, regio-, stereoselective hydroboration reactions unsymmetrical internal alkynes. These exhibited unusual regioselectivity: specifically, aryl alkyl alkynes showed excellent cis-β-addition selectivity, dialkyl gave cis-α-addition selectivity. Highly regioselective cannot be achieved by other known methods. The described herein are synthetically useful, particularly for synthesis trisubstituted alkenylborates alkenes. Mechanistic studies indicate a CoI -H species is plausible active catalyst rigid structure cyclopropane skeleton crowded reaction pocket were responsible unprecedented regioselectivity.

Язык: Английский

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Trisubstituted alkenes featuring aryl groups: stereoselective synthetic strategies and applications

Science China Chemistry, Год журнала: 2023, Номер 66(5), С. 1261 - 1287

Опубликована: Апрель 17, 2023

Язык: Английский

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Switching between Hydrogenation and Olefin Transposition Catalysis via Silencing NH Cooperativity in Mn(I) Pincer Complexes

ACS Catalysis, Год журнала: 2022, Номер 12(17), С. 10818 - 10825

Опубликована: Авг. 19, 2022

While Mn-catalyzed (de)hydrogenation of carbonyl derivatives has been well established, the reactivity Mn hydrides with olefins remains very rare. Herein, we report a Mn(I) pincer complex that effectively promotes site-controlled transposition olefins. This is shown to emerge once N-H functionality within Mn/NH bifunctional suppressed by alkylation. detrimental for (de)hydrogenation, such masking cooperative allows highly efficient conversion wide range allylarenes higher-value 1-propenybenzenes in near-quantitative yield excellent stereoselectivities. The toward single positional isomerization was also retained long-chain alkenes, resulting regioselective formation 2-alkenes, which are less thermodynamically stable compared other possible products. detailed mechanistic analysis reaction between activated catalyst and points catalysis operating via metal-alkyl mechanism-one three conventional mechanisms previously unknown complexes.

Язык: Английский

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Synthesis of Tri‐ and Tetrasubstituted Alkenyl Boronates from Alkynes

European Journal of Organic Chemistry, Год журнала: 2022, Номер 2022(30)

Опубликована: Июль 8, 2022

Abstract The synthesis of organoboron compounds have attracted the attention synthetic community. In particular, molecules with C(sp 2 )‐B bonds enable transformation to new C−C or C‐heteroatom by well‐established methodologies. Alkenyl boronates possibility for further conversion boron moiety functionalization double bond. This review gives an overview on recent methodologies selective preparation challenging highly substituted alkenyl from alkynes.

Язык: Английский

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Iron‐Catalyzed Positional and Geometrical Isomerization of Alkenes

Advanced Synthesis & Catalysis, Год журнала: 2023, Номер 365(8), С. 1100 - 1111

Опубликована: Фев. 20, 2023

Abstract This review outlines the most noteworthy achievements of last few years in renascent field positional and geometrical isomerization alkenes using iron catalysis, from a mechanistic perspective. Particular attention will be placed on developments beyond seminal contributions carbonyl complexes their aspects underlying nature active species. The relevant literature has been covered until late 2022. magnified image

Язык: Английский

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Ligand-enabled stereodivergence in nickel-catalyzed regioselective hydroboration of internal allenes

Chem, Год журнала: 2022, Номер 9(1), С. 198 - 215

Опубликована: Ноя. 2, 2022

Язык: Английский

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DMDA-PatA mediates RNA sequence-selective translation repression by anchoring eIF4A and DDX3 to GNG motifs

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Сен. 2, 2024

Small-molecule compounds that elicit mRNA-selective translation repression have attracted interest due to their potential for expansion of druggable space. However, only a limited number examples been reported date. Here, we show desmethyl desamino pateamine A (DMDA-PatA) represses in an manner by clamping eIF4A, DEAD-box RNA-binding protein, onto GNG motifs. By systematically comparing multiple eIF4A inhibitors ribosome profiling, found DMDA-PatA has unique mRNA selectivity repression. Unbiased Bind-n-Seq reveals DMDA-PatA-targeted exhibits preference motifs ATP-independent manner. This unusual RNA binding sterically hinders scanning 40S ribosomes. combination classical molecular dynamics simulations and quantum chemical calculations, the subsequent development inactive derivative positive charge tertiary amine on trienyl arm induces G selectivity. Moreover, identified DDX3, another is alternative target with same effects eIF4A. Our results provide example sequence-selective anchoring proteins inhibition protein synthesis small-molecule compounds. Here authors report DMDA-PatA, anti-tumor compound, functions as translational inhibitor. drug clamps DDX3 motif, providing steric hindrance

Язык: Английский

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Iron-Catalyzed Regioselective C═C Bond Migration and Reductive Deuteration

The Journal of Organic Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Апрель 28, 2025

We report a well-defined multifunctional iron catalyst, Cp*Fe(Ph2PN = C5H4N), that promotes the rearrangement of β,γ-unsaturated ketones, esters, and amides to their α,β-isomers, enabling regioselective C═C reductive deuteration. This iron-catalyzed protocol showcases synthesis diverse range α,β-dideuterated organic compounds, demonstrating broad substrate compatibility under mild conditions. Mechanism studies provide insights into bond relocation cooperative D2 activation.

Язык: Английский

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