Axially chiral styrene-based organocatalysts and their application in asymmetric cascade Michael/cyclization reaction

Chemical Science, Год журнала: 2023, Номер 14(35), С. 9496 - 9502

Опубликована: Янв. 1, 2023

An axially chiral styrene-based organocatalyst, featuring a combination of structure and pyrrole ring, has been designed synthesized. This catalyst demonstrates remarkable capabilities in producing wide range densely substituted spirooxindoles that feature an alkyne-substituted quaternary stereogenic center. These are generated through mild cascade Michael/cyclization reactions, resulting high conversion rates exceptional enantioselectivity. Our catalytic model, based on experiments, X-ray analysis DFT calculations suggests matched π-π interactions multiple H-bonds between the organocatalyst substrates play significant roles controlling stereoselectivity reaction.

Язык: Английский

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Gold-Catalyzed Double Spirocyclization of 3-Ene-1,7-diyne Esters to Dispiroheterocycles

Organic Letters, Год журнала: 2024, Номер 26(15), С. 3252 - 3257

Опубликована: Апрель 8, 2024

A synthetic method to prepare dispiroheterocycles containing two all-carbon quaternary centers efficiently that relies on the gold(I)-catalyzed double spirocyclization of 3-ene-1,7-diyne esters is described. The suggested mechanism delineates a rare example dispirocyclization featuring 1,n-acyloxy shifts comprising 1,3-acyloxy migration and an interrupted 1,5-acyl was achieved with assistance residual water in reaction media.

Язык: Английский

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Ruthenium-Catalyzed Carbocycle-Selective Hydrogenation of Fused Heteroarenes

Journal of the American Chemical Society, Год журнала: 2024, Номер unknown

Опубликована: Дек. 11, 2024

The homogeneous catalytic hydrogenation of benzo-fused heteroarenes generally provides partially hydrogenated products wherein the heteroaryl ring is preferentially reduced, such as quinoline hydrogenation, leading to 1,2,3,4-tetrahydroquinoline. Herein, we report a carbocycle-selective fused

Язык: Английский

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Concise synthesis and applications of enantiopure spirobiphenoxasilin-diol and its related chiral ligands

Chemical Communications, Год журнала: 2021, Номер 57(98), С. 13365 - 13368

Опубликована: Янв. 1, 2021

The development of chiral architectures for ligand and catalyst discovery is essential asymmetric catalysis. Herein, we report the concise synthesis a Si-centered spirocyclic skeleton, spirobiphenoxasilin-diol (SPOSiOL), its derived ligands. Using chemical resolution method, optical SPOSiOL could be obtained in high yield on gram scale. Preliminary studies indicated that this scaffold has great potential transition metal-catalyzed reactions. This finding further highlights scaffolds are value

Язык: Английский

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A Selective and General Cobalt‐Catalyzed Hydroaminomethylation of Olefins to Amines

Angewandte Chemie International Edition, Год журнала: 2021, Номер 61(2)

Опубликована: Ноя. 5, 2021

Abstract A new cobalt catalyst is presented for the domino hydroformylation‐reductive amination reaction of olefins. The optimal Co‐tert‐BuPy‐Xantphos shows good to excellent linear‐to‐branched (n/iso) regioselectivity reactions aliphatic alkenes with aromatic amines under mild conditions. This system far more selective than traditional cobalt(I) catalysts and even better most known rhodium catalysts.

Язык: Английский

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Nickel Catalyzed Enantioselective 1,4-Hydroamination of 1,3-Dienes

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(27), С. 18440 - 18450

Опубликована: Июль 1, 2024

Transition metal-catalyzed enantioselective hydroamination of 1,3-dienes provides a direct methodology for the construction chiral allylamines. So far, all reported examples used nucleophilic amines and proceeded with 3,4-regioselectivity. Herein, we describe first example nickel-catalyzed 1,4-hydroamination using trimethoxysilane hydroxylamines structurally adaptable aromatic spiroketal based diphosphine (SKP) as ligand, affording wide array α-substituted allylamines in high yields excellent regio- enantioselectivities. This operationally simple protocol demonstrated broad substrate scope functional group compatibility, significantly expanding chemical space Experimental DFT studies were performed to elucidate mechanism rationalize enantioselectivities reaction.

Язык: Английский

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Combining palladium and ammonium halide catalysts for Morita–Baylis–Hillman carbonates of methyl vinyl ketone: from 1,4-carbodipoles to ion pairs

Chemical Science, Год журнала: 2021, Номер 12(34), С. 11399 - 11405

Опубликована: Янв. 1, 2021

Here we report that Morita-Baylis-Hillman carbonates from diverse aldehydes and methyl vinyl ketones can be directly utilised as palladium-trimethylenemethane 1,4-carbodipole-type precursors, both reactivity enantioselectivity are finely regulated by adding a chiral ammonium halide the ion-pair catalyst. The newly assembled intermediates, proposed to contain an electronically neutral π-allylpalladium complex reactive compact ion pair, efficiently undergo asymmetric [4 + 2] annulations with activated alkenes or isatins, generally high regio-, diastereo- enantio-selectivity, even switchable regiodivergent diastereodivergent well realised tuning substrate catalyst assemblies. An array of control experiments, including UV/Vis absorption study density functional theory calculations, conducted rationalise this new double activation mode combining palladium

Язык: Английский

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Asymmetric hydrogenation of γ‐branched allylamines for the efficient synthesis of γ‐chirogenic amines

Natural Sciences, Год журнала: 2021, Номер 1(2)

Опубликована: Авг. 5, 2021

Abstract The efficient construction of γ ‐chirogenic amines has been realized via asymmetric hydrogenation ‐branched N ‐phthaloyl allylamines by using a bisphosphine‐Rh catalyst bearing large bite angle. desired products possessing different ‐substituents were obtained in quantitative yields and with excellent enantioselectivities (up to >99% ee). This protocol provides practical method for the preparation amine derivatives such as famous antidepressant drug Fluoxetine 50000 S/C). mechanistic calculations show an unusual P‐Rh‐P trans ‐chelating pattern weak interaction‐promoted activation mode which are completely from traditional cis coordination‐promoted metal‐catalyzed hydrogenations. Key points Novel methodology was developed synthesis γ‐chirogenic amines. New synthetic route well‐known Fluoxetine. Unusual mechanism information found bidentate bisphosphine‐Rh‐catalyzed hydrogenation.

Язык: Английский

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The Implications of the Brønsted Acidic Properties of Crabtree-Type Catalysts in the Asymmetric Hydrogenation of Olefins

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(36), С. 16252 - 16261

Опубликована: Авг. 31, 2022

Chiral iridium complexes derived from Crabtree's catalyst are highly useful in modern hydrogenations of olefins attributed to high reactivity, stereoselectivity, and stability. Despite that these precatalysts pH neutral, the reaction mixtures turn acidic under hydrogenation conditions. This Perspective is devoted implications intrinsic Brønsted acidity catalytic intermediates asymmetric olefins. has often been used only as a rationale for side-product formation, more recent methodologies have started use this property advantageously. We hope serves stimulant development such compelling new hydrogenations. The inherent scientific opportunities utilizing or annihilating generated acid enormous, potential innovations outlined toward end.

Язык: Английский

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Palladium-Catalyzed Modular Assembly of P-Stereogenic and Axially Chiral Phosphinooxazoles (PHOX) Ligands by C–P Bond Cleavage/Intermolecular C(sp²)–H Bond Functionalization

Organic Letters, Год журнала: 2023, Номер 25(42), С. 7705 - 7710

Опубликована: Окт. 13, 2023

Chiral P,N-ligands are of great interest and importance in the fields metal-catalyzed enantioselective transformations have found numerous applications spanning drug polymer synthesis. Here, modular assembly diverse P-stereogenic axially chiral phosphinooxazoles ligands is achieved through palladium-catalyzed asymmetric cleavage C-P bond/intermolecular C-H bond functionalization high atroposelectivities diastereoselectivities up to >99% ee >25:1 dr. This protocol features broad substrate scope provides an avenue for facile construction new directly from phosphonium salts benzoxazoles/benzothiazoles. Evaluation synthesized two model catalytic reactions illustrates potential our strategy access valuable molecules.

Язык: Английский

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