Asymmetric dearomatization catalysed by chiral Brønsted acids via activation of ynamides

Nature Chemistry, Год журнала: 2021, Номер 13(11), С. 1093 - 1100

Опубликована: Окт. 11, 2021

Язык: Английский

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Organocatalytic Enantioselective Synthesis of Chiral Allenes: Remote Asymmetric 1,8‐Addition of Indole Imine Methides

Angewandte Chemie International Edition, Год журнала: 2020, Номер 59(39), С. 17049 - 17054

Опубликована: Июнь 18, 2020

An organocatalytic enantioconvergent synthesis of chiral tetrasubstituted allenes is disclosed. With suitable phosphoric acid catalysts, a range racemic indole-substituted propargylic alcohols reacted with nucleophiles to provide efficient access series enantioenriched high enantioselectivities. Control experiments suggested mechanism involving remotely controlled asymmetric 1,8-addition the in situ generated indole imine methide via bifunctional transition state.

Язык: Английский

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Asymmetric Intramolecular Dearomatization of Nonactivated Arenes with Ynamides for Rapid Assembly of Fused Ring System under Silver Catalysis

Journal of the American Chemical Society, Год журнала: 2020, Номер 143(2), С. 604 - 611

Опубликована: Дек. 31, 2020

Arene dearomatization is a straightforward method for converting an aromatic feedstock into functionalized carbocycles. Enantioselective dearomatizations of chemically inert arenes, however, are quite limited and underexplored relative to those phenols indoles. We developed diazo-free generation silver-carbene species from ynamide applied it the nonactivated arenes. Transiently generated norcaradiene could be trapped by intermolecular [4 + 2] cycloaddition, synthesizing polycycles with five consecutive stereogenic centers. This protocol constitutes first highly enantioselective reaction based on species. Mechanistic investigations revealed followed two different classes pericyclic reactions, as well origin chemo- enantioselectivity.

Язык: Английский

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Brønsted Acid Catalyzed Dearomatization by Intramolecular Hydroalkoxylation/Claisen Rearrangement: Diastereo‐ and Enantioselective Synthesis of Spirolactams

Angewandte Chemie International Edition, Год журнала: 2021, Номер 60(52), С. 27164 - 27170

Опубликована: Окт. 21, 2021

Described herein is a novel Brønsted acid catalyzed intramolecular hydroalkoxylation/Claisen rearrangement, allowing the practical and atom-economic synthesis of range valuable spirolactams from readily available ynamides in generally good to excellent yields with diastereoselectivities broad substrate scope. Importantly, an unexpected dearomatization nonactivated arenes heteroaromatic compounds involved this tandem sequence. Moreover, asymmetric version cyclization was also achieved by efficient kinetic resolution chiral phosphoric catalysis. In addition, [3,3]-rearrangement shown be kinetically preferred over related [1,3]-rearrangement theoretical calculations.

Язык: Английский

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Design and synthesis of axially chiral aryl-pyrroloindoles via the strategy of organocatalytic asymmetric (2 + 3) cyclization

Fundamental Research, Год журнала: 2022, Номер 3(2), С. 237 - 248

Опубликована: Янв. 21, 2022

The catalytic asymmetric construction of axially chiral indole-based frameworks is an important area research due to the unique characteristics such frameworks. Nevertheless, in this still its infancy and has some challenges, as designing constructing new classes scaffolds developing their applications catalysts, ligands, etc. To overcome these we present herein design atroposelective synthesis aryl-pyrroloindoles a class via strategy organocatalytic (2 + 3) cyclization between 3-arylindoles propargylic alcohols. More importantly, was derived into phosphines, which served efficient ligands palladium-catalyzed reactions. Moreover, theoretical calculations provided in-depth understanding reaction mechanism. This work offers for scaffolds, are promising finding more catalysis.

Язык: Английский

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Asymmetric Dearomatization of Nonfunctionalized 1-Naphthols via Copper-Catalyzed Enantioselective [4 + 1] Spiroannulation

ACS Catalysis, Год журнала: 2024, Номер 14(12), С. 9244 - 9253

Опубликована: Июнь 3, 2024

Catalytic asymmetric dearomatization (CADA) is a powerful tool for the rapid construction of complex chiral three-dimensional cyclic molecules featuring quaternary carbon centers from readily available arenes. However, ubiquitous nonfunctionalized 1-naphthols to afford remains challenging and undeveloped. This study reports dearomative [4 + 1] spiroannulation via copper catalysis. reaction features highly chemo-, regio-, stereoselective nucleophilic addition intramolecular annulation cascade reactive π-extended copper-allenylidene, thus enabling practical synthesis range valuable spirocyclic enones bearing stereocenter with high efficiency. Furthermore, this protocol applicable phenols. Control experiments supported substitution-annulation mechanism by excluding process involving 1,3-sigmatropic shift. Preliminary biological activity studies indicated that synthesized hold significant promise as anticancer agents inducing tumor cell apoptosis.

Язык: Английский

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Chiral phosphoric acid-catalyzed regio- and enantioselective reactions of functionalized propargylic alcohols

Organic Chemistry Frontiers, Год журнала: 2022, Номер 9(5), С. 1234 - 1240

Опубликована: Янв. 1, 2022

Chiral phosphoric acid has been utilized for covalent activation of propargylic alcohols to act as pre-catalyst. With this mode, a range highly regio- and enantioenriched heterocyclic products could be generated efficiently from racemic alcohols.

Язык: Английский

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Design and Organocatalytic Asymmetric Synthesis of Indolyl-Pyrroloindoles Bearing Both Axial and Central Chirality

The Journal of Organic Chemistry, Год журнала: 2022, Номер 88(12), С. 7684 - 7702

Опубликована: Ноя. 23, 2022

An axially chiral indolyl-pyrroloindole scaffold, a new member of indole-based scaffolds, has been designed, and the catalytic asymmetric construction this scaffold established by strategy organocatalytic (2 + 3) cycloaddition 3,3'-bisindoles with isoindolinone-based propargylic alcohols. By approach, series derivatives bearing both axial chirality central were synthesized in high yields excellent diastereo- enantioselectivities (up to 95% yield, 91:9 dr, 99% ee). This reaction not only realizes first n) as 1,2-dinucleophiles but also provides for atroposelective scaffolds five-five-membered rings, thus solving challenges constructing class scaffolds.

Язык: Английский

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Organocatalytic Enantioselective 1,10-Addition of Alkynyl Indole Imine Methides with Thiazolones: An Access to Axially Chiral Tetrasubstituted Allenes

Organic Letters, Год журнала: 2022, Номер 24(27), С. 4914 - 4918

Опубликована: Июнь 30, 2022

An asymmetric organocatalytic remote 1,10-addition of alkynyl indole imine methides generated in situ from α-(6-indolyl) propargylic alcohols with thiazolones has been developed for the first time, affording axially chiral tetrasubstituted allenes featuring vicinal sulfur-containing quaternary carbon stereocenters high yields excellent stereoselectivities. The representative scale-up reaction and transformations 1,10-adduct were examined. mechanism was expounded by control experiments DFT calculations.

Язык: Английский

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Catalyst-Controlled Divergent Reactions of 2,3-Disubstituted Indoles with Propargylic Alcohols: Synthesis of 3H-Benzo[b]azepines and Axially Chiral Tetrasubstituted Allenes

Organic Letters, Год журнала: 2022, Номер 24(35), С. 6472 - 6476

Опубликована: Авг. 30, 2022

Catalyst-controlled divergent reactions of 2,3-disubstituted indoles with propargylic alcohols were developed for the first time. In presence TsOH or B(C6F5)3 as catalyst, reacted smoothly 3-alkynyl-3-hydroxyisoindolinones to afford 3H-benzo[b]azepines by selective C2(sp2)-C3(sp2) ring expansion indoles. contrast, decreasing catalyst strength (e.g., chiral phosphoric acid) interrupted cascade reactions, affording axially tetrasubstituted allenes bearing an adjacent quaternary carbon stereocenter. Control experiments provided insights into reaction mechanism.

Язык: Английский

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