Palladium‐Catalyzed Asymmetric [4+3] Cyclization of Trimethylenemethane: Regio‐, Diastereo‐, and Enantioselective Construction of Benzofuro[3,2‐b]azepine Skeletons

Angewandte Chemie International Edition, Год журнала: 2019, Номер 59(3), С. 1238 - 1242

Опубликована: Ноя. 22, 2019

The palladium-catalyzed asymmetric [4+3] cyclization of trimethylenemethane donors with benzofuran-derived azadienes furnishes chiral benzofuro[3,2-b]azepine frameworks in high yields (up to 98 %) exclusive regioselectivities and excellent stereoselectivities >20:1 d.r., >99 % ee). This catalytic Pd-trimethylenemethane can enrich the arsenal Pd-TMM reactions organic synthesis. In addition, this strategy provides an alternative approach azepines by a transition-metal-catalyzed cyclization.

Язык: Английский

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Construction of All-Carbon Quaternary Stereocenters via Sequential Photoactivation/Isothiourea Catalysis

Organic Letters, Год журнала: 2019, Номер 21(19), С. 7897 - 7901

Опубликована: Сен. 17, 2019

Highly enantioselective [4 + 2] cyclizations of azadienes with in situ generated ketenes were developed through sequential visible-light photoactivation/isothiourea catalysis, which offers a novel approach for the creation all-carbon quaternary stereocenters disubstituted C1-ammonium enolates. The visible-light-induced sustained release reactive ketene species Wolff rearrangement α-diazoketones is crucial achieving high levels chemical efficiency and stereoinduction.

Язык: Английский

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Recent Advances in the Construction of Trifluoromethyl‐Containing Spirooxindoles through Cycloaddition Reactions

Chemistry - An Asian Journal, Год журнала: 2020, Номер 15(8), С. 1225 - 1233

Опубликована: Фев. 27, 2020

The spirooxindole unit is one of the most widely investigated compound skeletons existing in numerous natural and pharmaceutical molecules. Thus, a large number synthetic methodologies have already been reported to construct such core structure. trifluoromethyl group another privileged organic chemistry. introduction CF3 an framework can significantly improve properties molecule. In this context, efficient approach for construction trifluoromethyl-containing spirooxindoles becomes promising research direction among communities industry academia. Minireview, recent advances summarized discussed. addition, representative corresponding reaction mechanisms described as well.

Язык: Английский

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Access to 5,6-Spirocycles Bearing Three Contiguous Stereocenters via Pd-Catalyzed Stereoselective [4 + 2] Cycloaddition of Azadienes

Organic Letters, Год журнала: 2021, Номер 23(8), С. 2884 - 2889

Опубликована: Март 26, 2021

We present herein a highly diastereo- and enantioselective Pd-catalyzed [4 + 2] cycloaddition of benzofuran-derived azadienes with vinyl benzoxazinanones, which represents rare stereoselective this class fused as two-atom synthon. The use phosphoramidite ligand bearing chiral secondary amine simple biphenyl backbone proved to be the key construct novel spirocyclic tetrahydroquinoline scaffold containing three contiguous stereocenters single diastereomer in high enantioselectivity.

Язык: Английский

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Palladium‐Catalyzed Asymmetric [4+3]‐Cyclization Reaction of Fused 1‐Azadienes with Amino‐trimethylenemethanes: Highly Stereoselective Construction of Chiral Fused Azepines

Chinese Journal of Chemistry, Год журнала: 2019, Номер 38(2), С. 151 - 157

Опубликована: Ноя. 20, 2019

Summary of main observation and conclusion A Pd‐catalyzed asymmetric aromative [4+3]‐cyclization reaction amino‐trimethylenemethanes (TMM, 1,3‐dipoles) with fused 1‐azadienes has been developed. This method enables access to the synthetically importance biologically active benzofuran azepines indeno‐azepines in excellent efficiency stereoselectivity (up 95% yield, 99% ee, >19 : 1 dr).

Язык: Английский

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Enantioselective Synthesis of Benzofuran-Fused N-Heterocycles via Chiral Squaramide Catalyzed [4 + 2] Cyclization of Azadienes with Azlactones

The Journal of Organic Chemistry, Год журнала: 2019, Номер 84(12), С. 8035 - 8045

Опубликована: Июнь 3, 2019

An asymmetric cyclization reaction of azadienes and azlactones was investigated by employing a Cinchona squaramide catalyst, which could afford series benzofuran-fused six-membered heterocycles containing α,α-disubstituted amino acid unit in highly diastereoselective (>20:1 dr) enantioselective (up to 99% ee) manner with good excellent yields 92%). A plausible pathway proposed explain the process.

Язык: Английский

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Hydride Transfer Initiated Redox-Neutral Cascade Cyclizations of Aurones: Facile Access to [6,5] Spirocycles

Organic Letters, Год журнала: 2020, Номер 22(7), С. 2537 - 2541

Опубликована: Март 18, 2020

ADVERTISEMENT RETURN TO ISSUEPREVLetterNEXTHydride Transfer Initiated Redox-Neutral Cascade Cyclizations of Aurones: Facile Access to [6,5] SpirocyclesKang DuanKang DuanSchool Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao, 266109, ChinaMore by Kang Duan, Xiao-De AnXiao-De AnSchool An, Long-Fei LiLong-Fei LiSchool Li, Lian-Lian SunLian-Lian SunThe Affiliated Hospital Huizhou Health Sciences Polytechnic, Huizhou, 516025, Sun, Bin QiuBin QiuSchool Qiu, Xian-Jiang LiXian-Jiang LiShandong Kangqiao Biotechnology Co. Ltd., Binzhou, 256500, Jian Xiao*Jian XiaoSchool ChinaSchool Marine Science Engineering, China*E-mail: [email protected]More Xiaohttp://orcid.org/0000-0003-4272-6865Cite this: Org. Lett. 2020, 22, 7, 2537–2541Publication Date (Web):March 18, 2020Publication History Received22 January 2020Published online18 March inissue 3 April 2020https://doi.org/10.1021/acs.orglett.0c00309Copyright © 2020 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views1714Altmetric-Citations25LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum full text article downloads since November 2008 (both PDF HTML) across all institutions individuals. These metrics regularly updated reflect usage leading up last few days.Citations number other articles citing this article, calculated Crossref daily. Find more information about citation counts.The Altmetric Attention Score is a quantitative measure attention that research has received online. Clicking on donut icon will load page at altmetric.com with additional details score social media presence for given article. how calculated. Share Add toView InAdd Full Text ReferenceAdd Description ExportRISCitationCitation abstractCitation referencesMore Options onFacebookTwitterWechatLinked InReddit Read OnlinePDF (1 MB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting SUBJECTS:Addition reactions,Catalysts,Chemical reactions,Stereoselectivity,Substituents e-Alerts

Язык: Английский

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Recent Advances in the Cycloaddition Reactions of 2‐Benzylidene‐1‐benzofuran‐3‐ones, and Their Sulfur, Nitrogen and Methylene Analogues

Chemistry - An Asian Journal, Год журнала: 2020, Номер 15(18), С. 2838 - 2853

Опубликована: Июль 24, 2020

Abstract Benzothiophene, benzofuran, indole, and indene derivatives are privileged heterocyclic motifs. These present in a wide range of bioactive natural products pharmaceutical drugs the subject materials science research. However, construction benzothiophene, frameworks have been long‐standing challenges to organic chemists. In this review, we classify four structures synthesized from 2‐benzylidene‐1‐benzofuran‐3‐one their analogues terms ring size (from three‐ ten‐membered) type (fused or spiro), as well summarizing developments field. Finally, discuss opening 1,4‐addition reactions.

Язык: Английский

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Decarboxylative Bromooxidation of Indoles by a Vanadium Haloperoxidase

ACS Catalysis, Год журнала: 2023, Номер 13(7), С. 4622 - 4628

Опубликована: Март 22, 2023

Halooxindoles are versatile building blocks for the construction of complex oxindole-containing targets biological importance. Despite their synthetic value, catalytic methods to make 3-halooxindoles from readily available starting materials have remained undisclosed. We recently discovered that chloroperoxidase Curvularia inaequalis (CiVCPO) is a viable catalyst decarboxylative bromooxidation 3-carboxyindoles furnish 3-bromooxindoles with excellent regio- and chemoselectivity. In addition development method, this study provides evidence bromide recycling mechanism indole oxidation event. A discussion reaction development, substrate scope, mechanistic insights, applicability will be discussed herein.

Язык: Английский

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DABCO-Catalyzed Michael/Alkylation Cascade Reactions Involving α-Substituted Ammonium Ylides for the Construction of Spirocyclopropyl Oxindoles: Access to the Powerful Chemical Leads against HIV-1

The Journal of Organic Chemistry, Год журнала: 2020, Номер 85(8), С. 5203 - 5219

Опубликована: Март 23, 2020

A novel Michael/alkylation cascade reaction of N-unprotected 3-bromooxindoles with α,β-unsaturated acyl phosphonates using DABCO as a robust catalyst followed by the derivatization phosphonate intermediates in situ has been developed. This scenario enables rapid access to diverse set highly functionalized spirocyclopropyl oxindoles moderate yields good excellent diastereoselectivities, which are analogues high active non-nucleoside reverse transcriptase inhibitor against HIV-1. The synthetic potential this tactic highlighted gram-scale and Suzuki cross-coupling reactions product. Moreover, mechanism tentatively elucidated control experiments dynamic high-resolution mass spectrometry studies, indicates that involves DABCO-derived α-substituted ammonium ylides.

Язык: Английский

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