Organocatalyzed Intermolecular Asymmetric Allylic Dearomatization of Both α- and β-Naphthols

Organic Letters, Год журнала: 2018, Номер 21(1), С. 330 - 334

Опубликована: Дек. 26, 2018

The first highly stereoselective intermolecular catalytic asymmetric dearomatization (CADA) of α-naphthols through C-C formation and the allylic naphthols by chiral organocatalysis have been achieved. These new complete atom-economic reactions provide enantioriched α- β-naphthalenones bearing an all-carbon quaternary center.

Язык: Английский

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Construction of Vicinal All-Carbon Quaternary Stereocenters Enabled by a Catalytic Asymmetric Dearomatization Reaction of β-Naphthols with 3-Bromooxindoles

ACS Catalysis, Год журнала: 2018, Номер 8(11), С. 10888 - 10894

Опубликована: Окт. 22, 2018

The organocatalyzed asymmetric dearomative addition of phenols to indol-2-ones generated in situ from 3-bromooxindoles was reported. This methodology leads the efficient construction a series enantioenriched 3,3′-disubstituted oxindoles bearing vicinal all-carbon quaternary stereocenters via dearomatization process under mild reaction conditions. Additionally, representative large-scale reactions and related transformations dearomatized products reveal potential synthetic utility this protocol.

Язык: Английский

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Organocatalytic Asymmetric Dearomatization of 3-Nitroindoles and 3-Nitrobenzothiophenes via Thiol-Triggered Diastereo- and Enantioselective Double Michael Addition Reaction

Organic Letters, Год журнала: 2019, Номер 21(14), С. 5452 - 5456

Опубликована: Июнь 28, 2019

Organocatalytic asymmetric dearomatization of 3-nitroindoles and 3-nitrobenzothiophenes by reaction with ethyl 4-mercapto-2-butenoate has been developed. A range chiral tetrahydrothiopheneindolines tetrahydrothiophenebenzothiophenes bearing three contiguous stereocenters are obtained in high yields good diastereoselectivities excellent enantioselectivities. This is the first example thiol-triggered catalytic 3-nitrobenzothiophenes.

Язык: Английский

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Stereodivergent Synthesis of Tetrahydrofuroindoles through Pd‐Catalyzed Asymmetric Dearomative Formal [3+2] Cycloaddition

Angewandte Chemie, Год журнала: 2018, Номер 130(8), С. 2156 - 2160

Опубликована: Янв. 13, 2018

Abstract A stereodivergent synthesis of tetrahydrofuroindoles through palladium‐catalyzed asymmetric dearomative formal [3+2] cycloaddition nitroindoles with epoxybutenes was developed. The polarity the solvent found to play a key role in diastereoselectivity. In toluene, good excellent yields (70–99 %), diastereoselectivity (87/13‐>95/5 d.r.), and enantioselectivity (85/15–94/6 e.r.) were obtained, regardless properties substituents on nitroindoles. acetonitrile, different diastereoisomer produced (75–98 %) stereoselectivity (78/22–93/7 d.r., 93/7–99/1 e.r.). Mechanistic studies conducted illustrate origin diastereodivergency. kinetic experiments indicate that rate‐determining step this reaction is solvents. ESI‐MS also support existence palladium complex intermediates catalytic cycle reaction.

Язык: Английский

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Phosphine‐Catalyzed Enantioselective Dearomative [3+2]‐Cycloaddition of 3‐Nitroindoles and 2‐Nitrobenzofurans

Angewandte Chemie, Год журнала: 2019, Номер 131(16), С. 5476 - 5480

Опубликована: Фев. 12, 2019

Abstract Over the past years, metal‐catalyzed dearomative cycloaddition of 3‐nitroindoles and 2‐nitrobenzofurans have emerged as a powerful protocol to construct chiral fused heterocyclic rings. However, organocatalytic reaction these two classes heteroarenes has become long‐standing challenging task. Herein, we report first example phosphine‐catalyzed asymmetric [3+2]‐cycloadditio 2‐nitrobenzofurans, which provide new, facile, efficient for synthesis 2,3‐fused cyclopentannulated indolines dihydrobenzofurans by reacting with allenoates MBH carbonates, respectively through [3+2]‐cycloaddition.

Язык: Английский

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Enantioselective Organocatalytic Sulfenylation of β-Naphthols

The Journal of Organic Chemistry, Год журнала: 2018, Номер 83(8), С. 4730 - 4738

Опубликована: Март 29, 2018

An enantioselective sulfenylation of β-naphthols has been developed for the first time using a newly synthesized cinchona-derived thiourea as catalyst and N-(arylthio) succinimide (or phthalimide) an electrophilic sulfur source. Various enantioenriched naphthalenones with S-containing all-substituted stereocenter were prepared via dearomatization strategy under mild reaction conditions.

Язык: Английский

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Asymmetric Fluorinative Dearomatization of Tryptophol Derivatives by Chiral Anion Phase‐Transfer Catalysis

Chinese Journal of Chemistry, Год журнала: 2018, Номер 36(10), С. 925 - 928

Опубликована: Июль 28, 2018

Abstract An asymmetric fluorinative dearomatization reaction of tryptophol derivatives was developed via chiral anion phase‐transfer catalysis. Various fluorinated furoindolines were obtained in moderate to excellent yields and enantioselectivity the presence Selectfluor. The preliminary mechanistic studies suggested existence an situ formed boronic ester plays a critical role determining enantioselectivity. This method features facile introduction fluorine atom highly enantioselective manner construction two contiguous quaternary stereogenic centers.

Язык: Английский

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Enantioselective Copper-Catalyzed Electrophilic Dearomative Azidation of β-Naphthols

Organic Letters, Год журнала: 2019, Номер 21(18), С. 7315 - 7319

Опубликована: Сен. 2, 2019

The first example of copper-catalyzed enantioselective dearomative azidation β-naphthols using a readily available N3-transfer reagent is reported. A series 2-hydroxy-1-naphthamides bearing complex N-substituent were converted to the corresponding products in high yields with up 96% ee, and chiral 1-azido-2-hydroxy-1-naphthoates obtained 90% ee under mild reaction conditions. azides could be further transformed into 1,2,3-triazoles smoothly via "click" reaction.

Язык: Английский

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Asymmetric Domino Heck/Dearomatization Reaction of β-Naphthols to Construct Indole–Terpenoid Frameworks

Organic Letters, Год журнала: 2021, Номер 23(20), С. 7865 - 7872

Опубликована: Сен. 28, 2021

A palladium-catalyzed enantioselective Heck cyclization/dearomatization cascade via capturing the cyclized π-allylpalladium intermediate by β-naphthols is reported, which provides a new strategy for construction of chiral indole-terpenoid frameworks. This method affords indole-functionalized β-naphthalenone compounds bearing an all-carbon-substituted quaternary center in excellent yields (up to 92%) and enantioselectivities 94% ee). In addition, utility this showcased gram-scale syntheses diverse transformations dearomatized products.

Язык: Английский

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Pd‐Catalyzed Asymmetric Intramolecular Arylative Dearomatization of para‐Aminophenols^†

Chinese Journal of Chemistry, Год журнала: 2020, Номер 38(7), С. 683 - 689

Опубликована: Март 30, 2020

Summary of main observation and conclusion Asymmetric arylative dearomatization reactions para ‐aminophenols are realized by a Pd‐catalyst consisting TADDOL (α,α,α',α'‐tetraaryl‐2,2‐disubstituted 1,3‐dioxolane‐4,5‐dimethanol)‐derived chiral phosphoramidite ligand. The tetracyclic products bearing the key skeleton Erythrina alkaloids afforded in reasonable yields (up to 73%) with good excellent enantioselectivity 97% ee). Concise total synthesis (–)‐3‐demethoxyerythratidinone is achieved employing this method as step.

Язык: Английский

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