Recent advances in organocatalytic asymmetric multicomponent cascade reactions for enantioselective synthesis of spirooxindoles

Organic Chemistry Frontiers, Год журнала: 2021, Номер 8(15), С. 4315 - 4348

Опубликована: Янв. 1, 2021

Catalytic asymmetric MCCRs for enantioselective synthesis of spirooxindoles by using chiral phosphoric acids, amines, bifunctional thiourea/squaramides and metal-based reagents as catalysts.

Язык: Английский

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Enantio‐ and Diastereodivergent Synthesis of Spirocycles through Dual‐Metal‐Catalyzed [3+2] Annulation of 2‐Vinyloxiranes with Nucleophilic Dipoles

Angewandte Chemie International Edition, Год журнала: 2021, Номер 60(47), С. 24941 - 24949

Опубликована: Сен. 17, 2021

The development of efficient and straightforward methods for obtaining all optically active isomers structurally rigid spirocycles from readily available starting materials is great value in drug discovery chiral ligand development. However, the stereodivergent synthesis bearing multiple stereocenters remains an unsolved challenge owing to steric hindrance ring strain. Herein, we report enantio- diastereodivergent through dual-metal-catalyzed [3+2] annulation oxy π-allyl metallic dipoles with less commonly employed nucleophilic (imino esters). A series spiro compounds a pyrroline olefin were easily synthesized manner (up 19:1 dr, >99 % ee), which showed promise as new type N-olefin ligand. Preliminary mechanistic studies also carried out understand process this bimetallic catalysis.

Язык: Английский

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Switching between the [2π+2σ] and Hetero‐[4π+2σ] Cycloaddition Reactivity of Bicyclobutanes with Lewis Acid Catalysts Enables the Synthesis of Spirocycles and Bridged Heterocycles

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(29)

Опубликована: Май 11, 2024

Abstract The exploration of the complex chemical diversity bicyclo[n.1.1]alkanes and their use as benzene bioisosteres has garnered significant attention over past two decades. Regiodivergent syntheses thiabicyclo[4.1.1]octanes (S‐BCOs) highly substituted bicyclo[2.1.1]hexanes (BCHs) using a Lewis acid‐catalyzed formal cycloaddition bicyclobutanes (BCBs) 3‐benzylideneindoline‐2‐thione derivatives have been established. first hetero‐(4+3) BCBs, catalyzed by Zn(OTf) 2 , was achieved with broad substrate scope under mild conditions. In contrast, less electrophilic BCB ester undergoes Sc(OTf) 3 ‐catalyzed [2π+2σ] reaction 1,1,2‐trisubstituted alkenes, yielding BCHs spirocyclic quaternary carbon center. Control experiments preliminary theoretical calculations suggest that diastereoselective product formation may involve concerted between zwitterionic intermediate E ‐1,1,2‐trisubstituted alkenes. Additionally, nucleophilic ring‐opening mechanism.

Язык: Английский

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Catalytic enantioselective construction of vicinal quaternary carbon stereocenters

Chemical Science, Год журнала: 2020, Номер 11(35), С. 9341 - 9365

Опубликована: Янв. 1, 2020

This review summarizes the advances in catalytic enantioselective construction of vicinal quaternary carbon stereocenters, introduces major synthetic strategies and discusses their advantages limitations, outlines opportunities.

Язык: Английский

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Highly Selective and Catalytic Generation of Acyclic Quaternary Carbon Stereocenters via Functionalization of 1,3-Dienes with CO₂

Journal of the American Chemical Society, Год журнала: 2019, Номер 141(47), С. 18825 - 18835

Опубликована: Ноя. 8, 2019

The catalytic asymmetric functionalization of readily available 1,3-dienes is highly important, but current examples are mostly limited to the construction tertiary chiral centers. generation acyclic products containing all-carbon quaternary stereocenters from substituted represents a more challenging, desirable, synthetic process for which there very few examples. Herein, we report selective copper-catalyzed via with CO2. A variety 1,1-disubstituted 1,3-dienes, as well 1,3,5-triene, undergo reductive hydroxymethylation high chemo-, regio-, E/Z-, and enantioselectivities. reported method features good functional group tolerance, scaled up at least 5 mmol starting diene, generates that useful building blocks further derivatization. Systemic mechanistic investigations using density theory calculations were performed provided first theoretical investigation an transformation involving These computational results indicate 1,2-hydrocupration 1,3-diene proceeds π-facial selectivity generate (S)-allylcopper intermediate, induces chirality carbon center in final product. 1,4-addition internal allylcopper complex, differs previous reports terminal allylmetallic intermediates, CO2 kinetically determines E/Z- regioselectivity. rapid reduction copper carboxylate intermediate corresponding silyl-ether presence Me(MeO)2SiH provides exergonic impetus leads chemoselective rather than carboxylation. provide new insights guiding development C-C bond formations

Язык: Английский

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Rhodium(III)‐Catalyzed Asymmetric Access to Spirocycles through C−H Activation and Axial‐to‐Central Chirality Transfer

Angewandte Chemie International Edition, Год журнала: 2020, Номер 59(18), С. 7188 - 7192

Опубликована: Фев. 3, 2020

Axial-to-central chirality transfer is an important strategy to construct chiral centers, where the axially reagents are mostly limited atropomerically stable ones. Reported herein a RhIII -catalyzed enantioselective spiroannulative synthesis of nitrones. The coupling proceeds via C-H arylation give metastable biaryl, followed by intramolecular dearomative trapping under oxidative conditions with high degree transfer.

Язык: Английский

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Small rings in the bigger picture: ring expansion of three- and four-membered rings to access larger all-carbon cyclic systems

Chemical Society Reviews, Год журнала: 2021, Номер 50(13), С. 7513 - 7538

Опубликована: Янв. 1, 2021

Ring-expansion of strained small-size rings to forge larger all-carbon ones, allows a rapid build-up molecular complexity.

Язык: Английский

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Asymmetric Dearomatization of Indole by Palladium/PC‐Phos‐Catalyzed Dynamic Kinetic Transformation

Angewandte Chemie International Edition, Год журнала: 2020, Номер 59(49), С. 21991 - 21996

Опубликована: Сен. 2, 2020

Abstract A palladium‐catalyzed intermolecular dynamic kinetic asymmetric dearomatization of 3‐arylindoles with internal alkynes was developed the use achiral Xantphos and chiral sulfinamide phosphine ligand ( PC‐Phos ) as co‐ligands. This method could deliver various spiro[indene‐1,3′‐indole] compounds in good yields (up to 95 % yield) up 98 ee . The salient features transformation include readily available substrates, ease scale‐up versatile functionalization products. mechanistic experiments gave some insights on active intermediates.

Язык: Английский

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Enantioselective Hydrothiolation: Diverging Cyclopropenes through Ligand Control

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(16), С. 6176 - 6184

Опубликована: Апрель 15, 2021

In this article, we advance Rh-catalyzed hydrothiolation through the divergent reactivity of cyclopropenes. Cyclopropenes undergo to provide cyclopropyl sulfides or allylic sulfides. The choice bisphosphine ligand dictates whether pathway involves ring-retention ring-opening. Mechanistic studies reveal origin for switchable selectivity. Our results suggest two pathways share a common cyclopropyl-Rh(III) intermediate. Electron-rich Josiphos ligands promote direct reductive elimination from intermediate afford in high enantio- and diastereoselectivities. Alternatively, atropisomeric (such as DTBM-BINAP) enable ring-opening generate with regiocontrol.

Язык: Английский

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Ligand-Controlled, Palladium-Catalyzed Asymmetric [4+4] and [2+4] Cycloadditions

Organic Letters, Год журнала: 2021, Номер 23(6), С. 2292 - 2297

Опубликована: Март 8, 2021

Ligand-controlled, palladium-catalyzed asymmetric [4+4] and [2+4] cycloaddition reactions of benzofuran-derived azadienes have been developed. Taking advantage chiral P,N-ligand (S,Rp)-PPFA, we obtained a variety benzofuro[2,3-c][1,5] oxazocines in good yields with excellent enantioselectivities via reactions. Employing P,P-ligand (S)-Cl-MeO-BIPHEP, the chemo- regioselectivities were switched to synthesize tetrahydropyran-fused spirocyclic compounds efficiency

Язык: Английский

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