Enantioselective Synthesis of Cyclobutane Derivatives via Cascade Asymmetric Allylic Etherification/[2 + 2] Photocycloaddition

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(40), P. 21752 - 21759

Published: Sept. 28, 2023

Chiral cyclobutane presents as a popular motif in natural products and biologically active molecules, its derivatives have been extensively used key synthons organic synthesis. Herein, we report an efficient synthetic method toward enantioenriched derivatives. The reaction proceeds cascade fashion involving Ir-catalyzed asymmetric allylic etherification visible-light induced [2 + 2] cycloaddition. Readily available branched allyl acetates cinnamyl alcohols are directly the substrates under mild conditions, providing broad range of chiral cyclobutanes good yields with excellent diastereo- enantioselectivities (up to 12:1 dr, >99% ee). It is worth noting that all catalysts were simultaneously added without any separated step this approach. gram-scale diverse transformations product further enhance potential utility method.

Language: Английский

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Asymmetric Photoenolization/Diels–Alder Reaction of 2-Methylbenzaldehydes and 2-Alkylbenzophenones with Chromones

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(9), P. 6687 - 6695

Published: April 16, 2024

The asymmetric photoenolization/Diels–Alder reaction provides a straightforward and atom-economical route to complex chiral polycyclic rings. In comparison with well-developed transformations of 2-alkylbenzophenones, the enantioselective 2-methylbenzaldehydes was challenging due shorter-lived unstable photoenol intermediates. Herein, we present highly chromones. Chiral N,N′-dioxide/ScIII YbIII complexes were found interact both intermediates chromones simultaneously, accelerating Diels–Alder in an efficient stereoselective manner. Experimental studies DFT calculations carried out understand mechanism origin stereoselectivity. addition, 2-alkylbenzophenones suitable substrates. A series fused rings vicinal multisubstituted stereocenters afforded good yields high diastereo- enantioselectivities.

Language: Английский

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Iridium-Catalyzed Diastereo- and Enantioselective [4 + 1] Cycloaddition of Hydroxyallyl Anilines with Sulfoxonium Ylides

Organic Letters, Journal Year: 2023, Volume and Issue: 25(25), P. 4621 - 4626

Published: June 15, 2023

We present here an iridium-catalyzed diastereo- and enantioselective [4 + 1] cycloaddition reaction of hydroxyallyl anilines with sulfoxonium ylides under mild conditions, leading to 3-vinyl indolines in moderate good yields excellent enantioselectivities. Control experiments disclosed a plausible mechanism.

Language: Английский

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Asymmetric Photoinduced Excited-State Nazarov Reaction

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(42), P. 29150 - 29158

Published: Oct. 9, 2024

We report herein the first asymmetric photoinduced excited-state Nazarov reaction of non-aromatic dicyclic divinyl ketones by using hydrogen-bonding catalysis. The enantioselectivity electrocyclization is highly dependent on structural features substrate and its interaction with chiral catalysts. For simple ketone substrates, there no discernible selectivity hydrogen bond coordination between thiourea carbonyl groups substrates in ground state. However, we found that direction was well controlled each model

Language: Английский

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Synthesis of vinyl-substituted alcohols using acetylene as a C2 building block

Chemical Science, Journal Year: 2022, Volume and Issue: 14(7), P. 1912 - 1918

Published: Dec. 23, 2022

Vinyl-substituted alcohols represent a highly useful class of molecular skeletons. The current method typically requires either stoichiometric metallic reagents or preformed precursors. Herein, we report nickel catalysis-enabled synthesis vinyl-substituted via 5-membered oxa-metallacycle. In this protocol, acetylene, the simplest alkyne and abundant feedstock, is employed as an ideal C2 synthon. reaction features mild conditions, good functional group tolerance broad substrate scope. Mechanistic exploration implies that oxa-metallacycle originated from cyclometallation aldehyde acetylene key intermediate for transformation, which then terminated by silane-mediated σ-bond metathesis subsequent reductive elimination.

Language: Английский

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Ir-Catalyzed Asymmetric Cascade Allylation/Spiroketalization Reaction for Stereoselective Synthesis of Oxazoline-Spiroketals

Organic Letters, Journal Year: 2023, Volume and Issue: 25(2), P. 325 - 330

Published: Jan. 6, 2023

An asymmetric cascade allylation/spiroketalization reaction between 2-(1-hydroxyallyl)phenols and 5-methyleneoxazolines is accomplished by using a chiral Ir(I) catalyst derived from commercially available iridium precursor the Carreira ligand. This protocol furnishes class of structurally novel unique oxazoline-spiroketals in up to 86% yield, >99% ee >20:1 dr. Moreover, control experiments reveal that 4,4-disubstitution on necessary avoid aromatization for spiroketalization occur. On basis this, plausible mechanism illustrated.

Language: Английский

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Catalytic asymmetric defluorinative allylation of silyl enol ethers

Chemical Science, Journal Year: 2023, Volume and Issue: 14(26), P. 7147 - 7153

Published: Jan. 1, 2023

The exploitation of an intermolecular Si–F interaction between the substrates, together with chiral Lewis-base catalysis, allows regio-, diastereo- and enantioselective allylation ketone-derived silyl enol ethers allyl fluorides.

Language: Английский

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Total Synthesis of Polycyclic Natural Products via Photoenolization/Diels–Alder Reaction

Accounts of Chemical Research, Journal Year: 2025, Volume and Issue: unknown

Published: April 2, 2025

ConspectusPolycyclic ring systems represent the most common structural features of drug molecules and natural products. Chemical synthesis complex polycyclic with multiple stereogenic centers, especially quaternary carbon stereocenters, has been a significant challenge in field total synthesis. Due to low reactivities substrates congested chemical environments, efficient establishment rings enantioselective construction stereocenters are still ongoing challenges. In our laboratory, we devoted developing new methodologies strategies for syntheses bioactive products exploration their biological potentials. The photoenolization/Diels-Alder (PEDA) reaction recognized as powerful strategy increase synthetic efficiency address aforementioned issues. Over past several years, group systematically reinvestigated this terms its reactivity stereoselectivity developed unique dinuclear metal-promoted process constructing fused or spiro bearing stereocenters. During course investigation, have come realize how rationally design route based on PEDA successfully implement projects.In Account, summarize endeavors journeys development application topologically order draw attention broad utility encourage further uptake. first part, provide details investigation issues reactivity, diastereoselectivity, enantioselectivity. An involving Ti(Oi-Pr)4 TADDOL-type ligands was developed. This enables sterically bulky dienophiles interact transient photoenolized hydroxy-o-quinodimethanes, delivering wide range single vicinal good yields excellent enantioselectivities. second showcase potential tricyclic systems, gem-dimethyl groups located at junction, were efficiently constructed by Ti(Oi-Pr)4-promoted reactions, which enabled three different types products, including aromatic polyketides (anthrabenzoxocinones, fasamycins/naphthacemycins, benastatins), meroterpenoid (oncocalyxone B), halenaquinones (xestoquinone, adociaquinones A B). To access structurally more triterpenoids, namely, perovskones hydrangenones, asymmetric build along contiguous also applied achieve aryltetralin lactone lignans. Furthermore, an intramolecular provides pathway rapid highly hydrophenanthrene stereocenter, facilitating five hasubanan alkaloids. We anticipate that will inspire future innovations progressions photo be expanded applications molecules.

Language: Английский

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Photoinduced Enantioselective Transformations via o-Quinodimethane Intermediates

Tetrahedron Chem, Journal Year: 2025, Volume and Issue: unknown, P. 100131 - 100131

Published: April 1, 2025

Language: Английский

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Catalytic Generation of o-Quinone Dimethides by a Nondiazo Approach via Donor/Donor Platinum Carbenes

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: April 27, 2025

A platinum-catalyzed reaction of enynones with various dienophiles has been developed for the construction tetrahydronaphthalene derivatives, which undergo a Diels-Alder process platinum carbenes and o-quinone dimethide (o-QDM) intermediates. In this protocol, an alkoxy-substituted conjugated enynone is used as nondiazo carbene precursor generation o-QDMs, thereby extending methods available o-QDMs. The characterized by its high atom economy, diastereoselectivity, broad substrate scope.

Language: Английский

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