Synthesis of Azepinoindoles and Oxepinoindoles through Brønsted-Acid-Catalyzed Cyclization of an In Situ Generated Dihydrospiroquinoline Intermediate

Organic Letters, Journal Year: 2024, Volume and Issue: 26(18), P. 3911 - 3916

Published: May 1, 2024

We have developed a straightforward and efficient synthetic protocol to produce 5,6,7,12-tetrahydrobenzo[2,3]azepino[4,5-

Language: Английский

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Polycyclic Pyrazoles from Alkynyl Cyclohexadienones and Nonstabilized Diazoalkanes via [3 + 2]-Cycloaddition/[1,5]-Sigmatropic Rearrangement/Aza-Michael Reaction Cascade

Organic Letters, Journal Year: 2024, Volume and Issue: 26(4), P. 839 - 844

Published: Jan. 22, 2024

An efficient method for the stereoselective synthesis of "all center substituted" polycyclic pyrazoles from alkynyl cyclohexa-2,5-dienones and nonstabilized diazoalkanes via sequential [3 + 2]-cycloaddition/[1,5]-sigmatropic rearrangement aza-Michael reactions is reported. The developed process highly regioselective stereoselective. It employs a wide substrate scope to furnish structurally diverse linear bridged [4.4.n.0] ring-fused in moderate good yields. One-pot gram-scale syntheses synthetic transformations have also been showcased.

Language: Английский

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Building an All Carbon Quaternary Center via Redox-Neutral Geminal Dual C–H Functionalization of Oxindoles

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

Published: Feb. 18, 2025

Reported here is a catalytic redox-neutral geminal dual C-H functionalization of oxindoles with two distinct aromatics using anilines. The reaction proceeded through pluripotent tetra-substituted alkene intermediate via an extended resonance stabilized carbocation. It furnished wide chemical space around the generation all carbon quaternary centers (>35 examples) in good to excellent yields. developed process highly regioselective and scalable, conditions are environmentally benign nature.

Language: Английский

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Palladium(II)-Catalyzed Desymmetrization of 2-Alkynylbenzoate-Tethered Cyclohexadienones for the Synthesis of Polycyclic Compounds

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

Published: May 17, 2025

Pd-catalyzed cascade cyclization of 2-alkynylbenzoate-tethered cyclohexadienone was developed for the single step synthesis isocoumarin-fused dihydrochromenones. This highly atom economical method proceeds via 6-endo-dig tert-butyl benzoate with a tethered alkyne. By modulating reaction solvent and metal catalyst, methodology diverted purposeful either E/Z tetra-substituted alkenes.

Language: Английский

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Synthesis of Tetrasubstituted Olefins Through Nucleophilic Addition–Oxidation Cascade Reaction via Base Catalysis

ChemistrySelect, Journal Year: 2025, Volume and Issue: 10(20)

Published: May 1, 2025

Abstract An efficient addition‐oxidation cascade reaction has been developed between α‐ aminomaleimide and vinylogous oxindole with strong electron‐withdrawing group (‐CN or ‐COCOOR), enabling the synthesis of a diverse array tetrasubstituted olefins high yields exceptional diastereoselectivities (up to 98% yield up >20:1 Z / E ). The tolerance free amine investigated, results demonstrated that most could not affect nucleophilic addition step except for aliphatic primary amines. Mechanistic investigations confirmed formation an intermediate (detected by HRMS), providing key insights into pathway. Futher study on thermodynamic calculations indicated stereoselectivity oxidation was promoted generating more thermodynamically stable ‐tetrasubstituted olefins. reactions also proceeded smoothly large scale, further proving their synthetic value. This strategy, in authors’ previous work, facilitates substrate‐directed switchable chemodivergent transformations, enhancing flexibility broadening potential applications.

Language: Английский

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Anion-Relay Double Aza-Michael–Michael Cascades to Enone-Tethered Cyclohexadienones: Access to an Intricate Bridged Ring System

Organic Letters, Journal Year: 2024, Volume and Issue: 26(27), P. 5602 - 5608

Published: June 26, 2024

An anion-relay double aza-Michael–Michael addition strategy has been reported for the synthesis of intricate scaffolds from enone-tethered cyclohexadienones and primary amines. This method discloses base-catalyzed highly valued bridged aza-tricyclic frameworks with a high level product selectivity stereoselectivity. Gram scale synthetic transformation were shown to afford structurally diverse aza-polycyclic Control experiments kinetic profile studied determine plausible reaction mechanism.

Language: Английский

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Six-membered ring systems: With O and/or S atoms

Progress in heterocyclic chemistry, Journal Year: 2024, Volume and Issue: unknown, P. 421 - 484

Published: Jan. 1, 2024

Language: Английский

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