Divergent Enantioselective Access to Diverse Chiral Compounds from Bicyclo[1.1.0]butanes and α,β-Unsaturated Ketones under Catalyst Control

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 30, 2024

Achieving structural and stereogenic diversity from the same starting materials remains a fundamental challenge in organic synthesis, requiring precise control over selectivity. Here, we report divergent catalytic methods that selectively yield either cycloaddition or addition/elimination products bicyclo[1.1.0]butanes α,β-unsaturated ketones. By employing chiral Lewis acid Brønsted catalysts, achieved excellent regio-, diastereo-, enantioselectivity across all three distinct transformations, affording diverse array of synthetically valuable bicyclo[2.1.1]hexanes cyclobutenes. The outcomes are controlled by differential activation substrates specific catalyst with reaction conditions dictating pathway This strategy demonstrates power catalysis creating molecular complexity diversity, offering tool for synthesis enantioenriched building blocks.

Language: Английский

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Sc-Catalyzed Asymmetric [2 + 2] Annulation of 2-Alkynylnaphthols with Dienes to Access Cyclobutene Frameworks

Organic Letters, Journal Year: 2025, Volume and Issue: 27(4), P. 1006 - 1011

Published: Jan. 16, 2025

Herein, we introduce a scandium-catalyzed synthetic strategy that provides access to diverse and functionalized array of cyclobutene frameworks adorned with quaternary carbon center. This approach broadens the repertoire 2-alkynylnaphthols alkenes, offering versatile platform for construction complex molecular architectures. The asymmetric catalytic [2 + 2] cycloaddition reaction demonstrates wide substrate scope an impressive functional group tolerance, yielding products high efficiency, up 97% yield, excellent enantiomeric excess 97%. simplicity scaling this process, coupled ease converting these into variety substituted products, significantly enhances utility method.

Language: Английский

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Continuous flow synthesis of cyclobutenes via lithium ynolates

Green Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Batch reactions that involve the generation of highly reactive species require a cryogenic temperature, complicated manipulations by chemists, and higher amounts reagents, resulting in energy wastage high costs.

Language: Английский

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Stereoselective Alkyne–Alkene [2 + 2] Cycloaddition Enabled by Anion Relay Chemistry for Fully C-Substituted Cyclobutene Synthesis

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

Published: Feb. 6, 2025

Cyclobutenes serve as valuable scaffolds in pharmaceutical development, but synthesizing structurally diverse fully C-substituted cyclobutenes remains challenging. Here we report a stereoselective [2 + 2] cycloaddition between alkynyl 1,3-dithianes and cinnamate esters using catalytic amount of KOtBu. Our approach enables the construction synthetically challenging tetrasubstituted via anion relay chemistry (ARC), exhibiting excellent trans-diastereoselectivities (dr > 20:1).

Language: Английский

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Catalytic Schmittel-Type [2+2] Cycloaddition of γ-Alkynyl Diazoacetates with Terminal Alkynes for Accessing Cyclobuta[a]indenes

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

Published: March 17, 2025

Instead of the conventional [4+2] cycloaddition, a regioselective Schmittel-type [2+2] cycloaddition yne–allene esters, generated in situ from copper-catalyzed dediazotized coupling γ-alkynyl diazoacetates with terminal alkynes, is reported, enabling bicyclization process to produce diverse array C1-arylated cyclobuta[a]indenes moderate good yields. The protocol features wide functional group compatibility, mild reaction conditions, and experimental simplicity, holding significant potential for building new tricyclic cyclobutenes.

Language: Английский

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Gold‐Catalyzed Orthogonal and Chemocontrolled Synthesis of [4‐7‐6] Tricycles from 1,5‐Diynes

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: 366(17), P. 3683 - 3688

Published: June 20, 2024

Abstract We report a one‐pot cascade sequence catalyzed by gold starting from 1,5‐diynes and zwitterion (source of Tf 2 C=CH ), which allows the chemo‐, regio‐ stereoselective preparation cyclobutene‐fused [4‐7‐6] tricycles displays orthogonal reactivity 1,5‐diyne system, metal catalyst. Moreover, obtained tricyclic bis(triflyl)cyclobutenes [triflyl=(trifluoromethyl)sulfonyl] can be easily converted into more complex structures such as bridged ketal fused 1,3‐oxazine tetracyclic systems, demonstrating potential our protocol.

Language: Английский

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Fluoro-Promoted Thermal Ring Expansion of Cyclopropyl Carbenes to gem-Difluorinated Cyclobutenes

Organic Letters, Journal Year: 2024, Volume and Issue: 26(48), P. 10317 - 10321

Published: Nov. 21, 2024

Synthesis of

Language: Английский

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