A Remarkable Influence of La(III)/N,N′-Dioxide Structure on Asymmetric Formal Substitution of 3-Bromo-3-substituted Oxindoles with TMSCN

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(5), P. 2908 - 2916

Published: Feb. 10, 2024

The structural elucidation of chiral rare-earth-based catalysts in asymmetric reactions holds significant importance as it is crucial for comprehending their operational mechanisms and broadening applications the realm synthesis. Herein, a LaIII/(L3-RaMe3)2 complex was identified to be more active enantioselective than LaIII/L3-RaMe3 formal substitution racemic 3-bromo-3-substituted oxindoles with TMSCN. experimental studies theoretical calculations disclosed that partial dissociation N,N′-dioxide ligand involved catalytic process LaIII/(L3-RaMe3)2. These insights provided rationale remarkable effect catalyst structures on results nonlinear observed current reaction system. This protocol offers straightforward efficient pathway synthesize various 3-cyano-3-substituted (53 examples, up 99% yield, 98% ee). In addition, synthesis bioactive compound CRTH2 receptor antagonist obvious inhibitory several products viability cancer cells demonstrate potential utility this methodology.

Language: Английский

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Stereodivergent Construction of 3,3′-Disubstituted Oxindoles via One-Pot Sequential Allylation/Alkylation and Its Application to the Total Synthesis of Trigolute B and D

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 27, 2025

The absolute and relative configurations of bioactive chiral molecules are typically relevant to their biological properties. It is thus highly important desirable construct all possible stereoisomers a lead candidate or given natural compound. Synergistic dual catalysis has been recognized as reliable synthetic strategy for variety predictable stereodivergent transformations. Despite the impressive progress made in this field, carbon-carbon bond-formation reactions involving stabilized nucleophiles remain elusive. Herein, we report an iridium- magnesium-catalyzed one-pot sequential allylic alkylation/nucleophilic alkylation cascade process synthesis four 3,3'-disubstituted oxindoles through three-component reaction. A diverse array products readily prepared with high functional group compatibility good yields excellent diastereo- enantioselectivities. Subsequently, total spirooxindole alkaloid trigolutes B D accomplished concise unified route using same set starting materials.

Language: Английский

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Quinone-Initiated Photocatalytic Enantioselective Giese Radical Addition with Ethers, Thioethers, Amines, and Alkanes

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(16), P. 12031 - 12041

Published: July 29, 2024

Photocatalytic enantioselective Giese radical addition with inert C(sp3)–H bonds represents a highly efficient and economically favorable approach to synthesizing diverse value-added chiral molecules from abundant feedstock. Herein, we disclose quinone-initiated photocatalytic asymmetric of α-substituted acrylamides by applying simple quinones as HAT photocatalysts in combination N,N′-dioxide/praseodymium(III) catalyst. A wide array ethers, thioethers, selenide, amines, alkanes can smoothly transform into the corresponding α-aryl amide derivatives satisfactory enantioselectivities (68 examples, up 95% ee) under mild conditions. Based on spectroscopy studies control experiments, catalytic cycle was proposed, DFT calculations revealed that interaction between quinone Lewis acid essential for enantio-induction back hydrogen atom transfer process.

Language: Английский

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A Route to the Mild Synthesis of α-Selenomethylketones via Vinyl Azides

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: March 27, 2025

Organic selenium compounds are important molecules with a wide range of applications in pharmaceuticals, organic materials, catalysis, and other fields. Herein, we report the synthesis α-selenomethylketones through reaction vinyl azides arylselenols benzylselenol. This protocol has advantages releasing only nitrogen as benign byproduct, using air an environmentally friendly initiator, very short duration, mild conditions, broad substrate compatibility. The results exploratory studies show that oxygen is used initiator to promote this radical cascade reaction.

Language: Английский

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Catalytic Asymmetric Synthesis of Axially and Centrally Chiral 1,2-Dihydrobenzofuro[3,2-b]pyridines through a [2 + 2] Cycloaddition/Retroelectrocyclization/Re-Cycloaddition Cascade

Organic Letters, Journal Year: 2023, Volume and Issue: 25(44), P. 8005 - 8009

Published: Oct. 31, 2023

A catalytic asymmetric tandem cyclization of azadienes and ortho-alkynylnaphthols accelerated by the chiral N,N′-dioxide-gadolinium(III) complex is disclosed. This method allows synthesis a range 1,2-dihydrobenzofuro[3,2-b]pyridines containing both axially centrally elements in high yields excellent stereoselectivities (up to >99% yield, 91:9 dr, 98% ee). control experiment revealed that this process proceeded through multistep [2 + 2] cycloaddition/retroelectrocyclization/tautomerism/1,6-conjugate addition cascade.

Language: Английский

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