Rational Design of Axially Chiral Styrene‐Based Organocatalysts and Their Application in Catalytic Asymmetric (2+4) Cyclizations

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 61(7)

Published: Nov. 30, 2021

A new class of axially chiral styrene-based thiourea tertiary amine catalysts, which have unique characteristics such as an efficient synthetic route, multiple elements, and activating groups, has been rationally designed. These catalysts proven to be organocatalysts, enabling the chemo-, diastereo-, enantioselective (2+4) cyclization 2-benzothiazolimines with homophthalic anhydrides in good yields (up 96 %) excellent stereoselectivities (all >95:5 dr, up 98 % ee). More importantly, theoretical calculations elucidated important role styrene moiety controlling both reactivity enantioselectivity. This work not only represents first design catalytic asymmetric 2-benzothiazolimines, but also gives in-depth understanding organocatalysts.

Language: Английский

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Catalytic Asymmetric Axially Chiral Allenyl C–P Bond Formation

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(28), P. 12619 - 12626

Published: July 8, 2022

Chiral organophosphorous compounds are very important in catalysis, organic syntheses, and medicinal chemistry. However, catalytic enantioselective protocols for the axially chiral allenyl phosphorus have never been reported. Herein, a palladium-catalyzed carbon–phosphorus bond formation reaction affording phosphonates has developed. The enjoys high yields ees accommodating wide range of functional groups. Mechanistic studies unveiled an overwhelming kinetic resolution process.

Language: Английский

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Enantioselective Synthesis of Spirosilabicyclohexenes by Asymmetric Dual Ring Expansion of Spirosilabicyclobutane with Alkynes

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(48)

Published: Oct. 7, 2022

Silaspiranes have attracted particular attention due to their chiral spiro-silicon center, which serves as an ideal carbon isostere and can endow spiro-analogs with distinct properties. Distinct from previously reported cyclization or cycloaddition strategies form 5/5-silaspiranes, we report herein the asymmetric dual ring expansion of spirosilabicyclobutanes alkynes synthesize axially spirosilabicyclohexenes bearing a novel 6/6-silaspirane framework. DFT (density functional theory) calculations provide deep insight into origin high enantioselectivity controlled by sterically demanding binaphthyl phosphoramidite ligand. Preliminary studies chiroptical properties indicate that one spirosilabicyclohexene analogs exhibit fluorescence emission, Cotton effects CPL (circularly polarized luminescence) activity.

Language: Английский

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Biomimetic asymmetric catalysis

Science China Chemistry, Journal Year: 2023, Volume and Issue: 66(6), P. 1553 - 1633

Published: April 25, 2023

Language: Английский

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SPSiPs, a Class of Diphosphine Ligands Based on SPSiOL with a Large Dihedral Angle

Organic Letters, Journal Year: 2023, Volume and Issue: 25(21), P. 3859 - 3863

Published: May 22, 2023

The development and the synthetic applications of a novel class diphosphine ligands (SPSiPs) based on chiral spirosilabiindane diol (SPSiOL) are presented. Starting from SPSiOL, could be readily prepared in three steps with high efficiency. This features rigid configuration, large dihedral angle, P-M-P long P-P distance. potentials SPSiPs asymmetric catalysis have also been preliminarily disclosed.

Language: Английский

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Chemodivergent and Enantioselective Synthesis of Spirobi[dihydrophenalene] Structures

Organic Letters, Journal Year: 2025, Volume and Issue: 27(3), P. 869 - 873

Published: Jan. 10, 2025

The development and enantioselective synthesis of two types C2-symmetric spirobi[dihydrophenalene] structures is reported. reaction proceeds via rhodium-catalyzed 2-fold asymmetric conjugate arylation dienones followed by BF3·OEt2-promoted spirocyclization to give the enantiopure spiro products. Additive-dependent chemodivergent 3,3'-diarylated 2,2',3,3'-tetrahydro-1,1'-spirobi[phenalene]-9,9'-diols (3,3'-Ar2-SPHENOLs) corresponding diary ethers from same intermediate achieved. structural properties 3,3'-Ph2-SPHENOL are analyzed, its application in catalysis has been preliminarily demonstrated.

Language: Английский

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Enantioselective Synthesis of Spiroketals and Spiroaminals via Gold and Iridium Sequential Catalysis

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(26)

Published: April 21, 2022

Abstract The enantioselective cascade reaction between racemic 2‐(1‐hydroxyallyl)phenols and alkynols/alkynamides was realized by using a gold iridium sequential catalytic system. In this procedure, the in situ generated exocyclic vinyl ethers or enamides undergo asymmetric allylation/spiroketalization with π‐ally‐Ir amphiphilic species, which provides an efficient straightforward access to spiroketals spiroaminals excellent enantioselectivities. Moreover, 2‐(1‐hydroxyallyl)anilines were also suitable along kinetic resolution process, affording enantioenriched good yields. synthetic utility of method has been demonstrated synthesis analogue Paecilospirone.

Language: Английский

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Asymmetric α‐Allylation of Glycinate with Switched Chemoselectivity Enabled by Customized Bifunctional Pyridoxal Catalysts

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(17)

Published: Feb. 19, 2022

Abstract Owing to the strong nucleophilicity of NH 2 group, free‐NH glycinates react with MBH acetates usually deliver N‐allylated products even in absence catalysts. Without protection chiral pyridoxal catalysts bearing an amide side chain at C3 position naphthyl ring switched chemoselectivity from intrinsic N‐allylation α‐C allylation. The reaction formed multisubstituted glutamic acid esters as S N 2′–S 2′ good yields excellent stereoselectivity (up 86 % yield, >20 : 1 dr, 97 ee). As compared arm C2 position, pyridoxals this study have a bigger catalytic cavity enable effective activation larger electrophiles, such and related intermediates. is proposed proceed via cooperative bifunctional catalysis pathway, which accounts for high level diastereo‐ enantiocontrol

Language: Английский

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Diastereo‐ and Enantioselective Synthesis of Bisbenzannulated Spiroketals and Spiroaminals by Ir/Ag/Acid Ternary Catalysis

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(42)

Published: Aug. 4, 2022

Abstract We reported herein an iridium/silver/acid ternary catalytic system to access bisbenzannulated [6,6]‐spiroketals in high efficiency with generally diastereo‐ and enantioselectivities (up >20 : 1 dr, >99 % ee). In this procedure, readily available o ‐alkynylacetophenones undergo cycloisomerization generate isochromenes situ that participate stereoselective allylation/spiroketalization sequence 2‐(1‐hydroxyallyl)phenols. Meanwhile, 2‐(1‐hydroxyallyl)anilines were also compatible cascade reaction, furnishing structurally novel [6,6]‐spiroaminals good diastereoselectivities (8 1–12 dr) excellent (98 %–>99 Moreover, experimental studies theoretical calculations performed illustrate the reaction mechanism stereochemistry.

Language: Английский

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Lead-halide perovskite quantum dots embedded in mesoporous silica as heterogeneous photocatalysts combined with organocatalysts for asymmetric catalysis

Green Chemistry, Journal Year: 2024, Volume and Issue: 26(10), P. 6068 - 6077

Published: Jan. 1, 2024

CsPbBr 3 quantum dots embedded in KIT-6 to form silica-shell-protected heterogeneous photocatalysts, which were further combined with chiral organocatalysts forming dual-catalysts explore the activity and stereoselectivity asymmetric catalysis.

Language: Английский

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