Domino Reaction for the Synthesis of Substituted Pyrano[3′,4′:3,4]cyclopenta[1,2-c]chromenes Involving Double Ring Formation DOI
Abdolali Alizadeh,

Azar Rostampoor

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(21), P. 15739 - 15748

Published: Oct. 16, 2024

Herein, we present a green cascade approach for synthesizing range of chemoselective polysubstituted pyrano[3′,4′:3,4]cyclopenta[1,2-c]chromenes containing chiral stereocenter. The strategy involves metal-free nucleophilic reaction between dialkyl (2E)-2-{2-oxo-3-[(2E)-3-aryl-2-propenoyl]-2H-chromen-4-yl}-2-butenedioates and α,α-dicyanoolefins under reflux conditions in ethanol solvent. Mechanistic studies have shown that the proceeds via steps, including Michael addition, intramolecular C- O-cyclization, trans-esterification, [1,2]-H [1,5]-methoxy- ethoxy carbonyl shift, finally aromatization to yield desired product. In this method, three bonds (2C–C C–O) form one pot, simultaneously forming two new cyclopentane pyrano rings by double cyclization reactions. Other advantages method are it has simple operation, readily available starting materials, process, transition metal-free, synthetically useful yields, using as

Language: Английский

P-Stereogenic Phosphorus Ligands in Asymmetric Catalysis DOI
Tsuneo Imamoto

Chemical Reviews, Journal Year: 2024, Volume and Issue: 124(14), P. 8657 - 8739

Published: July 2, 2024

Chiral phosphorus ligands play a crucial role in asymmetric catalysis for the efficient synthesis of useful optically active compounds. They are largely categorized into two classes: backbone chirality and P-stereogenic ligands. Most reported belong to former class. Privileged ones such as BINAP DuPhos frequently employed wide range catalytic transformations. In contrast, latter class has remained small family many years mainly because their synthetic difficulty. The late 1990s saw emergence novel with superior enantioinduction ability Rh-catalyzed hydrogenation reactions. Since then, numerous have been synthesized used This Review summarizes thus far, including stereochemical electronic properties that afford high excellent enantioselectivities. Examples reactions use this described together applications construction key intermediates natural products therapeutic agents. literature covered dates back 1968 up until December 2023, centering on studies published later years.

Language: Английский

Citations

39
Enantioselective Synthesis of Chiral Cyclobutenes Enabled by Brønsted Acid-Catalyzed Isomerization of BCBs DOI

Si-Li Lin,

Ye‐Hui Chen, Huanhuan Liu

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(39), P. 21152 - 21158

Published: Sept. 21, 2023

Chiral cyclobutene units are commonly found in natural products and biologically active molecules. Transition-metal-catalysis has been extensively used asymmetric synthesis of such structures, while organocatalytic approaches remain elusive. In this study, bicyclo[1.1.0]butanes involved enantioselective transformation for the first time to offer a highly efficient route toward cyclobutenes with good regio- enantiocontrol. The utilization N-triflyl phosphoramide as chiral Brønsted acid promoter enables isomerization process proceed under mild conditions low catalyst loading well functional group compatibility. resulting could serve platform molecules downstream manipulations excellent reservation stereochemical integrity, demonstrating synthetic practicality developed method. Control experiments have also performed verify formation key carbocation intermediate at benzylic position.

Language: Английский

Citations

40
Polyethylene Materials with Tunable Degradability by Incorporating In-Chain Mechanophores DOI
Xiaohui Zhang, Yajun Zhao, Meng Chen

et al.

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(34), P. 24024 - 24032

Published: Aug. 17, 2024

Polyolefins are recognized as fundamental plastic materials that manufactured in the largest quantities among all synthetic polymers. The chemical inertness of saturated hydrocarbon chains is crucial for storing and using polyolefin plastics, but poses significant environmental challenges related to pollution. Here, we report a versatile approach creating polyethylene with tunable degradability by incorporating in-chain mechanophores. Through palladium-catalyzed coordination/insertion copolymerization ethylene cyclobutene-fused comonomers, several cyclobutane-fused mechanophores were successfully incorporated varied insertion ratios (0.35-26 mol %). resulting exhibit both high thermal stability remarkable acid resistance. Upon mechanochemical activation ultrasonication or ball-milling, degradable functional units (imide ester groups) introduced into main polymer chain. synergy hydrolysis facilitates efficient degradation molecular weight telechelic oligomers.

Language: Английский

Citations

10
Palladium-Catalyzed Divergent Enantioselective Functionalization of Cyclobutenes DOI

Zhonggui Wang,

Jie Zhu, Minyan Wang

et al.

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(18), P. 12691 - 12701

Published: April 27, 2024

Aliphatic strained rings have been increasingly applied in medicinal chemistry due to their beneficial physicochemical and pharmacokinetic properties. However, the divergent synthesis of enantioenriched cyclobutane derivatives with various structural patterns continues be a significant challenge. Here, we disclose palladium-catalyzed enantioselective desymmetrization cyclobutenes, resulting series hydroarylation 1,2- 1,3-diarylation products via interceptions common Heck intermediate. Mechanistic investigations provide valuable insights into understanding catalytic mode palladium catalysts observed variations deuterium-responsive behavior during reactions. Furthermore, synthetic utility is demonstrated syntheses deuterated drug candidate belaperidone skeletons pseudosymmetrical truxinic acid-type derivatives.

Language: Английский

Citations

9
Cobalt‐Catalyzed Enantioselective Alkenylation of Aldehydes DOI

Chuiyi Lin,

Jiwu Zhang,

Zhao Sun

et al.

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(33)

Published: May 31, 2024

Catalytic enantioselective alkenylation of aldehydes with easily accessible alkenyl halides promoted by a chiral cobalt complex derived from newly developed tridentate bisoxazolinephosphine is presented. Such processes represent an unprecedented reaction pathway for catalysis and general approach that enable rapid construction highly diversified enantioenriched allylic alcohols containing 1,1-, 1,2-disubstituted trisubstituted alkene as well axial stereogenicity in up to 99 % yield : 1 er without the need preformation alkenyl-metal reagents. DFT calculations revealed origin enantioselectivity.

Language: Английский

Citations

9
Cobalt‐Catalyzed Hydroalkylation of Alkenes and Alkynes: Advantages and Opportunities DOI

Bingxue Liu,

Qiang Liu

ChemCatChem, Journal Year: 2023, Volume and Issue: 16(1)

Published: Nov. 3, 2023

Abstract Sp3‐hybridized carbons‐rich molecules play a crucial role in drug discovery. Cobalt‐catalyzed hydroalkylation of alkenes and alkynes is an efficient method to synthesize these compounds. These reactions exhibit wide range applicability high tolerance for functional groups, utilizing readily available instead hyperactive metallic reagents. Herein, we summarize the advancements cobalt‐catalyzed alkynes, according different reaction mechanisms. We present detailed discussion scope limitations, plausible mechanisms opportunities further development.

Language: Английский

Citations

13
Regio- and Diastereoselective Highly Strained Alkylidenecyclobutane Isomerization/Hydroacylation: Synthesis of Multisubstituted Cyclobutanes with Consecutive Stereocenters DOI

Kai-Qiang Tian,

Shi‐Jiao Zhang,

Jun Zhao

et al.

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(3), P. 1505 - 1513

Published: Jan. 16, 2024

The regio- and diastereoselective alkene isomerization hydrofunctionalization sequence enabled by transition-metal complexes allows rapid activation assembly of the C(sp3)–H bond that is either adjacent or distal to initial double bond, which has been a longstanding challenge in this field. Herein, we develop unusual rhodium-catalyzed alkylidenecyclobutanes with subsequent hydroacylation reaction provide multisubstituted cyclobutanes continuous stereocenters. Note tandem process features good diastereoselectivity profile. Isotopic labeling experiments support "exo endo" migration coordinated cyclobutene responsible for deuterium incorporation observed cyclobutane product.

Language: Английский

Citations

5
Strain-Inducing Positional Alkene Isomerization DOI
Vignesh Palani, Alison E. Wendlandt

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(36), P. 20053 - 20061

Published: Aug. 30, 2023

Small, strained ring systems are important pharmacophores in medicinal chemistry and versatile intermediates organic synthesis. However, the kinetic thermodynamic instability of many molecules renders them challenging to prepare. Here, we report a strain-inducing positional alkene isomerization reaction that provides mild selective access cyclobutene building blocks from readily obtained cyclobutylidene precursors. This endergonic relies on sequential synergistic action decatungstate polyanion photocatalyst cobaloxime co-catalyst store potential energy form strain. The versatility products is demonstrated through diverse subsequent strain-releasing transformations. Mechanistic studies reveal steric basis for strain-selective product formation.

Language: Английский

Citations

12
Ring‐Opening Cross‐Coupling/Cyclization Reaction of Cyclopropanols with Organic Compounds DOI
Fatemeh Doraghi,

Seyedeh Pegah Aledavoud,

Azadeh Fakhrioliaei

et al.

ChemistrySelect, Journal Year: 2023, Volume and Issue: 8(32)

Published: Aug. 23, 2023

Abstract Cyclopropanols, due to their particular chemistry, can participate in various synthetic reactions with retention or cleavage of the strained three‐membered ring. Direct cross‐coupling ring‐opening reaction such molecules access organic compounds, as ketones has great importance medicinal chemistry and material sciences. Hence, coupling reaction/cyclization cyclopropanols for constructing new valuable presence a transition metal catalyst under metal‐free conditions is described this context. The features are discussed, mechanisms challenging highlighted.

Language: Английский

Citations

11
Photoredox cobalt-catalyzed asymmetric desymmetric reductive coupling of cyclobutenes with alkynes DOI Creative Commons

Tianlong Zeng,

Yezeng He, Ying Li

et al.

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: April 1, 2025

Catalytic methods to couple alkynes and alkenes are highly valuable in synthetic chemistry. The cobalt-catalyzed intermolecular reductive coupling of is particularly attractive due the unique reactivity cost-effectiveness cobalt catalysts. However, enantioselective transformations this kind less developed. limited successful examples restricted use electronically biased activated olefins as partners. Herein, we report an asymmetric desymmetric unbiased succinimide-containing cyclobutenes with synthesize enantioenriched, synthetically important vinyl cyclobutanes via photoredox dual catalysis. Excellent enantioselectivities, good diastereoselectivities regioselectivities obtained. Preliminary mechanistic studies suggest that Hantzsch ester a better reducing reagent when used combination Et3N. Density functional theory calculations reveal reaction proceeds more likely through Co(III)-H migratory insertion mechanism. Here, authors internal

Language: Английский

Citations

0