P-Stereogenic Phosphorus Ligands in Asymmetric Catalysis

Chemical Reviews, Год журнала: 2024, Номер 124(14), С. 8657 - 8739

Опубликована: Июль 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.

Язык: Английский

---

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

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(39), С. 21152 - 21158

Опубликована: Сен. 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.

Язык: Английский

---

Palladium-Catalyzed Divergent Enantioselective Functionalization of Cyclobutenes

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(18), С. 12691 - 12701

Опубликована: Апрель 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.

Язык: Английский

---

Polyethylene Materials with Tunable Degradability by Incorporating In-Chain Mechanophores

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(34), С. 24024 - 24032

Опубликована: Авг. 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.

Язык: Английский

---

Cobalt‐Catalyzed Enantioselective Alkenylation of Aldehydes

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(33)

Опубликована: Май 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.

Язык: Английский

---

Strain-Inducing Positional Alkene Isomerization

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(36), С. 20053 - 20061

Опубликована: Авг. 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.

Язык: Английский

---

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

ChemCatChem, Год журнала: 2023, Номер 16(1)

Опубликована: Ноя. 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.

Язык: Английский

---

Ring‐Opening Cross‐Coupling/Cyclization Reaction of Cyclopropanols with Organic Compounds

ChemistrySelect, Год журнала: 2023, Номер 8(32)

Опубликована: Авг. 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.

Язык: Английский

---

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

ACS Catalysis, Год журнала: 2024, Номер 14(3), С. 1505 - 1513

Опубликована: Янв. 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.

Язык: Английский

---

Regio- and Enantioselective Hydromethylation of 3-Pyrrolines and Glycals Enabled by Cobalt Catalysis

JACS Au, Год журнала: 2024, Номер 4(6), С. 2312 - 2322

Опубликована: Июнь 11, 2024

Enantioenriched 3-methylpyrrolidine, with its unique chiral nitrogen-containing core skeleton, exists widely in various functional molecules, including natural products, bioactive compounds, and pharmaceuticals. Traditional methods for synthesizing these valuable methyl-substituted heterocycles often involve enzymatic processes or complex procedures auxiliaries, limiting the substrate scope efficiency. Efficient catalytic methylation, especially an enantioselective manner, has been a long-standing challenge chemical synthesis. Herein, we present novel approach remote stereoselective installation of methyl group onto N-heterocycles, leveraging CoH-catalyzed asymmetric hydromethylation strategy. By effectively combining commercial cobalt precursor modified bisoxazoline (BOX) ligand, variety easily accessible 3-pyrrolines can be converted to enantiopure 3-(isotopic labeling)methylpyrrolidine compounds outstanding enantioselectivity. This efficient protocol streamlines two-step synthesis enantioenriched which previously required up five six steps under harsh conditions expensive starting materials.

Язык: Английский

---