Synergistic Photoenzymatic Catalysis Enables Synthesis of a-Tertiary Amino Acids Using Threonine Aldolases

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(20), С. 13754 - 13759

Опубликована: Май 13, 2024

a-Tertiary amino acids are essential components of drugs and agrochemicals, yet traditional syntheses step-intensive provide access to a limited range structures with varying levels enantioselectivity. Here, we report the α-alkylation unprotected alanine glycine by pyridinium salts using pyridoxal (PLP)-dependent threonine aldolases Rose Bengal photoredox catalyst. The strategy efficiently prepares various a-tertiary in single chemical step as enantiomer. UV–vis spectroscopy studies reveal ternary interaction between salt, protein, photocatalyst, which hypothesize is responsible for localizing radical formation active site. This method highlights opportunity combining catalysts enzymes new catalytic functions known enzymes.

Язык: Английский

---

Desymmetrization–Addition Reaction of Cyclopropenes to Imines via Synergistic Photoredox and Cobalt Catalysis

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(28), С. 18892 - 18898

Опубликована: Июль 5, 2024

Herein, we designed a reaction for the desymmetrization-addition of cyclopropenes to imines by leveraging synergy between photoredox and asymmetric cobalt catalysis. This protocol facilitated synthesis series chiral functionalized cyclopropanes with high yield, enantioselectivity, diastereoselectivity (44 examples, up 93% yield >99% ee). A possible mechanism involving cyclopropene desymmetrization Co-H species imine addition Co-alkyl was proposed. study provides novel route important extends frontier metallaphotoredox

Язык: Английский

---

CoH-catalyzed asymmetric remote hydroalkylation of heterocyclic alkenes: a rapid approach to chiral five-membered S- and O-heterocycles

Chemical Science, Год журнала: 2024, Номер 15(23), С. 8888 - 8895

Опубликована: Янв. 1, 2024

A highly efficient method achieves precise construction of alkyl chiral centers at remote C3-positions in five-membered S/O-heterocycles via cobalt-catalyzed asymmetric hydroalkylation heterocyclic alkenes.

Язык: Английский

---

Harnessing the potential of acyl triazoles in bifunctional cobalt-catalyzed radical cross-coupling reactions

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Авг. 13, 2024

Persistent radicals facilitate numerous selective radical coupling reactions. Here, we have identified acyl triazole as a new and versatile moiety for generating persistent intermediates through single-electron transfer processes. The efficient generation of these is facilitated by the formation substrate-coordinated cobalt complexes, which subsequently engage in cross-coupling Remarkably, triazole-coordinated complexes exhibit metal-hydride hydrogen atom (MHAT) capabilities with alkenes, enabling synthesis diverse ketone products without need external ligands. By leveraging effect, this catalytic approach also allows development other reactions two representative precursors. discovery triazoles effective substrates ligands catalysis, combined bifunctional nature system, opens up avenues design sustainable organic transformations. radical-mediated has emerged powerful tool forging C–C bonds. authors identify processes, context cobalt-catalysed carbon-carbon couplings under photoirradiation.

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

---

A General Enantioselective α-Alkyl Amino Acid Derivatives Synthesis Enabled by Cobalt-Catalyzed Reductive Addition

Journal of the American Chemical Society, Год журнала: 2024, Номер unknown

Опубликована: Сен. 12, 2024

Enantioenriched unnatural amino acids represent a prevalent motif in organic chemistry, with profound applications biochemistry, medicinal and materials science. Herein, we report cobalt-catalyzed aza-Barbier reaction of dehydroglycines unactivated alkyl halides to afford α-amino esters high enantioselectivity. This catalytic reductive alkylative addition protocol circumvents the use moisture-, air-sensitive organometallic reagents, stoichiometric chiral auxiliaries, enabling conversion variety primary, secondary, even tertiary α-alkyl-amino under mild conditions, thus leading broad functional group tolerance. The expedient access biologically active motifs demonstrates practicality this by reducing number synthetic steps enhancing efficiency.

Язык: Английский

---

Catalytic Asymmetric Barbier Reaction of Ketones with Unactivated Alkyl Electrophiles

Journal of the American Chemical Society, Год журнала: 2024, Номер unknown

Опубликована: Окт. 3, 2024

The Barbier reaction is a reductive-type addition of an aldehyde or ketone with organic electrophile in the presence terminal metal reductant, providing straightforward and efficient method for carbon-carbon bond formation. This possesses advantage circumventing preparation moisture- air-sensitive organometallic reagents. However, catalytic ketones to construct tetrasubstituted stereogenic centers largely underdeveloped, despite its great potential accessing synthetically challenging chiral tertiary alcohol. Particularly, leveraging unactivated alkyl electrophiles as coupling components still rarely exploited. Herein, we disclose photoredox-assisted cobalt-catalyzed asymmetric alkylative Barbier-type address aforementioned challenges, thereby allowing construction highly congested carbon centers. fragments could be either readily accessible halides redox-active esters generated through decarboxylative pathway. Both types include primary, secondary, ones, thus affording diverse enantioenriched alcohols broad substrate scope. enantioselective protocol applied expedient synthesis core structure

Язык: Английский

---

Research Progress in the Synthesis of α-Tertiary Amines via Radical Strategies

Chinese Journal of Organic Chemistry, Год журнала: 2025, Номер 45(1), С. 22 - 22

Опубликована: Янв. 1, 2025

Язык: Английский

---

Photo‐Promoted Nitrogen‐Centered Radical Mediated Intermolecular Aminative Carbonylation of Tertiary Allyl Alcohols to Access β‐Amino Ketones through (Hetero)Aryl Migration

ChemistryEurope, Год журнала: 2025, Номер unknown

Опубликована: Март 12, 2025

Abstract Carbon monoxide, as a crucial C1 synthon, has been widely used in the difunctionalization of alkenes. Additionally, nitrogen‐centered radicals (NCRs) are also effective intermediates for constructing C−N bonds. Herein, radical‐mediated aminative carbonylation strategy producing β ‐amino ketones from tertiary allyl alcohols disclosed. Good yields with different functional groups were generated effectively under light irradiation.

Язык: Английский

---

Photoredox/Palladium-Catalyzed Reduction Alkylation of Imines and Ammonium Salts via Dual C–N Bond Cleavage

The Journal of Organic Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Апрель 16, 2025

Here, we report a photoredox/palladium-catalyzed reduction alkylation of imines and ammonium salts via dual C-N cleavage. This reaction proceeds under mild, green, operationally simple conditions, offering broad scope secondary amine compounds with alpha quaternary carbon. Mechanistic studies indicate that the α-amino carbanion, generated by successive single-electron transfer process, is key intermediate in photoredox/palladium catalysis.

Язык: Английский

---