P-Stereogenic Phosphorus Ligands in Asymmetric Catalysis

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

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Cobalt‐Catalyzed Asymmetric Aza‐Nozaki–Hiyama–Kishi (NHK) Reaction of α‐Imino Esters with Alkenyl Halides

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(7)

Published: Jan. 2, 2024

Chromium-catalyzed enantioselective Nozaki-Hiyama-Kishi (NHK) reaction represents one of the most powerful approaches for formation chiral carbon-heteroatom bond. However, construction sterically encumbered tetrasubstituted stereocenter through NHK still posts a significant challenge. Herein, we disclose cobalt-catalyzed aza-NHK ketimine with alkenyl halide to provide convenient synthetic approach manufacture enantioenriched α-vinylic amino acid. This protocol exhibits excellent functional group tolerance 99 % ee in cases. Additionally, this asymmetric reductive method is also applicable aldimine access trisubstituted stereogenic centers.

Language: Английский

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

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(28), P. 18892 - 18898

Published: July 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

Language: Английский

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Enantioselective Reductive (Hetero)Arylation of Cyclic N‐Sulfonyl Imines by Cobalt Catalysis

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(19)

Published: March 14, 2023

Transition-metal-catalyzed enantioselective addition of aryl organometallic reagents to imines has emerged as one the most powerful tools for formation optically active diarylmethylamines. Here, we report first asymmetric reductive (hetero)arylations using and heteroaryl halides enabled by a chiral cobalt-bisphosphine catalyst. This approach shows good functional group compatibility complements reported strategy without use reagents. Mechanistic investigations supported that aryl-cobalt, instead an arylzinc reagent, was formed in situ this aryl-addition event.

Language: Английский

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Cobalt‐Catalyzed Enantioselective Reductive α‐Chloro‐Carbonyl Addition of Ketimine to Construct the β‐Tertiary Amino Acid Analogues

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(25)

Published: Jan. 22, 2024

β-Tertiary amino acid derivatives constitute one of the most frequently occurring units in natural products and bioactive molecules. However, efficient asymmetric synthesis this motif still remains a significant challenge. Herein, we disclose cobalt-catalyzed enantioselective reductive addition reaction ketimine using α-chloro carbonyl compound as radical precursor, providing expedient access to diverse array enantioenriched β-quaternary analogues. This protocol exhibits outstanding enantioselectivity broad substrate scope with excellent functional group tolerance. Preliminary mechanism studies rule out possibility Reformatsky-type confirm involvement species stereoselective process. The synthetic utility has been demonstrated through rapid assembly iterative oligopeptide, showcasing its versatile platform for late-stage modification drug candidates.

Language: Английский

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Photoinduced Pd-Catalyzed Dearomative 2,5-Difunctionalizition of Furans via Cascade C–C/C–O Bond Formation

Organic Letters, Journal Year: 2024, Volume and Issue: 26(5), P. 1083 - 1087

Published: Jan. 26, 2024

We report an efficient and mild approach for radical dearomatization via photoinduced palladium-catalyzed reaction of three components (i.e., furans, alcohols, bromoalkanes). In this strategy, various functionalized spiro-heterocycles were prepared from furans in one step cascade C–C/C–O bond formation under redox neutral conditions.

Language: Английский

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Cobalt-Catalyzed Asymmetric Reductive Alkenylation and Arylation of Heterobiaryl Tosylates: Kinetic Resolution or Dynamic Kinetic Resolution?

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(49), P. 26747 - 26755

Published: Nov. 29, 2023

Herein, we report a cobalt-catalyzed atroposelective reductive cross-coupling of racemic heterobiaryl tosylates with C(sp2)–X type electrophile. Both aryl and alkenyl halides are competent precursors for this reaction, providing variety heterobiaryls as the products in highly enantioselective manner high functionality tolerance. The related asymmetric arylation alkenylation discovered to proceed divergent mechanisms. reaction pathway changes from kinetic resolution (KR) when bromides iodides bearing strong electron-withdrawing substitution on para-position employed starting materials an enantioconvergent transformation via dynamic KR configurationally labile cobaltacycles relatively electron-rich used. change mechanisms turns out arise relative rates two competing elementary steps, which epimerization cyclic Co(I) intermediates their trapping by coupling electrophiles C(sp2)-type oxidative addition.

Language: Английский

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Selective Synthesis of Pyrazolonyl Spirodihydroquinolines or Pyrazolonyl Spiroindolines under Aerobic or Anaerobic Conditions

Organic Letters, Journal Year: 2022, Volume and Issue: 24(51), P. 9473 - 9478

Published: Dec. 16, 2022

Presented herein is a condition-controlled selective synthesis of pyrazolonyl spirodihydroquinolines or spiroindolines through formal [5 + 1] [4 spiroannulation 2-alkenylanilines with diazopyrazolones. Mechanistically, the formation title products involves initial generation spiro-fused seven-membered ruthenacycle species serving as key intermediate Ru(II)-catalyzed C-H/N-H bonds metalation, carbene formation, and its migratory insertion. When reaction carried out under air, undergoes reductive elimination to afford spirodihydroquinoline. run argon, protonation intramolecular nucleophilic addition furnish spiroindoline. This work provides an atom-economical protocol for effective functionalization alkenyl C(sp2)-H bond, allowing rapid assembly valuable spiroscaffolds broad range substrates.

Language: Английский

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Recent Advances in the Synthesis of Indolines via Dearomative Annulation of N‐acylindoles

Asian Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 11(10)

Published: Aug. 3, 2022

Abstract Polycyclic fused indoline derivatives, specifically those bearing tertiary or quaternary carbon stereocenters at C2 and C3 positions, stand as an important class of nitrogen‐containing heterocyclic compounds because they are frequently occurring core structures in a wide variety alkaloid natural products, pharmaceutical molecules, functional materials. Over the past few decades, development new versatile synthetic approaches for construction indolines has been focus great deal research initiatives. In this review, recent advances dearomative annulation N‐ acylindoles with diverse nucleophiles summarized since 2012, which could be divided into five categories: 1) Dearomative Heck reactions acylindoles; 2) Visible‐light‐induced reductive dearomatization 3) Lewis acid‐catalyzed 4) Asymmetric 5) by other closely related reagents.

Language: Английский

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Dearomatization of Biaryls through Polarity Mismatched Radical Spirocyclization

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 62(6)

Published: Dec. 1, 2022

Dearomatization reactions involving radical cyclizations can facilitate the synthesis of complex polycyclic systems that find applications in medicinal chemistry and natural product synthesis. Here we employ redox-neutral photocatalysis to affect a spirocyclization transforms biaryls into spirocyclic cyclohexadienones under mild reaction conditions. In departure from previously reported methods, our work demonstrates polarity mismatched addition nucleophilic an electron rich arene, allows regioselective 2,4- or 2,5-cyclohexadienones with broad functional group tolerance. By transforming spirocycles, methodology accesses underexplored three-dimensional chemical space, provides efficient means creating quaternary spirocenters apply first cytotoxic plant metabolite denobilone A.

Language: Английский

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