Mechanism-Guided Development of Transition-Metal-Catalyzed C–N Bond-Forming Reactions Using Dioxazolones as the Versatile Amidating Source

Accounts of Chemical Research, Journal Year: 2021, Volume and Issue: 54(11), P. 2683 - 2700

Published: May 12, 2021

ConspectusCatalytic reactions that construct carbon–nitrogen bonds are one of central themes in both synthetic and medicinal chemistry since the obtainable nitrogen-containing motifs commonly encountered natural products have also seen a growing prominence as key structural features marketed drugs preclinical candidates. Pd-catalyzed cross-couplings, such Buchwald–Hartwig amination, at forefront methods practical settings. However, they require prefunctionalized substrates (hetero)aryl halides must be prepared independently, often by multiple operations. One emerging way to circumvent these preparatory steps directly convert ubiquitous C–H into valuable C–N is catalytic which allows chemists devise shorter more efficient retrosynthetic schemes. The past two decades witnessed considerable progress expanding repertoire this strategy, especially identifying effective amino group precursors. In context, dioxazolones experienced dramatic resurgence recent years versatile nitrogen source combination with transition-metal catalyst systems facilitate decarboxylation access metal-acylnitrenoid intermediates. addition their high robustness easy accessibility from abundant carboxylic acids, unique reactivity transient intermediates amido transfer has led fruitful journey for mild amidation reactions.This Account summarizes our contributions development bond-forming using nitrenoid precursors, categorized subsets according mechanistic differences: inner- versus outer-sphere pathways. first section describes how we could unveil potential realm inner-sphere amidation, where demonstrated serve not only manageable alternatives acyl azides but highly reagents significantly reduce loading temperature. Taking advantage conditions 9 Cp*M complexes (M = Rh, Ir, Co) or isoelectronic Ru species, dramatically expanded accessible scope. Mechanistic investigations revealed putative metal-nitrenoid species involved intermediate during catalysis, leads facile bond formation. On basis underpinning, succeeded developing novel platforms harness intermediacy metal-nitrenoids explore insertion via an pathway. Indeed, tailored catalysts were capable suppressing competitive Curtius-type decomposition, thus granting lactam products. We further repurposed upon modification chelating ligands identity transition metal achieve three goals: (i) addressing selectivity issues control regio-, chemo-, enantioselectivities, (ii) sustainable catalysis first-low metals, (iii) navigating chemical space (di)functionalization alkenes/alkynes. Together own research efforts, highlighted herein some important relevant advances other groups. finally conclude brief overview eye toward developments.

Language: Английский

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Nitrene transfer catalysts for enantioselective C–N bond formation

Nature Reviews Chemistry, Journal Year: 2021, Volume and Issue: 5(8), P. 580 - 594

Published: June 28, 2021

Language: Английский

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Chiral Carboxylic Acid Assisted Enantioselective C–H Activation with Achiral Cp^xM^III (M = Co, Rh, Ir) Catalysts

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(11), P. 6455 - 6466

Published: May 17, 2021

Enantioselective C–H functionalization is a powerful tool for synthesizing chiral molecules. In the past few years, combination of high-valent group 9 metals with achiral Cpx ligands and carboxylic acids (CCA) has emerged as promising catalytic system to enable selective cleavage enantiotopic bonds. This Perspective summarizes background, catalyst design, applied reactions in detail, followed by discussion future directions.

Language: Английский

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Rhodium-Catalyzed Asymmetric C–H Functionalization Reactions

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(16), P. 10079 - 10134

Published: Aug. 1, 2023

This review summarizes the advancements in rhodium-catalyzed asymmetric C–H functionalization reactions during last two decades. Parallel to rapidly developed palladium catalysis, rhodium catalysis has attracted extensive attention because of its unique reactivity and selectivity reactions. In recent years, Rh-catalyzed have been significantly many respects, including catalyst design, reaction development, mechanistic investigation, application synthesis complex functional molecules. presents an explicit outline catalysts ligands, mechanism, scope coupling reagents, applications.

Language: Английский

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Oxygen‐Linked Cyclopentadienyl Rhodium(III) Complexes‐Catalyzed Asymmetric C−H Arylation of Benzo[h]quinolines with 1‐Diazonaphthoquinones

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(28), P. 15510 - 15516

Published: April 16, 2021

Abstract Chiral cyclopentadienyl rhodium (CpRh) complex‐catalyzed asymmetric C−H functionalization reactions have witnessed a significant progress in organic synthesis. In sharp contrast, the reported chiral Cp ligands are limited to C‐linked and often synthetically challenging. To address these issues, we developed novel class of tunable bearing oxygen linkers, which were efficient catalysts for arylation benzo[ h ]quinolines with 1‐diazonaphthoquinones, affording axially heterobiaryls excellent yields enantioselectivity (up 99 % yield, 98.5:1.5 er). Mechanistic studies suggest that reaction is likely proceed by electrophilic activation, followed coupling cyclometalated rhodium(III) complex 1‐diazonaphthoquinones.

Language: Английский

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Enantioselective Aziridination of Unactivated Terminal Alkenes Using a Planar Chiral Rh(III) Indenyl Catalyst

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(2), P. 1447 - 1454

Published: Jan. 3, 2024

Chiral aziridines are important structural motifs found in natural products and various target molecules. They serve as versatile building blocks for the synthesis of chiral amines. While advances catalyst design have enabled robust methods enantioselective aziridination activated olefins, simple abundant alkyl-substituted olefins pose a significant challenge. In this work, we introduce novel approach utilizing planar rhodium indenyl to facilitate unactivated alkenes. This transformation exhibits remarkable degree functional group tolerance displays excellent chemoselectivity favoring alkenes over their counterparts, delivering wide range enantioenriched high-value aziridines. Computational studies unveil stepwise mechanism which alkene migratory insertion plays central role. process results formation strained four-membered metallacycle serves both enantio- rate-determining steps overall reaction.

Language: Английский

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Photoinduced Regiodivergent and Enantioselective Cross-Coupling of Glycine Derivatives with Hydrocarbon Feedstocks

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 2, 2025

Regiodivergent asymmetric synthesis represents a transformative strategy for the efficient generation of structurally diverse chiral products from single set starting materials, significantly enriching their enantiomeric composition. However, design radical-mediated regiodivergent and enantioselective reactions that can accommodate wide range functional groups substrates has posed significant challenges. The obstacles primarily lie in switching regioselectivity achieving high enantiodiscrimination, especially when dealing with high-energy intermediates. To address these issues, we have developed new catalytic system integrates photoinduced hydrogen atom transfer (HAT) copper catalysis, involving fine-tuning ligands, additives, other reaction parameters. facilitates cross-couplings between N-aryl glycine ester/amide derivatives abundant hydrocarbon feedstocks through strong C(sp3)–H bond activation. This approach allows controlled stereoselective formation C(sp3)–C(sp3) C(sp3)–N bonds, yielding rich variety C- or N-alkylated esters amides commendable yields (up to 92% yield), exclusive regioselectivities (typically >20:1 rr), enantioselectivities 96% ee). Our methodology not only provides promising avenue incorporation alkyl functionalities onto specific sites biologically molecules but also offers practical while simultaneously induction within photochemical reactions.

Language: Английский

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Rhodium‐Catalyzed C−H Activation‐Based Construction of Axially and Centrally Chiral Indenes through Two Discrete Insertions

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(30), P. 16628 - 16633

Published: May 19, 2021

Abstract Reported herein is asymmetric [3+2] annulation of arylnitrones with different classes alkynes catalyzed by chiral rhodium(III) complexes, the nitrone acting as an electrophilic directing group. Three indenes/indenones have been effectively constructed, depending on nature substrates. The coupling system features mild reaction conditions, excellent enantioselectivity, and high atom‐economy. In particular, N ‐benzylnitrones sterically hindered afforded C−C or C−N atropochiral pentatomic biaryls a C‐centered point‐chirality in enantio‐ diastereoselectivity (45 examples, average 95.6 % ee ). These center axis are disposed distal fashion they constructed via two distinct migratory insertions that stereo‐determining under catalyst control.

Language: Английский

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Thioether-Directed NiH-Catalyzed Remote γ-C(sp³)–H Hydroamidation of Alkenes by 1,4,2-Dioxazol-5-ones

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(37), P. 14962 - 14968

Published: Sept. 8, 2021

A NiH-catalyzed thioether-directed cyclometalation strategy is developed to enable remote methylene C–H bond amidation of unactivated alkenes. Due the preference for five-membered nickelacycle formation, chain-walking isomerization initiated by NiH insertion an alkene can be terminated at γ-methylene site from moiety. By employing 2,9-dibutyl-1,10-phenanthroline (L4) as ligand and dioxazolones reagent, occurs γ-C(sp3)–H bonds afford amide products in up 90% yield (>40 examples) with remarkable regioselectivity (up 24:1 rr).

Language: Английский

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Merging NiH Catalysis and Inner-Sphere Metal-Nitrenoid Transfer for Hydroamidation of Alkynes

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(15), P. 5867 - 5877

Published: April 9, 2021

The formal hydroamination/hydroamidation utilizing metal hydride is an appealing synthetic tool for the construction of valuable nitrogen-containing compounds from unsaturated hydrocarbons. While significant advances have been made functionalizations alkenes in this realm, direct hydroamidation alkynes remains rather limited due to high feasibility key metal-alkenyl intermediate choose other reaction pathways. Herein, we report a NiH-catalyzed strategy with dioxazolones, which allows convenient access synthetically useful secondary enamides (E)-anti-Markovnikov or Markovnikov selectivity. viable both terminal and internal also tolerant range subtle functional groups. With H2O found as essential component catalyst turnovers, involvement inner-sphere nitrenoid transfer proposed that outcompetes undesired semireduction process, thus representing first example show competence Ni catalysis metal-nitrenoid formation dioxazolones.

Language: Английский

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