Asymmetric Catalytic Rearrangements with α-Diazocarbonyl Compounds

Accounts of Chemical Research, Journal Year: 2022, Volume and Issue: 55(3), P. 415 - 428

Published: Jan. 14, 2022

Conspectusα-Diazocarbonyl compounds serve as nucleophiles, dipoles, carbene precursors, and rare electrophiles, enabling a vast array of organic transformations under the influence metal catalysts. Among them, rearrangement processes are attractive provide straightforward efficient accesses to one-carbon extension adducts or heteroatom-containing molecules. The reactions occur upon release dinitrogen after nucleophilic addition before ylide formation. Although significant progress has been made for these two types reactions, issue enantiocontrol is challenging because final optically enriched products generated via multistep inherent spacial arrangement intermediates more less on regio- enantioselectivity.In this Account, we collected several rearrangements α-diazocarbonyl compounds, showcasing catalysts tailored strategies tackling enantioselective varieties reactions. Our research group initiated catalytic asymmetric during development chiral Feng N,N′-dioxide–metal complex others. As kind useful Lewis acid catalyst complexes favorable activation various carbonyl accelerating diastereo- α-diazoesters sequential in either an intermolecular intramolecular manner. Aldehydes, acyclic cyclic ketone derivatives, α,β-unsaturated ketones could participate homologation obvious ligand-acceleration effect observed processes. For example, Roskamp–Feng reaction aldehydes gives active β-ketoesters through H-shift, overwhelming aryl shift oxygen attack. preference derivatives be excellent control An unusual electrophilic α-amination aryl/alkyl even complicated homologation/dyotropic rearrangement/interconversion/[3 + 2] cycloaddition cascade used construct dimeric polycyclic were discovered result selection ligands additives. On basis understanding interaction functional with catalysis key enantio-determining issues ylide-based rearrangements, designed new by introducing pyrazole-1-carboxyl acceptor unit, which benefit formation both carbenoid species catalyst-bound ylides deliver stereoselectivity. Taking advantage Ni(II) Co(II) N,N′-dioxide ligands, realized kinds [2,3]-sigmatropic such Doyle–Kirmse allylic sulfides selenides, [2,3]-Stevens vinyl-substituted α-diazo pyrazoleamides thioacetates, Sommelet–Hauser aryl-substituted thioamides, thio-Claisen 2-thio-indoles well. Moreover, strategy was shown applicable highly γ-selective insertion into N–H bonds secondary amines pyrazoleamides.

Language: Английский

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Cobalt‐Catalyzed Enantioselective Hydroamination of Arylalkenes with Secondary Amines

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 62(2)

Published: Nov. 7, 2022

Abstract Catalytic asymmetric hydroamination of alkenes with Lewis basic amines is great interest but remains a challenge in synthetic chemistry. Here, we developed Co‐catalyzed arylalkenes directly using commercially accessible secondary amines. This process enables the efficient access to valuable α ‐chiral tertiary good excellent yields and enantioselectivities. Mechanistic studies suggest that reaction includes CoH‐mediated hydrogen atom transfer (MHAT) arylalkenes, followed by pivotal catalyst controlled S N 2‐like pathway between situ generated electrophilic cationic alkylcobalt(IV) species free radical‐polar crossover strategy not only provides straightforward alternative approach for synthesis enantioenriched ‐tertiary amines, also underpins substantial opportunities developing radical functionalization various nucleophiles oxidative MHAT catalysis.

Language: Английский

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Feng chiralN,N′-dioxide ligands: uniqueness and impacts

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(14), P. 3676 - 3683

Published: Jan. 1, 2023

Privileged Feng ligands feature designer N , ’-dioxide amides with a unique conformational and coordination flexibility. This highlight summarizes the increasingly profound impact of on modern catalytic asymmetric synthesis.

Language: Английский

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A Spiro Phosphamide Catalyzed Enantioselective Proton Transfer of Ylides in a Free Carbene Insertion into N−H Bonds

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(15)

Published: Feb. 14, 2023

Free carbene readily causes multiple side reactions due to its high energy, thus asymmetric transformation is very difficult. We present here our findings of high-pKa Brønsted acid catalysts that enable free insertion into N-H bonds amines prepare chiral α-amino derivatives with enantioselectivity. Under irradiation visible light, diazo compounds produce high-energy carbenes are captured by form ylide intermediates, and then the newly designed acids, spiro phosphamides, promote proton transfer ylides afford products. Computational kinetic studies uncover principle for rational design proton-transfer explain how accelerate this provide stereocontrol.

Language: Английский

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Asymmetric Epoxidation of Alkenes Catalyzed by a Cobalt Complex

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(28), P. 15611 - 15618

Published: July 5, 2023

Asymmetric epoxidation of alkenes catalyzed by nonheme chiral Mn–O and Fe–O catalysts has been well established, but Co–O for the purpose remain virtually undeveloped due to oxo wall. Herein is first reported a cobalt complex realize enantioselective cyclic acyclic trisubstituted using PhIO as oxidant in acetone, wherein tetra-oxygen-based N,N′-dioxide with sterically hindered amide subunits plays crucial role supporting formation intermediate electrophilic oxygen transfer. Mechanistic studies, including HRMS measurements, UV–vis absorption spectroscopy, magnetic susceptibility, DFT calculations, were carried out, confirming species quartet Co(III)-oxyl tautomer. The mechanism origin enantioselectivity also elucidated based on control experiments, nonlinear effects, kinetic calculations.

Language: Английский

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Iron-Catalyzed Asymmetric Imidation of Sulfides via Sterically Biased Nitrene Transfer

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(26), P. 18050 - 18060

Published: June 15, 2024

Transition-metal-catalyzed enantioselective nitrene transfer to sulfides has emerged as one of the most powerful strategies for rapid construction enantioenriched sulfimides. However, achieving stereocontrol over highly active earth-abundant transition-metal nitrenoid intermediates remains a formidable challenge compared with precious metals. Herein, we disclose chiral iron(II)/N,N′-dioxide-catalyzed imidation dialkyl and alkyl aryl using iminoiodinanes precursors. A series sulfimides were obtained in moderate-to-good yields high enantioselectivities (56 examples, up 99% yield, 98:2 e.r.). The utility this methodology was demonstrated by late-stage modification complex molecules synthesis insecticide sulfoxaflor related bioactive compounds. Based on experimental studies theoretical calculations, water-bonded high-spin iron species identified key intermediate. observed stereoselectivity original from steric repulsion between amide unit ligand cave bulky substituent sulfides. Additionally, dioxazolones proved be suitable acylnitrene precursors presence an iron(III)/N,N′-dioxide complex, resulting formation enantioselectivity-reversed (14 81% 97:3

Language: Английский

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A visible-light-promoted metal-free approach for N–H insertions by using donor/donor diazo precursors

Green Chemistry, Journal Year: 2024, Volume and Issue: 26(8), P. 4600 - 4608

Published: Jan. 1, 2024

A metal-free and catalyst-free strategy is reported to achieve N–H insertions by coupling N -tosylhydrazones with diverse amines including aminopyridines, anilines, aliphatic amines, other nucleophiles such as imidazoles indoles.

Language: Английский

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Advancing Heterogeneous Organic Synthesis With Coordination Chemistry‐Empowered Single‐Atom Catalysts

Advanced Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 18, 2024

Abstract For traditional metal complexes, intricate chemistry is required to acquire appropriate ligands for controlling the electron and steric hindrance of active centers. Comparatively, preparation single‐atom catalysts much easier with more straightforward effective accesses arrangement control The presence coordination atoms or neighboring functional on supports' surface ensures stability single‐atoms their interactions individual substantially regulate performance Therefore, collaborative interaction between surrounding environment enhances initiation reaction substrates formation transformation crucial intermediate compounds, which imparts significant catalytic efficacy, rendering them a valuable framework investigating correlation structure activity, as well mechanism in organic reactions. Herein, comprehensive overviews both homogeneous complexes reactions are provided. Additionally, reflective conjectures about advancement synthesis also proposed present reference later development.

Language: Английский

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Enantioselective Photochemical Carbene Insertion into C–C and C–H Bonds of 1,3-Diketones by a Guanidine-Amide Organocatalyst

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(7), P. 4656 - 4666

Published: March 22, 2023

A visible-light-induced enantioselective free carbene transfer reaction of α-diazoesters with 1,3-diketones is established by utilizing a chiral bifunctional guanidine-amide organocatalyst. Selective insertion into the C–C or C–H bonds 1,3-diketone could be achieved bearing different steric hindrances. The transformations enable preparation series 1,4-diketones quaternary carbon center 2-substituted-1,3-diketones in good enantioselectivities. On basis control experiments and DFT calculation, stepwise triplet coupling pathway suggested. possible mechanism proposed to explain origin high enantioselectivities via hydrogen-bonds electrostatic interactions catalyst.

Language: Английский

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Enantioselective synthesis of chiral amides by carbene insertion into amide N–H bond

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: June 5, 2024

Chiral amides are important structure in many natural products and pharmaceuticals, yet their efficient synthesis from simple amide feedstock remains challenge due to its weak Lewis basicity. Herein, we describe our study of the enantioselective chiral by N-alkylation primary taking advantage an achiral rhodium squaramide co-catalyzed carbene N-H insertion reaction. This method features mild condition, rapid reaction rate (in all cases 1 min) a wide substrate scope with high yield excellent enantioselectivity. Further product transformations show synthetic potential this Mechanistic studies reveal that non-covalent interactions between catalyst intermediate play critical role enantiocontrol.

Language: Английский

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