Catalytic, asymmetric carbon–nitrogen bond formation using metal nitrenoids: from metal–ligand complexes <i>via</i> metalloporphyrins to enzymes

Fanourakis, Alexander; Phipps, Robert J.

doi:10.1039/d3sc04661c

Cited by 12 publications

(3 citation statements)

References 260 publications

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“…Further stereospecific oxidation of chiral sulfimides enables access to enantioenriched sulfoximines, which have garnered increasing recognition in medicinal chemistry and agricultural science. , Among various methods documented in the literatures, ,, transition-metal-catalyzed enantioselective nitrenoid transfer to sulfides is a highly efficient strategy for rapid construction of sulfimides in the enantioenriched form (Scheme b). Inspired by the original studies of Kwart and Khan, metal nitrenoids have been employed as versatile intermediates in numerous nitrene transfer reactions encompassing insertion into heteroatom lone pairs, addition to alkenes, insertion into C–H bonds, and so on. − Remarkable progress has been achieved in the realm of the asymmetric imidation of sulfides. Uemura and Taylor reported early examples with chiral copper(I)/bis(oxazoline) , as the catalyst, affording moderate enantioselectivities.…”

Section: Introductionmentioning

confidence: 99%

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

Liu,

Wu,

Zhang

et al. 2024

J. Am. Chem. Soc.

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

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Section: Introductionmentioning

confidence: 99%

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

Liu,

Wu,

Zhang

et al. 2024

J. Am. Chem. Soc.

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“…Free nitrenes themselves, however, are typically too reactive to allow controlled, selective intermolecular processes. In contrast, catalytic approaches that proceed via metal nitrenoids have proven incredibly versatile in permitting a broad range of C–H amination and alkene aziridination processes through insertion into C–H bonds and addition to alkenes, respectively . A number of metals are proficient at forming metal nitrenoids, and among these, rhodium (II,II) paddlewheel complexes have proven very effective, and Rh-catalyzed amination and aziridination have become mainstream synthetic methods, aided by the popularization of Du Bois’ Rh 2 (esp) 2 as an active and functional group tolerant catalyst .…”

Section: Introductionmentioning

confidence: 99%

“…A number of metals are proficient at forming metal nitrenoids, and among these, rhodium (II,II) paddlewheel complexes have proven very effective, and Rh-catalyzed amination and aziridination have become mainstream synthetic methods, aided by the popularization of Du Bois’ Rh 2 (esp) 2 as an active and functional group tolerant catalyst . A continuing challenge in the field is that of developing generally applicable ligand strategies for asymmetric nitrene transfer . An established approach for rhodium paddlewheels involves the replacement of the achiral carboxylate ligands with chiral variants, as demonstrated in early work on amination of benzylic C–H bonds from Hashimoto et al, Müller et al, Davies and Reddy, and Du Bois and Zalatan and followed by recent important intermolecular contributions from Dauban et al (Figure a, left) .…”

Section: Introductionmentioning

confidence: 99%

Enantioselective Nitrene Transfer to Hydrocinnamyl Alcohols and Allylic Alcohols Enabled by Systematic Exploration of the Structure of Ion-Paired Rhodium Catalysts

Hodson,

Takano,

Fanourakis

et al. 2024

J. Am. Chem. Soc.

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This work describes highly enantioselective nitrene transfer to hydrocinnamyl alcohols (benzylic C−H amination) and allylic alcohols (aziridination) using ion-paired Rh (II,II) complexes based on anionic variants of Du Bois' esp ligand that are associated with cinchona alkaloid-derived chiral cations. Directed by a substrate hydroxyl group, our previous work with these complexes had not been able to achieve high enantioselectivity on these most useful short-chain compounds, and we overcame this challenge through a combination of catalyst design and modified conditions. A hypothesis that modulation of the linker between the anionic sulfonate group and the central arene spacer might provide a better fit for shorter chain length substrates led to the development of a new biaryl-containing scaffold, which has allowed a broad scope for both substrate classes to be realized for the first time. Furthermore, we describe a systematic structural "knockout" study on the cinchona alkaloid-derived chiral cation to elucidate which features are crucial for high enantioinduction. De novo synthesis of modified scaffolds led to the surprising finding that for high ee the quinoline nitrogen of the alkaloid is crucial, although its location within the heterocycle could be varied, even leading to a superior catalyst. The free hydroxyl is also crucial and should possess the naturally occurring diastereomeric configuration of the alkaloid. These findings underline the privileged nature of the cinchona alkaloid scaffold and provide insight into how these cations might be used in other catalysis contexts.

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Iron Corrole‐Catalyzed Intramolecular Amination Reactions of Alkyl Azides. Spectroscopic Characterization and Reactivity of [Fe^V(Cor)(NAd)]

You,

Shing,

et al. 2024

Advanced Science

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As nitrogen analogues of iron‐oxo species, high‐valent iron‐imido species have attracted great interest in the past decades. FeV‐alkylimido species are generally considered to be key reaction intermediates in Fe(III)‐catalyzed C(sp3)─H bond aminations of alkyl azides but remain underexplored. Here, it is reported that iron‐corrole (Cor) complexes can catalyze a wide range of intramolecular C─H amination reactions of alkyl azides to afford a variety of 5‐, 6‐ and 7‐membered N‐heterocycles, including alkaloids and natural product derivatives, with up to 3880 turnover numbers (TONs) and excellent diastereoselectivity (>99:1 d.r.). Mechanistic studies including density functional theory (DFT) calculations and intermolecular hydrogen atom abstraction (HAA) reactions reveal key reactive FeV‐alkylimido intermediates. The [FeV(Cor)(NAd)] (Ad = adamantyl) complex is independently prepared and characterized through electron paramagnetic resonance (EPR), resonance Raman (rR) measurement, and X‐ray photoelectron spectroscopy (XPS). This complex is reactive toward HAA reactions with kinetic isotope effects (KIEs) similar to [Fe(Cor)]‐catalyzed intramolecular C─H amination of alkyl azides.

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Catalytic, asymmetric carbon–nitrogen bond formation using metal nitrenoids: from metal–ligand complexes via metalloporphyrins to enzymes

Abstract: This review discusses the varied catalyst design strategies that have been applied to asymmetric C−N bond formation using metal nitrenoids. The outstanding challenges are also identified with the aim of encouraging further investigation in the field.

Cited by 12 publications

References 260 publications

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

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

Enantioselective Nitrene Transfer to Hydrocinnamyl Alcohols and Allylic Alcohols Enabled by Systematic Exploration of the Structure of Ion-Paired Rhodium Catalysts

Iron Corrole‐Catalyzed Intramolecular Amination Reactions of Alkyl Azides. Spectroscopic Characterization and Reactivity of [Fe^V(Cor)(NAd)]

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Catalytic, asymmetric carbon–nitrogen bond formation using metal nitrenoids: from metal–ligand complexes via metalloporphyrins to enzymes

Abstract: This review discusses the varied catalyst design strategies that have been applied to asymmetric C−N bond formation using metal nitrenoids. The outstanding challenges are also identified with the aim of encouraging further investigation in the field.

Cited by 12 publications

References 260 publications

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

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

Enantioselective Nitrene Transfer to Hydrocinnamyl Alcohols and Allylic Alcohols Enabled by Systematic Exploration of the Structure of Ion-Paired Rhodium Catalysts

Iron Corrole‐Catalyzed Intramolecular Amination Reactions of Alkyl Azides. Spectroscopic Characterization and Reactivity of [FeV(Cor)(NAd)]

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Iron Corrole‐Catalyzed Intramolecular Amination Reactions of Alkyl Azides. Spectroscopic Characterization and Reactivity of [Fe^V(Cor)(NAd)]