Synthesis of a stable crystalline nitrene

Science, Journal Year: 2024, Volume and Issue: 385(6706), P. 318 - 321

Published: June 13, 2024

Nitrenes are a highly reactive, yet fundamental, compound class. They possess monovalent nitrogen atom and usually short life span, typically in the nanosecond range. Here, we report on synthesis of stable nitrene by photolysis arylazide M

Language: Английский

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P–P Coupling with and without Terminal Metal–Phosphorus Intermediates

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

Published: Jan. 28, 2025

Terminal metal–phosphorus (M–P) complexes are of significant contemporary interest as potential platforms for P-atom transfer (PAT) chemistry. Decarbonylation metal–phosphaethynolate (M–PCO) has emerged a general synthetic approach to terminal M–P complexes. that stabilized by strong multiple bonds kinetically persistent and isolable. In the absence stabilization, formation diphosphorus-bridged (i.e., M–P–P–M species) is often interpreted evidence intermediacy reactive, unobserved species. Here, we demonstrate while diphosphorus can arise from reactive species, P–P coupling also proceed directly M–PCO species without Photochemical decarbonylations pincer-supported Ni (II)–PCO complex at 77 K afford spectroscopically observed Ni–P complex, which best described triplet, Ni(II)-metallophosphinidene with two unpaired electrons localized on atomic phosphorus ligand. Thermal annealing this transient results in rapid dimerization corresponding P22–-bridged dinickel complex. Unexpectedly, same be accessed via thermally promoted process light. The analysis reaction kinetics, isotope-labeling studies, computational indicate thermal proceeds noncanonical mechanism avoids intermediates. Together, these represent first observation characterized intermediates not required obtain products. These observations provide critical mechanistic understanding activation modes relevant transfer.

Language: Английский

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

Chemical Science, Journal Year: 2023, Volume and Issue: 14(44), P. 12447 - 12476

Published: Jan. 1, 2023

The introduction of nitrogen atoms into small molecules is fundamental importance and it vital that ever more efficient selective methods for achieving this are developed. With aim, the potential nitrene chemistry has long been appreciated but its application constrained by extreme reactivity these labile species. This liability however can be attenuated complexation with a transition metal resulting nitrenoids have unique highly versatile which includes amination certain types aliphatic C-H bonds as well reactions alkenes to afford aziridines. At least one new chiral centre typically formed in processes development catalysts exert control over enantioselectivity nitrenoid-mediated become growing area research, particularly past two decades. Compared some synthetic methods, nitrenoid notable chemists draw from diverse array metals , ranging metal-ligand complexes, bearing variety ligand types, via bio-inspired metalloporphyrins, all way through to, very recently, engineered enzymes themselves. In latter category particular, rapid progress being made, rate suggests approach may instrumental addressing outstanding challenges field. review covers key developments strategies shaped field, addition latest advances, up until September 2023.

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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Chiral Cp^xRhodium(III)‐Catalyzed Enantioselective Aziridination of Unactivated Terminal Alkenes

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(12)

Published: Jan. 27, 2024

Chiral cyclopentadienyl-rhodium(III) Cp

Language: Английский

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Decarboxylative stereoretentive C–N coupling by harnessing aminating reagent

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

Published: May 6, 2024

Abstract In recent decades, strategies involving transition-metal catalyzed carbon-carbon or carbon-heteroatom bond coupling have emerged as potent synthetic tools for constructing intricate molecular architectures. Among these, decarboxylative carbon-nitrogen formation using abundant carboxylic acids their derivatives has garnered notable attention accessing alkyl- arylamines, one of key pharmacophores. While several amination methods been developed, the involvement a common carboradical intermediate currently poses challenges in achieving stereospecific transformation toward chiral alkylamines. Herein, we present base-mediated, stereoretentive amidation by harnessing 1,4,2-dioxazol-5-one reactive and robust amidating reagent under transition-metal-free ambient conditions, encompassing all types primary, secondary tertiary acids, thereby providing access to important pharmacophore, α-chiral amines. This method exhibits high functional group tolerance, convenient scalability, ease applicability 15 N-isotope labeling, thus accentuating its utilities. Experimental computational mechanistic investigations reveal sequence elementary steps: i) nucleophilic addition carboxylate dioxazolone, ii) rearrangement form dicarbonyl N-hydroxy intermediate, iii) conversion hydroxamate, followed Lossen-type rearrangement, finally, iv) reaction situ generated isocyanate with leading C–N manner.

Language: Английский

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Isolation and characterization of a triplet nitrene

Nature Chemistry, Journal Year: 2024, Volume and Issue: 17(1), P. 38 - 43

Published: Nov. 19, 2024

Language: Английский

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Electrochemical Enantioselective C–H Annulation by Achiral Rhodium(III)/Chiral Brønsted Base Domino Catalysis

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(11), P. 8160 - 8167

Published: May 10, 2024

Rhodium(III)-catalyzed enantioselective C–H activation has emerged as a powerful tool for assembling enabling chiral molecules. However, this approach is significantly hampered by the cumbersome synthetic routes preparing rhodium catalysts. In sharp contrast, we herein report on an electrochemical domino catalysis system that exploits achiral Cp*-rhodium catalyst along with easily accessible Brønsted base activation/annulation reaction of alkenes benzoic acids. Our strategy offers environmentally benign and most user-friendly synthetically useful phthalides in good enantioselectivity, employing electricity sustainable oxidant.

Language: Английский

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Triplet carbenes with transition-metal substituents

Nature Chemistry, Journal Year: 2024, Volume and Issue: 16(11), P. 1788 - 1793

Published: Aug. 5, 2024

Language: Английский

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Visible-Light-Promoted Enantioselective α-Amidation of Aldehydes by Harnessing Organo-Iron Dual Catalysis

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(32), P. 22172 - 22179

Published: July 30, 2024

The strategic integration of organocatalysis with transition-metal catalysis to achieve otherwise unattainable stereoselective transformations may serve as a powerful synthetic tool. Herein, we present synthetically versatile α-amidation aldehydes by leveraging dual iron and chiral enamine in an enantioselective manner (up >99:1 er). Experimental computational studies have led us propose new mechanistic platform, wherein visible-light-promoted LMCT generates [Fe(II)Cl

Language: Английский

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