Cooperative Photoredox and N‐Heterocyclic Carbene Catalyzed Fluoroaroylation for the Synthesis of α‐Trifluoromethyl‐Substituted Ketones DOI Open Access
Xiaoye Yu,

Anirban Maity,

Armido Studer

et al.

Angewandte Chemie, Journal Year: 2023, Volume and Issue: 135(48)

Published: Oct. 9, 2023

Abstract α‐Trifluoromethylated ketones have attracted significant attention as valuable building blocks in organic synthesis. Such compounds are generally accessed through trifluoromethylation of ketones. Here we report an alternative disconnection approach for the construction α‐CF 3 carbonyl by using aroyl fluorides bifunctional reagents fluoroaroylation gem ‐difluoroalkenes cooperative photoredox and N‐heterocyclic carbene (NHC) catalysis. This strategy bypasses use expensive or sensitive and/or requirement ketone pre‐functionalization, thus enabling efficient general synthetic method to access ‐substituted A wide variety bearing a diverse set functional groups eligible substrates. Notably, developed methodology also provides rapid mono‐ difluoroalkyl Mechanistic studies reveal that merging catalysis with NHC is essential reaction.

Language: Английский

Cooperative Photoredox and N‐Heterocyclic Carbene Catalyzed Fluoroaroylation for the Synthesis of α‐Trifluoromethyl‐Substituted Ketones DOI
Xiaoye Yu,

A.C. Maity,

Armido Studer

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(48)

Published: Oct. 9, 2023

α-Trifluoromethylated ketones have attracted significant attention as valuable building blocks in organic synthesis. Such compounds are generally accessed through trifluoromethylation of ketones. Here we report an alternative disconnection approach for the construction α-CF3 carbonyl by using aroyl fluorides bifunctional reagents fluoroaroylation gem-difluoroalkenes cooperative photoredox and N-heterocyclic carbene (NHC) catalysis. This strategy bypasses use expensive or sensitive and/or requirement ketone pre-functionalization, thus enabling efficient general synthetic method to access -substituted A wide variety bearing a diverse set functional groups eligible substrates. Notably, developed methodology also provides rapid mono- difluoroalkyl Mechanistic studies reveal that merging catalysis with NHC is essential reaction.

Language: Английский

Citations

33
BF3-Catalyzed Intramolecular Fluorocarbamoylation of Alkynes via Halide Recycling DOI
E. Ali McKnight, Ramon Arora, Ekadashi Pradhan

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(20), P. 11012 - 11018

Published: May 12, 2023

A BF3-catalyzed atom-economical fluorocarbamoylation reaction of alkyne-tethered carbamoyl fluorides is reported. The catalyst acts as both a fluoride source and Lewis acid activator, thereby enabling the formal insertion alkynes into strong C-F bonds through halide recycling mechanism. developed method provides access to 3-(fluoromethylene) oxindoles γ-lactams with excellent stereoselectivity, including fluorinated derivatives known protein kinase inhibitors. Experimental computational studies support stepwise mechanism for involving turnover-limiting cyclization step, followed by internal transfer from BF3-coordinated adduct. For methylene oxindoles, thermodynamically driven Z-E isomerization facilitated transition state aromatic character. In contrast, this stabilization not relevant γ-lactams, which results in higher barrier exclusive formation Z-isomer.

Language: Английский

Citations

31
Observation of unusual outer-sphere mechanism using simple alkenes as nucleophiles in allylation chemistry DOI Creative Commons
Yaxin Zeng, Han Gao, Zhong‐Tao Jiang

et al.

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

Published: May 21, 2024

Abstract Transition-metal catalyzed allylic substitution reactions of alkenes are among the most efficient methods for synthesizing diene compounds, driven by inherent preference an inner-sphere mechanism. Here, we present a demonstration outer-sphere mechanism in Rh-catalyzed reaction simple using gem -difluorinated cyclopropanes as allyl surrogates. This unconventional offers opportunity fluorine recycling via C − F bond cleavage/reformation, ultimately delivering carbofluorination products. The developed method tolerates wide range alkenes, providing access to secondary, tertiary fluorides and -difluorides with 100% atom economy. DFT calculations reveal that formation goes through unusual nucleophilic allyl-Rh species instead migration insertion, generated carbon cation then forms tetrafluoroborate fluoride shuttle.

Language: Английский

Citations

12
Silicate-Confined Hydrogen on Nanoscale Zerovalent Iron for Efficient Defluorination Reactions DOI

Minzi Liao,

Shengxi Zhao,

Guangming Zhan

et al.

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

Published: Jan. 15, 2025

Defluorination reactions are increasingly vital due to the extensive use of organofluorine compounds with robust carbon–fluorine (C–F) bonds; particularly, efficient defluorination widespread and persistent per- polyfluoroalkyl substances under mild conditions is crucial their accumulation in environment human body. Herein, we demonstrate that surface-modified silicate pronounced proton affinity can confine active hydrogen (•H) onto nanoscale zerovalent iron (nZVI) by withdrawing electrons from nZVI react bound protons, generating confined (•H*) for ambient conditions. The exposed silicon cation (Siσ+) functions as a Lewis acid site activate C–F bond forming Siσ+...F––C substantially lowers energy barrier nucleophilic •H* attack, thereby facilitating selective hydrodefluorination subsequent fluorine immobilization. In column flow reactor, silicate-modified efficiently removes perfluorooctanoic (PFOA) concentrations ranging 0.24 24 μmol/L 75–92% efficiencies, 8 times higher than those nZVI, environmentally friendly alkyl carboxylic acids primary products. Besides PFOA, this novel also realizes deep other compounds, including perfluorooctanesulfonates fluoroquinolones, demonstrating its superior potential.

Language: Английский

Citations

2
C−F Bond Insertion: An Emerging Strategy for Constructing Fluorinated Molecules DOI Creative Commons
Arushi Garg, Alex Haswell, Matthew N. Hopkinson

et al.

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: 30(20)

Published: Jan. 25, 2024

C-F Insertion reactions, where an organic fragment formally inserts into a carbon-fluorine bond in substrate, are highly attractive, yet largely unexplored, methods to prepare valuable fluorinated molecules. The inherent strength of bonds and the resulting need for large thermodynamic driving force initiate cleavage often leads sequestering released fluoride unreactive by-product. Recently, however, several groups have succeeded overcoming this challenge, opening up study insertion as efficient atom-economical approach compounds. In article, recent breakthroughs discussed focusing on key conceptual advances that allowed both subsequent incorporation product.

Language: Английский

Citations

6
Double strain-release enables formal C–O/C–F and C–N/C–F ring-opening metathesis DOI Creative Commons

Yulei Zhu,

Jie Jia,

Xiangyu Song

et al.

Chemical Science, Journal Year: 2024, Volume and Issue: 15(34), P. 13800 - 13806

Published: Jan. 1, 2024

Metathesis reactions have been established as a powerful tool in organic synthesis. While great advances were achieved double-bond metathesis, like olefin metathesis and carbonyl single-bond has received less attention the past decade. Herein, we describe first C(sp

Language: Английский

Citations

6
Intramolecular Fluoroacylation Enabled by TrBF4-Catalyzed Fluoride Recycling DOI

Alice A. Mcknight,

Yuriko H. Fujisato,

Namrata Khanal

et al.

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 27, 2025

Alkyne- and alkene-tethered acyl fluorides undergo intramolecular carbofluorination via fluoride recycling using catalytic TrBF4. Excellent stereoselectivity is observed for the alkyne addition, enabling access to novel fluorinated indan-2-ones (all ≥95:5 E/Z) cyclopentan-2-ones (85:15 E/Z). Fluorinated chroman-2-ones tertiary alkyl can also be synthesized this method, comparing favorably previously reported protocols that employ expensive metal catalysts under harsher conditions.

Language: Английский

Citations

0
Non-Classical Molecular Activation by Phosphines and N-Heterocyclic Carbenes and Its Application to Catalytic Reactions DOI
Hayato Fujimoto, Kosuke Yasui, Mamoru Tobisu

et al.

Bulletin of the Chemical Society of Japan, Journal Year: 2023, Volume and Issue: 96(9), P. 872 - 886

Published: July 27, 2023

Abstract This Award Account reports our recent studies concerning the catalytic transformations that involve a non-classical mode of molecular activation by tertiary phosphines and N-heterocyclic carbenes (NHCs). Regarding organophosphine catalysis, we successfully designed reactions based on P(III)/P(V) redox couple. A protocol for generating pentacoordinate P(V) species was devised reaction phosphines, acyl fluorides alkynoates. The ability thus generated fluorophosphoranes to participate in ligand coupling metathesis with organosilicon nucleophiles enables synthetic are otherwise unattainable, including intermolecular carbofluorination alkynes hydroalkenylation enol ethers. nucleophilic NHC use imidazolium-based NHCs can generate deoxy-Breslow intermediates sufficiently promote aromatic substitution aryl halides, ethers anilides. also be used styrene derivatives, allowing generation series ylide serve as non-stabilized vinyl anion equivalents. These results demonstrate involving carbanions conducted under conditions without strong organometallic nucleophiles.

Language: Английский

Citations

6
Carbofluorination of Alkenes with gem-Difluorinated Cyclopropanes as Bifunctional Reagents Enabled by Well-Define Rhodium Catalysts DOI Creative Commons
Yaxin Zeng, Zhong‐Tao Jiang,

Yulei Zhu

et al.

Published: Aug. 21, 2023

Herein, we report a Rh-catalyzed carbofluorination of alkenes using gem-difluorinated cyclopropanes as bifunctional reagents. The developed method tolerates wide range alkenes, providing access to secondary, tertiary fluorides and gem-difluorides with 100% atom-economy under mild conditions. resulting can be further transformed yield C−C, C−N, C−O bifunctionalization products. Cationic dicarbonyl rhodium tetrafluoroborate has been identified the only highly efficient catalyst in this reaction. Preliminary mechanistic studies reveal that addition fluorine atom is mediated by ion, which acts anion shuttle.

Language: Английский

Citations

6
Efficient Amide Formation from Non‐Activated Cyclopropyl Ester via Acyl Fluoride Generation Using Hypervalent Iodine(III) Reagent and Selectfluor DOI Open Access
Eunsol Choi,

Hee‐Chan Jeong,

Ye‐Lin Han

et al.

Asian Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 12(9)

Published: July 27, 2023

Abstract A novel and unique activation method for esters possessing a non‐activated cyclopropyl moiety as potential activating group is developed acyl fluoride generation using hypervalent iodine(III) reagent Selectfluor. The resulting fluoride, which versatile synthetic intermediate, was smoothly transformed into the various carbonyl compounds, in particular, amides. This protocol can be applied to chemoselective of diester compounds.

Language: Английский

Citations

4