Difluorocarbene
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Difluoromethylation of (hetero)aryl chlorides with chlorodifluoromethane catalyzed by nickel Open
Relatively low reactivity hinders using chlorodifluoromethane (ClCF 2 H) for general difluoromethylation with organic molecules, despite its availability as an inexpensive industrial chemical. To date, transformations of ClCF 2 H are very …
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China's flourishing synthetic organofluorine chemistry: innovations in the new millennium Open
The new millennium has witnessed the rapid development of synthetic organofluorine chemistry all over the world, and chemists in China have made significant contributions in this field. This review aims to provide a brief introduction to C…
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Deconstructive Functionalizations of Unstrained Carbon–Nitrogen Cleavage Enabled by Difluorocarbene Open
Transition-metal- or oxidant-promoted deconstructive functionalizations of noncyclic carbon-nitrogen bonds are well established, usually only leaving one moiety functionalized toward the final product. In contrast, concomitant C- and N-fun…
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An Unconventional Mechanistic Insight into SCF<sub>3</sub> Formation from Difluorocarbene: Preparation of <sup>18</sup>F‐Labeled α‐SCF<sub>3</sub> Carbonyl Compounds Open
Trifluoromethylthiolation by sulfuration of difluorocarbene with elemental sulfur is described for the first time, which overrides long‐standing trifluoromethyl anion‐based theory. Mechanistic elucidation reveals an unprecedented chemical …
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Difluorocarbene Generation from TMSCF<sub>3</sub>: Kinetics and Mechanism of NaI-Mediated and Si-Induced Anionic Chain Reactions Open
The mechanism of CF2 transfer from TMSCF3 (1), mediated by TBAT (2-12 mol %) or by NaI (5-20 mol %), has been investigated by in situ/stopped-flow 19F NMR spectroscopic analysis of the kinetics of alkene difluorocyclopropanation and compet…
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Palladium Difluorocarbene Involved Catalytic Coupling with Terminal Alkynes Open
Open AccessCCS ChemistryRESEARCH ARTICLE1 Oct 2020Palladium Difluorocarbene Involved Catalytic Coupling with Terminal Alkynes Xue-Ying Zhang, Xia-Ping Fu, Shu Zhang and Xingang Zhang Xue-Ying Zhang Key Laboratory of Organofluorine Chemistr…
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Difluorocarbene transfer from a cobalt complex to an electron-deficient alkene Open
A Co(ii) porphyrin complex catalyses difluorocarbene transfer to an acrylate using TMSCF3 as the source of CF2.
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Atom Recombination of Difluorocarbene Enables 3-Fluorinated Oxindoles from 2-Aminoarylketones Open
Open AccessCCS ChemistryRESEARCH ARTICLE1 May 2022Atom Recombination of Difluorocarbene Enables 3-Fluorinated Oxindoles from 2-Aminoarylketones Guan Zhang, Qianqian Shi, Mengyuan Hou, Kai Yang, Shihui Wang, Shuai Wang, Wangyang Li, Chaokun…
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Deconstrutive Difunctionalizations of Cyclic Ethers Enabled by Difluorocarbene to Access Difluoromethyl Ethers Open
Open AccessCCS ChemistryRESEARCH ARTICLE7 Dec 2022Deconstrutive Difunctionalizations of Cyclic Ethers Enabled by Difluorocarbene to Access Difluoromethyl Ethers Heyun Sheng, Jianke Su, Xue Li and Qiuling Song Heyun Sheng Institute of Next …
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In silico reaction screening with difluorocarbene for N-difluoroalkylative dearomatization of pyridines Open
Quantum chemical calculations are mainly regarded as a method for mechanistic studies in organic chemistry, whereas their use for the simulation of unknown reactions could greatly assist in reaction development. Here we report a strategy f…
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Stereospecific Transformations of Alkylboronic Esters Enabled by Direct Boron-to-Zinc Transmetalation Open
Chiral secondary organoboronic esters, when activated with t-butyllithium, are shown to undergo efficient stereoretentive transmetalation with either zinc acetate or zinc chloride. This reaction provides chiral secondary alkylzinc reagents…
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One-Pot Synthesis of Difluorobicyclo[1.1.1]pentanes from α-Allyldiazoacetates Open
Rapid access to 2,2-difluorobicylco[1.1.1]pentanes is enabled from an α-allyldiazoacetate precursor in a one-pot process through cyclopropanation to afford a 3-aryl bicyclo[1.1.0]butane, followed by reaction with difluorocarbene in the sam…
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Synthesis of 2‐Trifluoromethyl‐4‐aminoquinolines via Heating‐Promoted Multi‐component Reaction of CF<sub>3</sub>‐Imidoyl Sulfoxonium Ylides and Amines with Difluorocarbene as a C1 Synthon<sup>†</sup> Open
Comprehensive Summary A thermally‐induced multi‐component reaction of CF 3 ‐substituted imidoyl sulfoxonium ylides (TFISYs), amines and (triphenylphosphonio)difluoroacetate (PDFA) has been developed, allowing a facile access to 2‐trifluoro…
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Synthesis of Carbamoyl Fluorides Using a Difluorophosgene Surrogate Derived from Difluorocarbene and Pyridine <i>N</i>-Oxides Open
We report a method for the synthesis of carbamoyl fluorides from secondary amines using bench-stable, inexpensive, and readily accessible starting materials that, when combined, yield a surrogate for toxic difluorophosgene (COF2) gas. In c…
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Difluorocarbene-induced [1,2]- and [2,3]-Stevens rearrangement of tertiary amines Open
The [1,2]- and [2,3]-Stevens rearrangements are one of the most fascinating chemical bond reorganization strategies in organic chemistry, and they have been demonstrated in a wide range of applications, representing a fundamental reaction …
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Insertion of Carbenes into Deprotonated nido-Undecaborane, B11H13(2-) Open
We have examined the insertion of carbenes carrying leaving groups into the [nido-B11H13]2− dianion to form the [closo-1-CB11H12]− anion. The best procedure uses CF3SiMe3 and LiCl as the source of CF2. It is simple, convenient and scalable…
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Synthesis of Gold(I)−Trifluoromethyl Complexes and their Role in Generating Spectroscopic Evidence for a Gold(I)−Difluorocarbene Species Open
Readily prepared and bench‐stable [Au(CF 3 )(NHC)] compounds were synthesized by using new methods, starting from [Au(OH)(NHC)], [Au(Cl)(NHC)] or [Au(L)(NHC)]HF 2 precursors (NHC=N‐heterocyclic carbene). The mechanism of formation of these…
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Construction of Thienothiophene and Thienofuran Ring Systems via Ring Expansion of Difluorothiiranes Generated from Dithioesters Open
The reaction of aryl thiophene-2-carbodithioates or thiophene-3-carbodithioates with difluorocarbene generated from BrCF2CO2Li/molecular sieves 4A produced arylsulfanylated 2,2-difluoro-3-thienylthiiranes. In the presence of lithium ion, t…
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Synthesis of organic liquid crystals containing selectively fluorinated cyclopropanes Open
This paper describes the synthesis of a series of organic liquid crystals (LCs) containing selectively fluorinated cyclopropanes at their termini. The syntheses used difluorocarbene additions to olefin precursors, an approach which proved …
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A DFT Study on the Molecular Mechanism of Additions of Electrophilic and Nucleophilic Carbenes to Non-Enolizable Cycloaliphatic Thioketones Open
The molecular mechanisms of addition of dihalocarbenes and dimethoxycarbene to thioketones derived from 2,2,4,4-tetrmethylcyclobutane-1,3-dione were examined on the basis of the DFT wb97xd/6-311g(d,p)(PCM) calculations. Obtained results de…
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Oxidation of Difluorocarbene by Pyridine <span><i>N</i>‐Oxide</span> and Ensuing Access to Carbamoyl Fluorides<sup>†</sup> Open
Comprehensive Summary A practical one‐pot preparation of carbamoyl fluorides from easily obtained pyridine N ‐oxide, commercially available secondary amines and synthetically versatile difluorocarbene precursors (Ruppert‐Prakash reagent or…
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The Fluoride Method: Access to Silver(III) NHC Complexes Open
We have synthesized the first silver(III) carbene complexes, (CF 3 ) 3 Ag(NHC), by direct reaction of the silver(III) fluoride precursor complex [PPh 4 ][(CF 3 ) 3 AgF] with different imidazolium salts. This novel methodology circumvents t…
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Mechanochemical difluoromethylation of (thio)phenols and <i>N</i>‐heterocycles Open
Herein, we report a minimalistic protocol for the solvent‐free, mechanochemical difluoromethylation of (thio)phenols and N ‐heteroarenes using non‐ozone depleting chlorodifluoromethyl phenyl sulfone as a difluorocarbene source. This mechan…
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From intramolecular cyclization to intermolecular hydrolysis: TMSCF<sub>2</sub>Br-enabled carbonylation of aldehydes/ketones and amines to α-hydroxyamides Open
An unprecedented metal-free multicomponent reaction enables rapid and straightforward access to structurally diverse α-hydroxyamides from carbonyl compounds (aldehydes/ketones), difluorocarbene and amines.
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Palladium-catalyzed difluorocarbene transfer enables access to enantioenriched chiral spirooxindoles Open
We disclose herein an unprecedented Pd-catalyzed difluorocarbene transfer reaction, which assembles a series of structurally interesting chiral spiro ketones with generally over 90% ee. Commercially available BrCF 2 CO 2 K serves as the di…
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Mechanistic study of nucleophilic fluorination for the synthesis of fluorine-18 labeled fluoroform with high molar activity from <i>N</i>-difluoromethyltriazolium triflate Open
Route a: desired SN2 reaction of fluoride to form fluoroform with high molar activity; route b: side reaction to form methyl fluoride; route c: side reaction to form difluorocarbene to give fluoroform with lower molar activity.
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Unambiguous Spectroscopic Characterization of a Gold Difluorocarbene Open
Gold-(I) carbenes, defined as [LAuCR2]+, are key intermediates in catalysis. Their isolation is challenging due to the high electrophilic character of the carbene that cannot be tempered solely by π-backdonation from gold. Among those, th…
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Synthesis of Difluoroalkenes from Thiocarbonyl Compounds via Difluorothiiranes: Electrophilic Counterpart to Wittig-Type Difluoromethylidenation Open
The synthesis of 1,1-difluoro-1-alkenes was achieved by the treatment of dithioesters and thioketones with trimethylsilyl 2-fluorosulfonyl-2,2-difluoroacetate in the presence of a proton sponge catalyst, namely, 1,8-bis(dimethylamino)napht…
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Synthesis of Aryl‐Manganese(III) Fluoride Complexes via α‐Fluorine Elimination from CF<sub>3</sub> and Difluorocarbene Generation Open
We report the synthesis of cyclometalated monoaryl Mn III fluoro complexes using bis(trifluoromethyl)zinc reagent, Zn(CF 3 ) 2 (DMPU) 2 , under mild conditions via a reaction pathway that involves initial transmetalation followed by α‐fluo…
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Difluorocarbene-Enabled Synthesis of 3-Substituted-2-oxoindoles from <i>o-</i>Vinylanilines Open
A novel transition-metal-free protocol for the synthesis of 1-alkyl-3-(2-oxo-2-aryl/alkyl-ethyl)indolin-2-ones is developed.This work reveals that oxoindole skeletons can be directly constructed from ortho-vinylanilines and commercially av…