ChemInform Abstract: Silver(I)‐Catalyzed N‐Trifluoroethylation of Anilines and O‐Trifluoroethylation of Amides with 2,2,2‐Trifluorodiazoethane.

Luo, Haiqing; Wu, Guojiao; Zhang, Yan; Wang, Jianbo

doi:10.1002/chin.201613071

Cited by 4 publications

(4 citation statements)

References 19 publications

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“…On the basis of these observations and related precedents ( Brogan and Zercher, 1996 , Liu et al., 2018 ), a plausible mechanism for this formal C−C insertion process is proposed in Scheme 4 . Initially, NaH promotes decomposition of the N -nosylhydrazone 1 to generate an unstable donor-type diazo species I , which then reacts with the silver enolate II formed from reaction of AgOTf with 1,3-dicarbonyls to give a key intermediate silver carbenoid III ( Thompson and Davies, 2007 , Caballero et al., 2011 , Luo et al., 2015 ). Intramolecular cyclopropanation of the enolate alkene by a carbene transfer-insertion affords cyclopropane IV , which undergoes a ring-opening retro-aldol process to generate intermediate V ( Cavitt et al., 2014 ).…”

Section: Resultsmentioning

confidence: 99%

Silver-Catalyzed Regio- and Stereoselective Formal Carbene Insertion into Unstrained C−C σ-Bonds of 1,3-Dicarbonyls

et al. 2018

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SummaryA regio- and stereoselective silver-catalyzed formal carbene insertion into 1,3-dicarbonyls has been developed, using N-nosylhydrazones as diazo surrogates. Two new C−C bonds are constructed at the carbenic carbon center through the selective cleavage of the C−C(=O) σ-bond of acyclic 1,3-dicarbonyls, enabling the preparation of various synthetically useful polysubstituted γ-diketones, γ-ketoesters, and γ-ketoamides in high yields. The in situ formation of a donor-acceptor cyclopropane, via reaction of the enolate of the 1,3-dicarbonyl with an electrophilic silver carbenoid, is proposed as a key process in the catalytic cycle.

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Section: Resultsmentioning

confidence: 99%

Silver-Catalyzed Regio- and Stereoselective Formal Carbene Insertion into Unstrained C−C σ-Bonds of 1,3-Dicarbonyls

et al. 2018

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“…420 Wang and co-workers reported a silver(I)-catalyzed reaction of anilines with 2,2,2-trifluorodiazoethane, providing a series of Ntrifluoroethylated anilines 930 in good to excellent yields. 421 This reaction most likely involves the formation of a silver-carbene intermediate 931, followed by migratory insertion of metal carbene to the Ag−N bond and protonation to produce the desired product. The similar reaction conditions can also be applied in the O-trifluoroethylation of amides to produce trifluoroethyl imidates 932, in which the migratory insertion of metal carbene 933 to the Ag−O bond was proposed as the key step.…”

Section: Pt-and Ag-catalyzed Reactionsmentioning

confidence: 99%

Transition-Metal-Catalyzed Cross-Couplings through Carbene Migratory Insertion

2017

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Transition-metal-catalyzed cross-coupling reactions have been well-established as indispensable tools in modern organic synthesis. One of the major research goals in cross-coupling area is expanding the scope of the coupling partners. In the past decade, diazo compounds (or their precursors N-tosylhydrazones) have emerged as nucleophilic cross-coupling partners in C-C single bond or C═C double bond formations in transition-metal-catalyzed reactions. This type of coupling reaction involves the following general steps. First, the organometallic species is generated by various processes, including oxidative addition, transmetalation, cyclization, C-C bond cleavage, and C-H bond activation. Subsequently, the organometallic species reacts with the diazo substrate to generate metal carbene intermediate, which undergoes rapid migratory insertion to form a C-C bond. The new organometallic species generated from migratory insertion may undergo various transformations. This type of carbene-based coupling has proven to be general: various transition metals including Pd, Cu, Rh, Ni, Co, and Ir are effective catalysts; the scope of the reaction has also been extended to substrates other than diazo compounds; and various cascade processes have also been devised based on the carbene migratory insertion. This review will summarize the achievements made in this field since 2001.

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“…Unfortunately, while many C–H trifluoroethylation methods have been reported 33 34 35 36 37 38 , there are fewer reagents for the trifluoroethylation of amines ( Fig. 1a , left) 39 40 . The most widely used method involves LiAlH 4 or borane reduction of trifluoromethylamides generated using trifluoroacetic anhydride ( Fig.…”

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confidence: 99%

A practical and catalyst-free trifluoroethylation reaction of amines using trifluoroacetic acid

2017

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Amines are a fundamentally important class of biologically active compounds and the ability to manipulate their physicochemical properties through the introduction of fluorine is of paramount importance in medicinal chemistry. Current synthesis methods for the construction of fluorinated amines rely on air and moisture sensitive reagents that require special handling or harsh reductants that limit functionality. Here we report practical, catalyst-free, reductive trifluoroethylation reactions of free amines exhibiting remarkable functional group tolerance. The reactions proceed in conventional glassware without rigorous exclusion of either moisture or oxygen, and use trifluoroacetic acid as a stable and inexpensive fluorine source. The new methods provide access to a wide range of medicinally relevant functionalized tertiary β-fluoroalkylamine cores, either through direct trifluoroethylation of secondary amines or via a three-component coupling of primary amines, aldehydes and trifluoroacetic acid. A reduction of in situ-generated silyl ester species is proposed to account for the reductive selectivity observed.

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ChemInform Abstract: Silver(I)‐Catalyzed N‐Trifluoroethylation of Anilines and O‐Trifluoroethylation of Amides with 2,2,2‐Trifluorodiazoethane.

Cited by 4 publications

References 19 publications

Silver-Catalyzed Regio- and Stereoselective Formal Carbene Insertion into Unstrained C−C σ-Bonds of 1,3-Dicarbonyls

Silver-Catalyzed Regio- and Stereoselective Formal Carbene Insertion into Unstrained C−C σ-Bonds of 1,3-Dicarbonyls

Transition-Metal-Catalyzed Cross-Couplings through Carbene Migratory Insertion

A practical and catalyst-free trifluoroethylation reaction of amines using trifluoroacetic acid

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