Synthesis of N-(α-fluorovinyl)azoles by the reaction of difluoroalkenes with azoles

Domino C-F Bond Activation of the CF3 Group: Synthesis of Fluorinated Dibenzo[a,c][7]annulenes from 2-(Trifluoromethyl)-1-alkenes and 2,2'-Diceriobiaryls

The construction of ring-fluorinated seven-membered carbocycles was readily achieved via the domino S_N2'-type/S_NV reaction between 2-(trifluoromethyl)-1-alkenes and 1,4-carbodianions. The S_N2'-type reaction of 2-(trifluoromethyl)-1-alkenes with 2,2'-diceriobiaryls generated the intermediary 1,1-difluoro-1-alkenes bearing a monoceriobiaryl moiety, which in turn underwent intramolecular S_NV reaction to afford fluorinated 5H-dibenzo[a,c][7]annulenes.

N-Heterocyclic carbene-catalyzed stereoselective construction of olefinic carbon–sulfur bonds via cross-coupling reaction of gem-difluoroalkenes and thiols

A novel organocatalytic olefinic carbon–sulfur bond forming reaction was developed.

New one-pot synthesis of N-fused isoquinoline derivatives by palladium-catalyzed C-H arylation: potent inhibitors of nucleotide pyrophosphatase-1 and -3

Various N-fused isoquinoline derivatives were synthesized using a new one-pot reaction of 1-bromo-2-(2,2-difluorovinyl)benzenes with N-H group containing heterocycles followed by intramolecular palladium-catalyzed C-H arylation. The method described gives convenient access to diverse structures of N-fused polycyclic isoquinolines. Sixteen of the synthesized compounds were screened as potential human nucleotide pyrophosphatase/phosphodiesterase 1 and 3 (h-NPP-1 and h-NPP-3) inhibitors. The most effective h-NPP-1 inhibitor showed an IC₅₀ value as high as 0.36 ± 0.06 μM, whereas the most potent h-NPP-3 inhibitor posessed an inhibitory value of 0.48 ± 0.01 μM. Kinetic and molecular docking studies of both most effective inhibitors were carried out.

One-pot syntheses of N-(α-fluorovinyl)azole derivatives from N-(diphenylmethylene)-2,2,2-trifluoroethanamine

N-(Diphenylmethylene)-2,2,2-trifluoroethanamine acts as a versatile fluorine-containing building block, and from which N-(α-fluorovinyl)azole derivatives were prepared in a one-pot process.

Synthesis and antiproliferative efficiency of novel bis(imidazol-1-yl)vinyl-1,2,4-oxadiazoles

A new class of bis(imidazol)vinyl-1,2,4-oxadiazoles were synthesised and their anti-proliferative efficiency was tested against HCT116 and A549 cancer cell lines.

Rhodium-catalysed C(sp(2))-C(sp(2)) bond formation via C-H/C-F activation

Fluoroalkenes represent a class of privileged structural motifs, which found widespread use in medicinal chemistry. However, the synthetic access to fluoroalkenes was much underdeveloped with previous reported methods suffering from either low step economy or harsh reaction conditions. Here we present a Rh^III-catalysed tandem C–H/C–F activation for the synthesis of (hetero)arylated monofluoroalkenes. The use of readily available gem-difluoroalkenes as electrophiles provides a highly efficient and operationally simple method for the introduction of α-fluoroalkenyl motifs onto (hetero)arenes under oxidant-free conditions. Furthermore, the employment of alcoholic solvent and the in-situ generated hydrogen fluoride are found to be beneficial in this transformation, indicating the possibility of the involvement of hydrogen bond activation mode with regards to the C–F bond cleavage step.

Fluoroalkenes are found widely in biologically active compounds, but their introduction can be difficult or laborious. Here, the authors report a C–H/C–F activation strategy to introduce monofluoroalkenes into organic molecules in one step with good to excellent yields.

E- or Z-Selective synthesis of 4-fluorovinyl-1,2,3-triazoles with fluorinated second-generation Julia-Kocienski reagents

A highly modular approach to N-substituted 4-(1-fluorovinyl)triazoles is described. In situ desilylation and Cu-catalyzed ligation reaction of TMS-protected α-fluoropropargyl benzothiazole sulfone with aryl, alkyl, and metallocenyl azides furnished second-generation Julia-Kocienski reagents in good to excellent yields. Condensation reactions of these reagents with aldehydes can be tuned to yield E or Z-alkenes selectively. Under mild conditions with DBU as the base, reactions of aldehydes furnished E-alkenes as the major isomer. On the other hand, in condensation reactions with LHMDS as the base and in appropriate solvents, both aldehydes and ketones reacted to yield fluoroalkenes with Z-selectivity. Stereochemical assignment of E/Z olefins obtained in the reaction of a ketone with two Julia reagents was performed via X-ray crystallographic analysis and comparisons of NMR data. The method allows efficient and ready diversification of the N1-substituent and substituents at the double bond.

Synthesis of fluorovinyl aryl ethers by a three-component reaction of gem-difluoroalkenes with arylboronic acids and oxygen

An efficient three-component reaction for the synthesis of fluorovinyl aryl ethers from gem-difluoroalkenes, arylboronic acids and oxygen is described.

Base-mediated direct fluoroalkenylation of 2-phenyl-1,3,4-oxadiazole, benzothiazole and benzoxazole with gem-difluoroalkenes

Direct α-fluorovinylation of 2-phenyl-1,3,4-oxadiazole, benzothiazole and benzoxazole with gem-difluoroalkenes under the assistance of KHMDS or NaH at room temperature was developed.

Base-promoted direct and highly selective alkynylation of electron-deficient octafluorotoluene

Experimental and theoretical studies are reported on the base-promoted direct alkynylation of octafluorotoluene via highly selective C–F bond cleavage.

Nickel-catalyzed Suzuki–Miyaura type cross-coupling reactions of (2,2-difluorovinyl)benzene derivatives with arylboronic acids

An unprecedented highly stereoselective example of nickel-catalyzed Suzuki–Miyaura type cross-coupling reactions of (2,2-difluorovinyl)benzene derivatives with arylboronic acids was developed.

A three-component synthesis of aryl(heteroaryl)acylamides

α-Heteroarylamides of diverse structures are assembled in a three-component reaction of azole or azineN-oxides, 1,1-difluorostyrenes and amines.

Difluoromethyl 2-pyridyl sulfone: a versatile carbonyl gem-difluoroolefination reagent

The gem-difluoroolefination of carbonyl compounds with difluoromethyl 2-pyridyl sulfone (2-PySO₂CF₂H) has been summarized in this tutorial account.