A mild and efficient synthesis of N-substituted-2-fluoroindole derivatives was achieved via Buchwald–Hartwig couplings and a sequential, base-promoted intramolecular nucleophilic reaction−β-fluorine elimination. By employing easily obtained gem-difluorostyrenes and primary arylamines, the scope, advantages, and limitations of this reaction were well investigated. Furthermore, this strategy distinguishes itself by high modularity, operational simplicity, and a wide substrate scope, giving rise to a broad array of 2-fluoroindole derivatives in moderate to excellent yields.

An AgI-mediated ethoxycarbonyldifluoromethylation of isocyanides has been developed. This radical cascade reaction involves the addition of difluoromethylene radical to the isocyanide functionality, and subsequent homolytic aromatic substitution to give difluoromethylated phenanthridines with a good functional-group tolerance.

AbstractN2-Selective autocatalytic ditriazolylation reactions of cyclopropenones and tropone with N1-sulfonyl-1,2,3-triazoles are reported for the first time. In contrast to previous methods for preparing N2-substituted bis(1,2,3-triazolyl) compounds, the present reaction achieved ditriazolylation in one step under simple and user-friendly conditions with a wide substrate scope. A plausible mechanism has been proposed relying on preliminary mechanistic investigations.

Copper-catalyzed gem-difluoromethylenation of the C(sp2)–H bonds of alkenes with high functional group tolerance has been developed. This protocol is the first to efficiently achieve gem-difluoromethylenation of C(sp2)–H bonds of unactivated aliphatic terminal olefins and can be applied in a reaction cascade to achieve gem-difluoromethylenation/cyclization of alkenes.

Manganese-mediated/-catalyzed oxidative carboazidation of acrylamides was developed for the synthesis of various azido oxindoles in 32% to 99% yields. tert-Butyl peroxybenzoate (TBPB) was used as an oxidant for the Mn-catalyzed method. And a Mn(II)/Mn(IV)/Mn(III) catalysis cycle via a stepwise or concerted regeneration of high-valent manganese was proposed for this protocol. This reaction system exhibits great functional group tolerance.

A silver-catalyzed oxidative decarboxylative gem-difluoromethylenation of difluoroacetates with activated alkenes under mild reaction conditions has been developed. This radical cascade reaction provides a new method for the construction of a variety of gem-difluoromethylenated oxindoles.

A bio-memristor fabricated with ferritin exhibits novel resistive switching characteristics wherein memory switching and threshold switching are made steadily coexistent and inter-convertible through controlling the magnitude of compliance current presets.

A mild, versatile and efficient method for the silver(I)-catalyzed oxidative decarboxylative gem-difluoromethylenation has been developed. The radical cascade reaction comprises the addition of an oxidatively generated difluoromethylene radical to the isonitrile functionality and subsequent homolytic aromatic substitution. It provides a novel and efficient access to the C–CF2 bond formation.

Efficient direct gem-difluoromethylenation of an sp3-hybridized carbon center in benzyl bromides using benzo-1,3-azolic (oxa-, thia- or aza-) difluoromethyl bromides for construction of a CH2–CF2 linkage has been developed through radical/radical C–C cross-coupling via two separate single electron transfer processes (SET) under the promotion of different copper sources.

•Trifluoromethyl-pyrazolo[3, 4-b]quinolines (PQs) were synthesized and characterized.•DFT calculation, electrochemical, and photophysical properties were discussed.•A linear relationship of dipole moments versus Stokes shifts was demonstrated.•These PQs showed potential applications in organic light-emitting diodes (OLED).Organic dyes containing trifluoromethylated-pyrazolo[3, 4-b]quinoline were synthesized by using condensation reaction between substituted pyrazolo-4-formaldehyde and aryl amines in moderate yields. Quantum calculation, electrochemical, photophysical, and electroluminescent properties were discussed in detail. Electron-withdrawing groups at 6-position of dyes stabilized the LUMO energy levels significantly resulting in red-shifted absorption/emission spectra. Addition of electron-donating group destabilized the HOMO strongly and the LUMO energy levels slightly resulting in red-shifted absorption maxima, but in blue-shifted emission maxima. Experimental and quantum calculation results are presented here to explain this unusual phenomenon. A linear relationship of dipole moments versus Stokes shifts is obtained for these fluorophores, where the increase of dipole moment is accompanied by a decrease in Stokes shift. Organic light-emitting diodes based on selected dyes showed emission at 456 nm, maximum external quantum efficiency at 1.43%, and current efficiency at 1.95 cd/A.A linear relationship of dipole moments versus Stokes shifts is obtained for Pyrazolo[3, 4-b]Quinoline derivatives, where the increase of dipole moment is accompanied by a decrease in Stokes shift.

Cu(II)-catalyzed aromatic C–H azidation with azido-benziodoxolone under mild conditions has been described. The primary amine exhibits an excellent ortho-directing effect, providing ortho-azidated anilines as the sole products.

A mild, versatile and efficient method for the regioselective hydrodifluoromethylation of unactivated alkenes has been developed. This Ag-mediated Csp3–CF2 bond forming reaction provides easy access to a variety of vicinal α-difluoroacetate-containing alkanes.

A copper-mediated gem-difluoromethylenation of aryl, heteroaryl and vinyl boronic acids with bromodifluoromethylated oxazole or thiazole derivatives has been developed. This novel reaction showed an excellent functional group tolerance and wide substrate scope, providing facile access to practical application in drug discovery and development.

A class of chiral bifunctional N-prolyl sulfinamide and its TFA salts were prepared and proven to be effective for catalyzing the aldol reaction under solvent-free conditions. In general, the corresponding aldol adducts were obtained with high to excellent yields, and satisfactory diastereo-selectivities and enantioselectivities. A matching effect between chiral proline and sulfinamide moieties was observed in the catalysts. The enantioswitching of both enantiomers in the asymmetric aldol synthesis is found to be dominated by the prolyl moiety.

A series of twisted fluorenyl anthracenes linked by a rigid sp3-hybridized carbon atom, containing an end-capping aryl substituent at either the C2-position of fluorene or at the C10-position of anthracene, have been synthesized and characterized. These materials exhibited good thermal stabilities and amorphous properties. Theoretical calculations and X-ray diffraction studies revealed that the six blue emitters possess non-coplanar structures to suppress intermolecular interactions. The relationship between the chemical structures with different end-capping groups and the electroluminescent properties has been investigated. Organic light-emitting diodes utilizing 9-(2-phenyl-9H-fluoren-9-yl) anthracene as the emitter exhibited deep-blue emissions CIE x, y (0.166, 0.153) with a current efficiency of 1.47 cd/A, external quantum efficiency of 1.84% at 20 mA/cm2 and a maximum brightness of 3013 cd/m2 at 11 V. It was found that the introduction of the aryl substituents to the C2 position of fluorene could improve the performance of OLEDs based on C9-fluorenyl anthracenes.Graphical abstractHighlights► Six new C9-fluorenyl anthracenes were prepared. ► All have high glass transition temperatures above 100 °C. ► Better performance of OLEDs based on C9-fluorenyl anthracenes with C2-substituents. ► An efficiency (1.47 cd/A) and an external quantum efficiency (1.84%) at 20 mA/cm2.

Multi-functionalized β-trifluoromethyl and β-difluoromethyl substituted (Z)-α,β-dehydro α-amino esters have been successfully prepared from N-protected fluorinated threonine ester. Applications of this new fluorine-containing building block to the synthesis of biologically important fluorinated cylcopropyl α-amino esters and dihydrooxazole ester have also been reported.

A novel method to access triazole-fused spiro-guanidine from the reaction of isothiocyanate tethered N-sulfonyl-1,2,3-triazoles and amine has been developed. The reactions proceeded through a two-component tandem reaction, including nucleophilic addition, base-assisted intramolecular (or intermolecular) nucleophilic substitution and subsequent intramolecular nucleophilic addition–elimination process. A wide range of protected oxindole skeletons and amines are well-tolerated.

Copper-catalyzed gem-difluoromethylenation of the C(sp2)–H bonds of alkenes with high functional group tolerance has been developed. This protocol is the first to efficiently achieve gem-difluoromethylenation of C(sp2)–H bonds of unactivated aliphatic terminal olefins and can be applied in a reaction cascade to achieve gem-difluoromethylenation/cyclization of alkenes.

A silver-catalyzed oxidative decarboxylative gem-difluoromethylenation of difluoroacetates with activated alkenes under mild reaction conditions has been developed. This radical cascade reaction provides a new method for the construction of a variety of gem-difluoromethylenated oxindoles.

A mild, versatile and efficient method for the regioselective hydrodifluoromethylation of unactivated alkenes has been developed. This Ag-mediated Csp3–CF2 bond forming reaction provides easy access to a variety of vicinal α-difluoroacetate-containing alkanes.

A copper-mediated gem-difluoromethylenation of aryl, heteroaryl and vinyl boronic acids with bromodifluoromethylated oxazole or thiazole derivatives has been developed. This novel reaction showed an excellent functional group tolerance and wide substrate scope, providing facile access to practical application in drug discovery and development.

Cu(II)-catalyzed aromatic C–H azidation with azido-benziodoxolone under mild conditions has been described. The primary amine exhibits an excellent ortho-directing effect, providing ortho-azidated anilines as the sole products.

Efficient direct gem-difluoromethylenation of an sp3-hybridized carbon center in benzyl bromides using benzo-1,3-azolic (oxa-, thia- or aza-) difluoromethyl bromides for construction of a CH2–CF2 linkage has been developed through radical/radical C–C cross-coupling via two separate single electron transfer processes (SET) under the promotion of different copper sources.

A mild, versatile and efficient method for the silver(I)-catalyzed oxidative decarboxylative gem-difluoromethylenation has been developed. The radical cascade reaction comprises the addition of an oxidatively generated difluoromethylene radical to the isonitrile functionality and subsequent homolytic aromatic substitution. It provides a novel and efficient access to the C–CF2 bond formation.

A bio-memristor fabricated with ferritin exhibits novel resistive switching characteristics wherein memory switching and threshold switching are made steadily coexistent and inter-convertible through controlling the magnitude of compliance current presets.