Mechanistic study of visible light-driven CdS or g-C3N4-catalyzed C H direct trifluoromethylation of (hetero)arenes using CF3SO2Na as the trifluoromethyl source

Cu-catalyzed convenient synthesis of 2-trifluoromethyl benzimidazoles via cyclization of o-phenylenediamines with hexafluoroacetylacetone

An efficient and convenient method for the synthesis of 2-trifluoromethyl benzimidazoles is described in this paper. The cyclization reaction of various o-phenylenediamines with hexafluoroacetylacetone proceeded smoothly in the presence of Cu2O as the catalyst to produce 2-trifluoromethyl benzimidazoles in satisfactory to excellent yields (up to >99% yield). The CF3 source, hexafluoroacetylacetone, acted not only as cyclization partner, but also acted as a ligand for the Cu catalyst. Various synthetically useful functional groups, such as halogen atoms, cyano, and methoxycarbonyl groups, remained intact during the cyclization reactions. The reaction mechanism was thoroughly investigated and was determined to involve a seven-membered cyclic diimine intermediate.

Nanostructured Carbon Nitride for Continuous-Flow Trifluoromethylation of (Hetero)arenes

Efficient catalytic methods for the trifluoromethylation of (hetero)arenes are of particular importance in organic and pharmaceutical manufacturing. However, many existing protocols rely on toxic reagents and expensive or sterically hindered homogeneous catalysts. One promising alternative to conduct this transformation involves the use of carbon nitride, a non-toxic photocatalyst prepared from inexpensive precursors. Nonetheless, there is still little understanding regarding the interplay between physicochemical features of this photocatalyst and the corresponding effects on the reaction rate. In this work, we elucidate the role of carbon nitride nanostructuring on the catalytic performance, understanding the effect of surface area and band gap tuning via metal insertion. Our findings provide new insights into the structure-function relationships of the catalyst, which we exploit to design a continuous-flow process that maximizes catalyst-light interaction, facilitates catalyst reusability, and enables intensified reaction scale-up. This is particularly significant given that photocatalyzed batch protocols often face challenges during industrial exploitation. Finally, we extrapolate the rapid and simplified continuous-flow method to the synthesis of a variety of functionalized heteroaromatics, which have numerous applications in the pharmaceutical and fine chemical industries.

A 2D Dy-based metal-organic framework derived from benzothiadiazole: structure and photocatalytic properties

A 2D Dy(III) metal-organic layer (MOL 1) was synthesized under solvothermal conditions. Structural analysis suggests that the Dy(III) ions in each one-dimensional (1D) arrangement are evenly arranged in the form of broken lines. The 1D chains are linked to one another via ligands to form a 2D layer that generates a 2D surface with elongated apertures. The photocatalytic activity study suggests that MOL 1 exhibits good catalytic activity in flavonoids by the formation of an O₂˙^- radical as an intermediate. This is the first reported method of synthesizing flavonoids using chalcones.

Copper-mediated three-component synthesis of 2-trifluoromethyl benzimidazoles

A copper-mediated three-component reaction of o-iodoanilines, anilines, and ethyl trifluoropyruvate is reported. The transformation allows diverse scopes on both o-iodoanilines and anilines delivering various 2-trifluoromethylbenzimidazole products in moderate to good...

Efficient photocatalytic chemoselective and stereoselective C–C bond formation over AuPd@N-rich carbon nitride

High unsymmetrical chemoselective Ullmann biaryl products and satisfactory Z-type stereoselective Heck reaction products could be achieved through changing the visible light color over AuPd@N-Rich carbon nitride under mild conditions.