Au@ZnO Core–Shell: Scalable Photocatalytic Trifluoromethylation Using CF3CO2Na as an Inexpensive Reagent under Visible Light Irradiation

Regioselective Homolytic C2-H Borylation of Unprotected Adenosine and Adenine Derivatives via Minisci Reaction

A Minisci-type borylation of unprotected adenosine, adenine nucleotide, and adenosine analogues was successfully achieved through photocatalysis or thermal activation. Despite the challenges posed by the presence of two potential reactive sites (C2 and C8) in the purine motif, the unique nucleophilic amine-ligated boryl radicals effortlessly achieved excellent C2 site selectivity and simultaneously avoided the formation of multifunctionalized products. This protocol proved effective for the late-stage borylation of some important biomolecules as well as a few antiviral and antitumor drug molecules, such as AMP, cAMP, Vidarabine, Cordycepin, Tenofovir, Adefovir, GS-441524, etc. Theoretical calculations shed light on the site selectivity, revealing that the free energy barriers for the C2-Minisci addition are further lowered through the chelation of additive Mg2+ to N3 and furyl oxygen. This phenomenon has been confirmed by an IGMH analysis. Preliminary antitumor evaluation, derivation of the C2-borylated adenosine to other analogues with high-value functionalities, along with the CuAAC click reactions, suggest the potential application of this methodology in drug molecular optimization studies and chemical biology.

Electrochemical oxidative selective halogenation of pyrazolones for the synthesis of 4-halopyrazolones

An efficient and environmentally friendly electrochemical oxidative selective halogenation of pyrazolones has been developed under conditions free of metals, external oxidants, and external supporting electrolytes. The reaction demonstrates good functional group tolerance and maintains high efficiency in large-scale synthesis, yielding moderate to excellent yields of the desired 4-halopyrazolones. This method provides a green and convenient route for the direct installation of a halogen moiety into bioactive pyrazolone derivatives, which can be utilized in a myriad of applications.

Direct Decarboxylation of Trifluoroacetates Enabled by Iron Photocatalysis

Trifluoroacetates are the most abundant and accessible sources of trifluoromethyl groups, which are key components in pharmaceuticals and agrochemicals. The generation of trifluoromethyl reactive radicals from trifluoroacetates requires their decarboxylation, which is hampered by their high oxidation potential. This constitutes a major challenge for redox-based methods, because of the need to pair the redox potentials with trifluoroacetate. Here we report a strategy based on iron photocatalysis to promote the direct photodecarboxylation of trifluoroacetates that displays reactivity features that escape from redox limitations. Our synthetic design has enabled the use of trifluoroacetates for the trifluoromethylation of more easily oxidizable organic substrates, offering new opportunities for late-stage derivatization campaigns using chemical feedstocks, Earth-abundant catalysts, and visible-light.

Recent Advances in Visible Light-Mediated Radical Fluoro-alkylation, -alkoxylation, -alkylthiolation, -alkylselenolation, and -alkylamination

In the last few years, many reagents and protocols have been developed to allow for the efficient fluorofunctionalization of a diverse set of scaffolds ranging from alkanes, alkenes, alkynes, and (hetero)arenes. The concomitant rise of organofluorine chemistry and visible light-mediated synthesis have synergistically expanded the fields and have mutually benefitted from developments in both fields. In this context, visible light driven formations of radicals containing fluorine have been a major focus for the discovery of new bioactive compounds. This review details the recent advances and progress made in visible light-mediated fluoroalkylation and heteroatom centered radical generation.

Ru-Bipyridine Entrapped in the Supercages of EMC-1 Faujasite as Catalyst for the Trifluoromethylation of Arenes

Trifluoromethyl (CF₃) groups are versatile structural motifs especially in the field of agrochemicals and pharmaceuticals. However, current trifluoromethylation reactions are generally associated with stoichiometric amounts of transition metals/metal oxidants, homogeneous catalysts, high temperatures, and expensive trifluoromethylating agents. In this work, the homogeneous photocatalyst Ru(bipy)₃²⁺ is entrapped in the pores of a faujasite support (EMC-1) via a "ship-in-a-bottle" strategy. The formation of the coordination compound was confirmed by Fourier transform infrared (FTIR), UV-Vis spectroscopy, and X-ray absorption spectroscopy (XAS). Due to its high stability toward acidified environments, this single-site heterogeneous catalyst is suitable for the trifluoromethylation of synthetically interesting (hetero)arenes under visible-light irradiation at room temperature. Furthermore, the heterogeneous catalyst could efficiently be reused for at least three times with minimal catalyst leaching/deactivation.

A straightforward access to trifluoromethylated natural products through late-stage functionalization

This review summarizes the applications of late-stage strategies in the direct trifluoromethylation of natural products in the past ten years, with particular emphasis on the reaction model of each method.

Au–Pd@ZnO alloy nanoparticles: a promising heterogeneous photocatalyst toward decarboxylative trifluoromethylation under visible-light irradiation

Au–Pd@ZnO alloy nanoparticles have promising potential as heterogeneous photocatalysts for decarboxylative trifluoromethylation reactions under visible light irradiation.

An Efficient Approach to 2-CF3-Indoles Based on ortho-Nitrobenzaldehydes

The catalytic olefination reaction of 2-nitrobenzaldehydes with CF3CCl3 afforded stereoselectively trifluoromethylated ortho-nitrostyrenes in up to 88% yield. The reaction of these alkenes with pyrrolidine permits preparation of α-CF3-β-(2-nitroaryl) enamines. Subsequent one pot reduction of nitro-group by Fe-AcOH-H2O system initiated intramolecular cyclization to afford 2-CF3-indoles. Target products can be prepared in up to 85% yields. Broad synthetic scope of the reaction was shown as well as some followed up transformations of 2- CF3-indole.

Boron-doped TiO2 (B-TiO2): visible-light photocatalytic difunctionalization of alkenes and alkynes

Boron-doped TiO₂ (B-TiO₂) was prepared, characterized, and applied as a reusable, inexpensive, and available heterogeneous nanophotocatalyst under visible light for the synthesis of phenacyl thiocyanates.

A green and energy-efficient photocatalytic process for the accelerated synthesis of lactic acid esters using functionalized quantum dots

Sulphonated-grafted-titania quantum dot catalyzed green and energy-efficient photochemical process for the synthesis of valuable lactic acid esters at ambient temperature.