Photoassisted Cross-Coupling Reaction of α-Chlorocarbonyl Compounds with Arylboronic Acids

1,2-Acylcyanation of Styrenes by Photoinduced Nickel Catalysis to Generate Acyl Radicals from Acyl Fluorides

We report herein a photoinduced nickel-catalyzed 1,2-acylcyanation of styrenes with acyl fluorides and trimethylsilyl cyanide (TMSCN). Nickel(II) acyl complexes, formed from nickel(0) complexes and acyl fluorides, are photoexcited to generate acyl radicals via a ligand-to-metal charge transfer (LMCT) process. This transformation proceeds under mild conditions and thus can be applied to the late-stage functionalization (LSF) of natural product derivatives. Synthetic derivatizations show the utility of the products. The preparation of aza-DIPYs is also demonstrated.

Thermal Compatibility of New ACEI Derivatives with Popular Excipients Used to Produce Solid Pharmaceutical Formulations

Background/Objectives: Increasing drugs' stability and adequately protecting them against degradation will ensure a decrease in their price and broader availability of pharmaceutical substances. This is of great importance, especially for drugs used to treat the most common diseases in the population, such as hypertension. The study examined two newly synthesized substances from the angiotensin I-converting enzyme inhibitor (ACEI) group as potential drugs. ACEIs are among the leading drugs used in the treatment of hypertension in the world. The chemical modifications of the tested substances applied concerned the places most susceptible to degradation. The presented work analyzed the compatibility of new derivatives with selected excipients used in pharmacy. Methods: Thermogravimetric (TGA) and differential thermal analyses (c-DTA) were used as the main methods. In addition, non-thermal methods such as colorimetry analysis, Fourier-transform infrared (FTIR) and UV spectroscopy were used. Results: Based on the conducted studies, it can be concluded that the incompatibility of IND-1 with glucose anhydrous and lactose monohydrate occurs only when the mixture is stored at higher temperatures. For the remaining IND-1 and IND-2 mixtures with excipients, compatibility was demonstrated. Conclusions: The obtained results confirmed the usefulness of the applied thermal analyses (TGA and c-DTA) for assessing the compatibility of the tested potential drugs with excipients. However, in the case of incompatibility reactions of substances occurring under the influence of elevated temperatures, such as the Maillard reaction, it is necessary to use non-thermal methods to obtain the right result.

Photoinduced Pd-Catalyzed Intramolecular 6-endo Heck Reaction of Alkyl Halides

A novel photocatalytic palladium-induced 6-endo-selective alkyl Heck reaction of unactivated alkyl iodides and alkyl bromides has been described. This strategy facilitates the gentle and efficient synthesis of a variety of 5-phenyl-1,2,3,6-tetrahydropyridine derivatives. It demonstrates a broad substrate tolerance and excellent 6-endo selectivity. Unlike the high-temperature requirements of traditional alkyl Heck reactions, this transformation efficiently proceeds at room temperature and shows significant promise for industrial-scale applications. Mechanistic investigations reveal that this alkyl Heck reaction proceeds via a hybrid palladium-radical process.

Recent Advances in Visible Light Induced Palladium Catalysis

Visible light-induced Pd catalysis has emerged as a promising subfield of photocatalysis. The hybrid nature of Pd radical species has enabled a wide array of radical-based transformations otherwise challenging or unknown via conventional Pd chemistry. In parallel to the ongoing pursuit of alternative, readily available radical precursors, notable discoveries have demonstrated that photoexcitation can alter not only oxidative addition but also other elementary steps. This Minireview highlights the recent progress in this area.

Design and synthesis of novel PPO-inhibiting pyrimidinedione derivatives safed towards cotton

Developing innovative and effective herbicides is of utmost importance since weed management has become a worldwide agricultural production concern, resulting in severe economic losses every year. In this study, a series of new pyrimidinedione compounds were developed via combination of pyrimidinediones with N-phenylacetamide moiety. The herbicidal activity test (37.5-150 g of ai/ha) indicated that most of the new derivatives exhibited excellent herbicidal activity against dicotyledonous weeds, but less against grasses. Among them, compound 34 was identified as the best postemergence herbicidal activities against six species of weeds (Amaranthus retrof lexus, AR; Abutilon theophrasti, AT; Veronica polita, VP; Echinochloa crusgalli, EC; Digitaria sanguinalis, DS; Setaria viridis, SV), which were comparable to the commercial control agent saflufenacil (≥90%). The protoporphyrinogen oxidase (PPO; EC. 1.3.3.4) activity experiment suggested that compound 34 could significantly reduce the PPO content in weeds, the relative expression levels of the PPO gene were verified by real-time quantitative polymerase chain reaction (RT-qPCR), and the results were consistent with the trend of the enzyme activity data. Molecular docking showed that compound 34 could occupy the PPO enzyme catalytic substrate pocket, which played an excellent inhibitory effect on the activity of receptor protein. Meanwhile, the tolerance of compound 34 to cotton was better than that of the commercial agent saflufenacil at 150 g of ai/ha. Thus, compound 34 exhibits the potential to be a new PPO herbicide for weed control in cotton fields. This study provided a basis for the subsequent structural modification and mechanism research of pyrimidinedione derivatives.

Carbonyl-Assisted Iridium-Catalyzed C-H Amination Using 2,2,2-Trichloroethoxycarbonyl Azide

The carbonyl-directed, mono C-H amination of arenes has been achieved using [Cp*Ir(III)Cl₂]₂ as the catalyst and 2,2,2-trichloroethoxycarbonyl (Troc) azide as an aminating reagent. The amination proceeds smoothly with a variety of arylcarbonyl compounds, including alkyl and vinyl arylketones, secondary and tertiary aryl amides, and acetyl indoles. The resulting ortho-TrocNH arylcarbonyl compounds are easily transformed to the corresponding free arylamines, aryl carbamates, or aryl ureas. Taking advantage of the electrophilic nature of both Troc and carbonyl groups in ortho-TrocNH arylcarbonyl compounds, the subsequent cyclization with dinucleophilic reagents has also been demonstrated. This provides an efficient strategy for the construction of aryl-fused N-heterocycles.