Paseka T. Moshapo

Imides have a vast presence in pharmaceuticals and natural products, and their synthesis generally relies on the utility of the disagreeable strong oxidants. Herein, we report an oxidant‐free protocol that combines N ‐(acyloxy)‐tetrachlorophthalimides, derived from abundant carboxylic acids, and acid anhydrides with isothiouronium salts. Crucial to this protocol is the provision of access to sulfur‐substituted imides, which were previously limited to sulfur‐ β ‐allyl‐substituted imides and the use of undesirable free thiols. To this end, this developed protocol provides a scalable and functional group‐tolerant reactivity with product yields of up to 96% under mild reaction conditions.

Amides are important structures with relevance in biology, material science, and synthetic chemistry. Their photochemical synthesis via aminolysis of acetyldisulfides relies on a reductive regime of thioacids using transition metal-based photocatalysts and organic dyes. Here, we report that readily available tetrachlorophthalimide can serve as an organocatalytic acceptor to thioacids for the electron donor–acceptor (EDA) photoactivation, thereby generating the desired thioacyl radicals suitable for dimerization and, subsequently, amidation via aminolysis. The usefulness of this EDA platform enabled us to develop and demonstrate a mechanistically distinct synthesis of sterically and electronically diverse amides using thioacids as acyl sources, with isolated yields of up to 97%. Furthermore, the reactions proved to be efficient and easy to operate as they could be conducted under an open-air atmosphere, eliminating the need to create a rigorous inert atmosphere. Notably, the gram-scale synthesis of paracetamol was achieved using the developed photochemical transformation.

An efficient three-component one-pot synthesis of S -substituted N -acyl urea derivatives via alkylation and carbamoylation of thiourea is reported.

Aluminium triflate, a relatively new addition to the family of metal triflates, showcases a distinctive reactivity profile that sets it apart from traditional Lewis acids such as aluminium chloride (AlCl3), tin (IV) chloride (SnCl4), and boron trifluoride (BF3). Its unique properties make it an attractive candidate for various catalytic applications. Notably, aluminium triflate can be easily prepared and utilised at low catalyst loadings, enhancing its efficiency and cost-effectiveness. Furthermore, its recyclability contributes to sustainable practices, aligning perfectly with the principles of green chemistry. The solubility and stability of aluminium triflate in aqueous media further enhance its appeal, as these characteristics allow for more environmentally friendly reaction conditions. Compared to other catalytic systems, Al(OTf)3 exhibits consistently superior performance, particularly in terms of selectivity and turnover frequency. This superior reactivity makes it a powerful tool in organic synthesis, enabling chemists to achieve desired transformations with greater precision and efficiency. In this comprehensive review, we explore the significant advancements in the application of aluminium triflate as a catalyst in organic transformations from 1985 to 2024. We highlight key studies that demonstrate its versatility across various reaction types, including the formation of carbon-carbon and carbon-heteroatom bonds. This critical analysis of advancements in this field aims to provide insights into the future potential of aluminium triflate in organic synthesis and its role in advancing sustainable chemistry practices.

Tuberculosis (TB) continues to be a threat to global health stability. Pyrimidine carboxamides have demonstrated potent anti-tubercular properties against clinical Mycobacterium tuberculosis, the causative agent of TB. Herein, we report a follow-up study on the synthesis of pyrimidine carboxamide molecular analogues and their anti-TB evaluation. In total, a library consisting of 37 new compounds is reported. Seven compounds (7b, 7d, 7m, 7p, 7q, 7aa, and 7ah) demonstrated excellent in vitro activities with MIC₉₀ values below 1.00 µM. Apart from compound 7ah, compounds with improved aqueous solubility properties had lower anti-TB potency. Preliminary mode of action studies using bioluminescence assays indicate that the active compounds do not affect the integrity of mycobacterial DNA or the cell wall. The active compounds were also found to be bactericidal against replicating H37Rv Mtb strain.

Tuberculosis (TB) continues to be a threat to global health stability. Pyrimidine carboxamides have demonstrated potent anti-tubercular properties against clinical Mycobacterium tuberculosis, the causative agent of TB. Herein, we report a follow-up study on the synthesis of pyrimidine carboxamide molecular analogues and their anti-TB evaluation. In total, a library consisting of 37 new compounds is reported. Seven compounds (7b, 7d, 7m, 7p, 7q, 7aa, and 7ah) demonstrated excellent in vitro activities with MIC₉₀ values below 1.00 µM. Apart from compound 7ah, compounds with improved aqueous solubility properties had lower anti-TB potency. Preliminary mode of action studies using bioluminescence assays indicate that the active compounds do not affect the integrity of mycobacterial DNA or the cell wall. The active compounds were also found to be bactericidal against replicating H37Rv Mtb strain.

The use of catalysts derived from Pd ₂ (dba) ₃ and phosphatrioxa‐adamantane framework (Cg) has been demonstrated to facilitate the effective alpha( α) ‐arylation of ketones using a diverse array of aryl halides under mild reaction conditions (40 °C–80 °C). The evaluation of phosphines with dissimilar stereoelectronic properties revealed the pivotal role of fine‐tuning the ligand's steric bulk. In particular, catalysts based on the Cg‐biphenyl ligand ( 1 ) proved efficient for facile α ‐arylation of electronically and sterically diverse aryl bromides and chlorides.

Amide functional groups are a structural feature in a vast array of beneficial organic molecules. This has resulted in a surge in new methodologies developed to enable access to this functional group using a broad range of coupling partners. Herein, we report a palladium-catalysed reductive aminocarbonylation of aryl bromides and iodides with nitroarenes to afford the respective amide products. The developed protocol employs Mo(CO)₆ as a carbonyl source and a combination of Zn and TMSCl as co-reducing agents. For most substrates, the anticipated amide products were obtained in modest to high amide product yields. Received: 17 August 2022 Accepted: 19 August 2022 Article published online: 22 September 2022 © 2022. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/) Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany