Jairus L. Lamola

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.

Abisola O. Egbedina, Jairus L. Lamola, Mina Shawky Adly, and Stephen O. Ojwach introduce the RSC Advances Young African Researchers collection.

The use of Pd‐catalysts based on biaryl phosphacycles allowed facile Suzuki‐Miyaura couplings of a wide range of deactivated, sterically hindered, and heteroaryl chloride substrates with aryl boronic acids. Notably, the strongly electron‐deficient and sufficiently hindered biaryl phosphacycle ligand 7 consistently demonstrated effective performance.

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.

Electronic and steric properties of the newly developed biaryl phosphacycles were quantified from various experimental and theoretical methods. These include user-friendly and rapid packages such as Solid-G, SambVca, and FindConeAngle for the unique steric parameterisation studies of phospho-selenides. Electronic descriptors derived from the ³¹P–⁷⁷Se coupling constants (¹J_P–Se), C–O stretching frequency (ν_CO), computed bond enthalpies (ΔE), and molecular electrostatic potentials (V_min) exhibited moderate to good correlations.

Efficient palladium catalyst systems based on the combination of bench stable biaryl phosphacycles and Pd(OAc)₂ are described for Suzuki-Miyaura cross-coupling reactions of aryl bromides and chlorides. Notably, the electronically and sterically diametric biaryl phosphacycles allowed facile coupling of sterically hindered and heterocyclic substrates. Graphical Abstract