The ruthenium-catalyzed hydroamidation of terminal alkynes has evolved to become a broadly applicable tool for the synthesis of enamides and enimides. Depending on the catalyst system employed, the reaction leads chemo-, regio-, and stereoselectively to a single diastereoisomer. Herein, we present a comprehensive mechanistic study of the ruthenium-catalyzed hydroamidation of terminal alkynes, which includes deuterium-labeling, in situ IR, in situ NMR, and in situ ESI-MS experiments complemented by computational studies. The results support the involvement of ruthenium-hydride and ruthenium-vinylidene species as the key intermediates. They are best explained by a reaction pathway that consists of an oxidative addition of the amide, followed by insertion of a π-coordinated alkyne into a ruthenium-hydride bond, rearrangement to a vinylidene species, nucleophilic attack of the amide, and finally reductive elimination of the product.

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A new series of coumarin and benzofuran derivatives were synthesized as potential non-nucleoside reverse transcriptase inhibitors (NNRTIs) by reacting, separately, 4-bromomethylcoumarins, their sulphonyl chlorides, and ethyl 3-(bromomethyl)-6-methoxy-1-benzofuran-2-carboxylate with different imidazoles and their benzo analogs. The antiviral (HIV-1, HIV-2) properties of the newly synthesized compounds were investigated in vitro and all compounds were found to be inactive, except 10 which showed inhibition of HIV-2 with EC50 > 0.51 μgmL−1. The in vitro cytotoxicity of 17 and 19 was assayed against a panel of tumor cell lines consisting of CD4 human T-cells.

Extremely small, monodisperse, and spheric maghemite (γ-Fe2O3, 2–3 nm) and manganese (4–7 nm), cobalt (3–5 nm), and zinc ferrite (5–7 nm) nanocrystals are directly accessible on a large scale starting from inexpensive metal powders and octanoic acid by thermolysis in a high-boiling solvent. Bigger particle size is obtainable by prolonged reaction time according to the Ostwald ripening principle. The superparamagnetic nanocrystals and their assembly have been characterized by transmission electron microscopy, powder X-ray diffraction, Mössbauer spectroscopy, magnetic measurements, and energy-dispersive X-ray spectroscopy.

A catalyst system generated in situ from bis(2-methallyl)-cycloocta-1,5-diene-ruthenium(II) and a phosphine was found to efficiently catalyze the addition of thioamides to terminal alkynes with exclusive formation of the anti-Markovnikov thioenamide products. The stereoselectivity of the addition is usually high and controlled by the choice of the phosphine ligand, whereas the (E)-isomers are predominantly formed in the presence of tri(n-octyl)phosphine, the use of bis(dicyclohexylphosphino)methane preferentially leads to the formation of the (Z)-configured thioenamides.

Cross-coupling reactions furnishing carbon–carbon (C–C) bond is one of the most challenging tasks in organic syntheses. The early developed reaction protocols by Negishi, Heck, Kumada, Sonogashira, Stille, Suzuki, and Hiyama, utilizing palladium or its salts as catalysis have, for decades, attracted and inspired researchers affiliated with academia and industry. Tremendous efforts have been paid to develop and achieve more sustainable reaction conditions, such as the reduction in energy consumption by applying the microwave irradiation technique. Chemical reactions under controlled microwave conditions dramatically reduce the reaction time and therefore resulting in increase in the yield of the desired product by minimizing the formation of side products. In this review, we mainly focus on the recent advances and applications of palladium catalyzed cross-coupling carbon–carbon bond formation under microwave technology.

A series of four donor–acceptor conjugated copolymers P1–P4 with linear and branched side chains based on a ladder-type indacenodithiazole (IDTz) moiety containing an electron-deficient thiazole unit are copolymerized with di-2-thienyl-2,1,3-benzothiadiazole (DTBT) and 4,7-di­(thien-2-yl)-5,6-difluoro-2,1,3-benzothiadiazole (DTBTff) as building blocks. Their optical, electrochemical, and thermal properties and charge transport behavior in organic field-effect transistors (OFETs) are studied. All copolymers exhibit nearly identical features in solution with good solubility. In the solid state, P1 does not exhibit a significant shift, while P3 shows a 27 nm red shift, thus illustrating the influence of the side chain. In the case of copolymers P1 and P2 having linear side chains, there is a clear effect of fluorination on the film morphology, while it is less pronounced in the case of polymers P3 and P4 having branched side chains. All copolymers P1–P4 have similar highest occupied molecular orbitals regardless of fluorination, while fluorinated polymers P2 and P4 result in an increase in the lowest unoccupied molecular orbital. In addition, density functional theory calculations reveal that the energy levels of IDTz are down-shifted in comparison to its IDT counterpart containing an electron-rich thiophene unit. OFETs based on all copolymers exhibit ambipolar behavior; among the four copolymers, P2 having a linear dodecyl side chain exhibits remarkable transport properties with saturated hole mobility as high as 0.87 cm2 V–1 s–1, while P3 exhibits the highest electron mobility of up to 0.50 cm2 V–1 s–1. Our results set an interesting path to further utilize the electron-deficient thiazole block in semiconducting materials.