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By using water as the hydrogen source, an eco-friendly and practical protocol for the synthesis of Z-vinyl thiocyanates through ultrasound-promoted Brønsted acid ionic liquid-catalyzed hydrothiocyanation of activated alkynes under minimal solvent conditions has been developed. This process effectively avoids the use of organic solvents, metal catalysts and harsh reaction conditions. This reaction shows attractive characteristics such as operational simplicity, broad substrate scope with good to excellent yields, ease of scale-up and high energy efficiency and recyclable and reusable catalysts. [ABSTRACT FROM AUTHOR]

We describe an eco-friendly, practical and operationally simple procedure for the bis(methoxypropyl) ether-promoted oxidation of aromatic alcohols into aromatic carboxylic acids and aromatic ketones with atmospheric dioxygen as the sole oxidant. This chemical process is clean with high conversion and good selectivity, and an external initiator, catalyst, additive and base are not required. The virtue of this reaction is highlighted by its easily available and economical raw materials and excellent functional group tolerance (acid-, base- and oxidant-labile groups). [ABSTRACT FROM AUTHOR]

A highly efficient way for the direct (trans)esterification of acyl acids (esters) and alcohols in a strict 1 : 1 ratio using a zirconocene complex (1, 1 mol%), a strong Lewis acid of good water tolerance, as a catalyst under solvent-free conditions has been developed. A wide range of acid and alcohol (esters) substrates undergo (trans)esterification to produce carboxylic ester motifs in moderate to good or excellent yields with good functional tolerance, such as that towards C–Br as well as C=C and C≡C bonds. And complex 1 can be recycled six times without showing a significant decline in catalytic efficiency. It was demonstrated that cyclandelate, which is used to treat high blood pressure as well as heart and blood-vessel diseases, can be directly synthesized on a gram scale with 81% yield (6.70 g) using complex 1. [ABSTRACT FROM AUTHOR]

A Ni-catalyzed oxidative C–H/C–H cross-dehydrogenative coupling (CDC) reaction was developed for constructing various highly functionalized alkyl (aryl)-substituted thiophenes. This method employs thiophenes and aliphatic (aromatic) amides that contain an 8-aminoquinoline as a removable directing group in the presence of a silver oxidant. The approach enables the facile one-step synthesis of substituted thiophenes with high functional group compatibility via double C–H bond cleavage without affecting C–Br and C–I bonds. DFT calculations verify the importance of KH2PO4 as an additive for promoting C–H bond cleavage and support the involvement of a Ni(iii) species in the reaction. [ABSTRACT FROM AUTHOR]

A simple and facile method is described for the morphology-controlled synthesis of bimetallic Au–Pd alloyed nanochain networks (NNCs) that show high catalytic performance for the Ullmann intermolecular homocoupling of aromatic or alkyl halides (X = I, Br, Cl) in aqueous media and can be reused at least five times, which can also be applied to intramolecular homocoupling. [ABSTRACT FROM AUTHOR]

In the direct Mannich reaction and synthesis of α,β-unsaturated ketones, the use of organobismuth complexes as catalysts leads to high diastereoselectivity and products of single transconformation. In this paper, we illustrate the relationship between structure and catalytic activity as well as diastereoselectivity of organobismuth complexes having a 5,6,7,12-tetrahydrodibenz [c,f][1,5]thiobismocine framework as well as bearing a butterfly-shaped sulfur-bridged ligand and tunable anions. With the exposed bismuth center acting as a Lewis acid site and the uncoordinated lone pair electrons of sulfur as a Lewis base site, the cationic organobismuth complexes work as bifunctional Lewis acid/base catalysts. Due to the steric influence of the butterfly-shaped structure and synergistic effect of Lewis acid and Lewis base centers, the complexes can direct substrate attack in organic synthesis. By adjusting the electron-withdrawing ability of the counter anions, the S–Bi bond strength can be regulated, leading to a significant change in Lewis acidity and Lewis basicity as well as catalytic activity. Through synergistic modulation of the above effects, one can control the diastereoselectivity of the organobismuth complexes for the generation of a single diastereoisomer. [ABSTRACT FROM AUTHOR]

The catalyst system that comprises an air-stable bifunctional Lewis acidic/basic organobismuth complex and [Bmim]BF4is highly efficient in the cross-condensation of aldehydes with ketones. Through switching the reaction from homogeneous to heterogeneous, the system shows facile separation ability and facile reusability. [ABSTRACT FROM AUTHOR]

An air-stable cationic organobismuth complex was successfully synthesized and found to show high catalytic efficiency in the direct diastereoselective Mannich reaction in water. [ABSTRACT FROM AUTHOR]