Thiocyanation and 2-Amino-1,3-thiazole Formation in Water Using Recoverable and Reusable Glycosylated Resorcin[4]arene Cavitands

A family of three spatially directional resorcin[4]arene cavitand glycoconjugates (RCGs) have been applied as efficient recoverable and reusable inverse phase transfer catalysts for eco- and environmentally friendly thiocyanation and 2-amino-1,3-thiazole formation reactions in water. The results show that RCGs (1 mol %) were capable of hosting and catalyzing various water-insoluble bromo/thiocyanato substrates in water without the use of any co-organic solvents. The recoverability and reusability of RCG catalytic systems, that is, RCG1 and RCG3, were also examined upon a simple extraction of the desired products using DCM or ethyl acetate, followed by subjecting the recovered aqueous solution containing the RCG catalysts to the next reaction cycles.

Acetone: a solvent or a reagent depending on the addition order in SET-LRP

The importance of reagent order in biphasic SET-LRP in acetone/water mixtures is shown.

Highly Efficient Heterogeneous Copper-Catalysed Coupling of Oxime Acetates with Isothiocyanates Leading to 2-Aminothiazoles

The heterogeneous coupling reaction of oxime acetates with isothiocyanates was achieved at 110 °C in toluene in air in the presence of a bidentate nitrogen-functionalised MCM-41-immobilised copper(I) complex (MCM-41-2N-CuI) with Cs2CO3 as base to afford a variety of 2-aminothiazoles in good yields. The MCM-41-2N-CuI catalyst can be easily recovered by a simple filtration and reused at least eight times without significant loss of activity.

Copper-Catalyzed Coupling of Oxime Acetates with Isothiocyanates: A Strategy for 2-Aminothiazoles

A new strategy for 2-aminothiazoles is developed via the copper-catalyzed coupling of oxime acetates with isothiocyanates. Various 4-substituted and 4,5-disubstituted 2-aminothiazoles were formed smoothly under mild reaction conditions. This process involved copper-catalyzed N-O bond cleavage, activation of vinyl sp(2) C-H bonds, and C-S/C-N bond formations. It is noteworthy that the oxime acetates were used not only as a substrate but also as a single oxidant.