Streptazone A and abikoviromycin are alkaloids that both feature an unusual arrangement of reactive functionalities within a compact tricyclic ring system. Here, we report highly concise asymmetric synthesis natural products. The route first constructs another family member, streptazone B1, using rhodium-catalyzed distal selective allene-ynamide Pauson–Khand reaction. regio- enantioselective ep...

Selective transformations in carbohydrate chemistry will be illustrated with examples chosen from three distinct areas: 1. Phase transfer reactions are useful in obtaining partially substituted carbohydrate intermediates. The substitution patterns frequently are quite different to those obtained in homogeneous phase. 2. Various reagent systems have been developed for the conversion of hyd roxy ...

Abstract Metal-catalyzed [2+2+2] cycloaddition is a powerful tool that allows rapid construction of functionalized 6-membered carbo- and heterocycles in single step through an atom-economical process with high functional group tolerance. The reaction usually regio- chemoselective although selectivity issues can still be challenging for intermolecular reactions involving the cross-[2+2+2] two or...

Abstract: Chemoselective ligation reactions are highly efficient and specific covalent bond forming reactions capable of proceeding within a physiological environment. Chemoselective ligations offer exquisite specificity, similar to enzymatic reactions, but with the significant advantage of accessing a much broader range of coupling partners. Thus, even among a multitude of reactive functional ...

For the synthesis of m-sulfamoylbenzamide analogues, small molecules which are known for their bioactivity, a chemoselective procedure has been developed starting from m-(chlorosulfonyl)benzoyl chloride. Although a chemoselective process in batch was already reported, a continuous-flow process reveals an increased selectivity at higher temperatures and without catalysts. In total, 15 analogues ...

The first ultrasound-promoted multicomponent synthesis of pyridazinones and phthalazinones from arenes, cyclic anhydrides and ArNHNH(2) in the presence of an efficient recyclable catalyst, [bmim]Br/AlCl(3), in high yield and short reaction time is reported.