N-Carboxyanhydrides directly from amino acids and carbon dioxide and their tandem reactions to therapeutic alkaloids

Abstract

We report on the preparation of synthetically versatile N-carboxyanhydrides (NCAs) directly from amino acids and CO2 using n-propylphosphonic anhydride. Most of the NCAs were isolated with >95% purity after simple...

Recent advances of tryptanthrin and its derivatives as potential anticancer agents

“…88 Fourthly, most of the tryptanthrin metal complexes can enhance the already strong anticancer activity of free tryptanthrin or its derivatives, due to the synergetic effect of coordination. 87,[89][90][91] In addition, the preparation and structure of some tryptanthrin derivatives are reported, but their anticancer activities are not investigated, [132][133][134][135][136][137][138][139][140][141][142][143] in particular, some literature data on the anticancer tryptanthrin derivatives are not always homogeneous, such as different incubation times used for the test of cytotoxicity, different units of IC 50 , no IC 50 values in many tryptanthrin derivatives, and different types of structural modes, so the cytotoxicity of most tryptanthrin derivatives might be not invariably comparable.…”

Highly Selective Electrochemical Baeyer–Villiger Oxidation through Oxygen Atom Transfer from Water

“…In the pursuit of developing sustainable alternatives for catalysis, − oxygen atom transfer (OAT) reactions are of great importance for chemical synthesis . Traditionally, this class of reactions relies on strong oxidants such as peroxyacids, peroxides, or molecular oxygen (O 2 ), which are often difficult to handle. , As a result, it presents a challenge for large-scale implementations, such as the preparation of monomers for polymeric materials. , Recent advances have inspired researchers to address these challenges by exploiting in situ generated oxidants. − Promising results have been obtained by electrochemically (or photoelectrochemically) oxidizing H 2 O to produce intermediates, including oxo species, , peroxo species, hydroperoxo species, , hydroxyl radicals, and reactive atomic surface oxygen species, which can be directly utilized for OAT.…”

Heterometallic YbCo–Organic Framework for Efficiently Catalyzing Cycloaddition of CO2 with Epoxides and Knoevenagel Condensation

“…Metal–organic frameworks (MOFs), as a kind of porous material self-assembled from metal centers and organic ligands through coordination bonds, have been studied extensively in a wide range of applications such as gas adsorption–separation–storage, ion fluorescence probe, magnetism, targeted drug delivery system, and heterogeneous catalysis, owing to their high specific surface area, suitable size distribution, flexibility, and good thermal stability. − However, the research on MOF-based catalytic applications lags behind other subjects, which may be due to the relatively low chemical stability, thermal decomposition, and hydrolysis. Recently, heterogeneous catalysis of lanthanide-based metal–organic frameworks (Ln-MOFs) has been widely studied due to their unique properties such as extremely high thermal stability, chemical stability in organic solvents, excellent selective catalysis, easy recovery, and reusability. − Over the years, although the synthetic strategies of crystal engineering have gradually become mature, reported microporous Ln-MOFs compared to MOFs based on transition metals are relatively rare, which should be attributed to the fact that the excessive coordination number and difficulty in controlling the coordination geometry often lead to indeterminate solid powder or interspersed multidimensional structures. However, this situation has gradually changed in recent years because the successful design of functional ligands leads to a number of microporous Ln-MOFs with unique thaumaturgic topologies, which have a lot of potential for scientific and industrial applications.…”