To produce the antibiotic Microcin B17, four Cys and four Ser residues are converted into four thiazoles and four oxazoles by the three subunit Microcin B17 synthetase. High-resolution mass spectrometry (MS) was used to monitor the kinetics of posttranslational heterocyclic ring formation (-20 Da per ring) and demonstrated the accumulation of all intermediates, from one to seven rings, indicati...

(E)-3-Arylidene-4-diazopyrrolidine-2,5-diones previously shown to yield two products in reactions with tetrahydrofuran mediated by rhodium carbenes—tetrahydrofur-2-yl-substituted product of C-H insertion and spirocyclic formal C-O insertion. Accidentally, it was noted that the ratio depends on catalyst loading, phenomenon investigated detail. It found be preparative significance: solely changin...

Herein, we present recent advances in the application of metal nanoparticles selective hydrogenation C–C double bonds. The review focuses on reduction methods alkenes, arenes, and aromatic heterocycles, which were classified according to transition metals used as catalysts. majority described systems concern direct hydrogenation, is particular importance industrial processes. Nonetheless, inter...

The Nenitzescu reaction is a condensation between an enamine and quinone, which can give rise to wide variety of products depending on the nature starting material conditions. most commonly observed are 5-hydroxyindoles 5-hydroxybenzofurans. Both classes interest since they known possess promising bioactivities. Despite high chemodivergency for this reaction, it remains interesting synthetic st...

Deuterium-labeled nicotinamide cofactors such as [4-2H]-NADH can be used mechanistic probes in biological redox processes and offer a route to the synthesis of selectively [2H] labeled chemicals via biocatalytic reductive deuteration. Atom-efficient routes formation recycling are therefore highly desirable but require careful design order alleviate requirement for [2H]-labeled reducing agents. ...

The sulfated polyborate catalyzed an efficient and chemoselective N-tert-butyloxycarbonylation of amines under ultrasonic irradiation is developed. A broad substrate scope has been demonstrated for N-Boc protection various primary/secondary amines. It allows converting several aliphatic/aryl/heteroaryl amines, amino alcohol, aminoester, chiral to their N-Boc-protected derivatives solvent-free c...

Peptide modification has emerged as an important topic in the academic community and pharmaceutical industry. However, they are primarily focused on diversification of amines, thiols, alcohols. Direct chemoselective acid residues peptides is relatively underdeveloped. In this context, we report a novel efficient method for direct functionalization peptides. By using ynamides reaction partners, ...