Electrosynthesis of 2-Substituted Benzoxazoles via Intramolecular Shono-Type Oxidative Coupling of Glycine Derivatives

Abstract

Herein, an atom-economical and eco-friendly electrochemical oxidation/cyclization of glycine derivatives through intramolecular Shono-type oxidative coupling is disclosed, leading to a variety of 2-substituted benzoxazoles in 51–85% yields. This oxidative cyclization proceeded in transition metal- and oxidant-free conditions and generated H2 as only a byproduct. Additionally, gram-scale reactions and a broad substrate scope demonstrated the synthetic usefulness of this protocol.

Metabarcoding analysis of the bacterial and fungal communities during the maturation of preparation 500, used in biodynamic agriculture, suggests a rational link between horn and manure

“…While there are no prior literature reports on horn manure culture-independent metabarcoding, some indirect comparisons can be made. As concerns the starting cow manure, its bacterial community composition is in line with the profile known for bovine faecal material, featuring a majority of Firmicutes and a variable amount of Bacteroidetes as main taxa [22,23]. A major event observed in the early stage of maturation of manure in our study is the transient 'bloom' of the genus Acinetobacter (Proteobacteria) at 40 days (Supplementary Fig.…”

The Oxidation of Organo‐Boron Compounds Using Electrochemically Generated Peroxodicarbonate

“…In general, electrochemistry can be considered a favorable alternative to conventional chemical processes as it is inherently safe and produces less waste [19–23] . It is already established in numerous applications such as dehydrogenative coupling reactions [34–36] and construction of heterocycles such as indazolinones, [37] pyrazoles/pyrazolines, [38] pyrazolidine‐3,5‐diones, [39,40] and benzoxazoles [39,41–43] …”

“…[19][20][21][22][23] It is already established in numerous applications such as dehydrogenative coupling reactions [34][35][36] and construction of heterocycles such as indazolinones, [37] pyrazoles/pyrazolines, [38] pyrazolidine-3,5-diones, [39,40] and benzoxazoles. [39,[41][42][43] (Para)periodate has recently been established as a highperformance platform oxidizer which can be generated at a boron-doped diamond anode. [44] It has been utilized in the contaminant-free syntheses of drug molecules such as levetiracetam and has great potential in pharmaceutical applications and direct access to elaborated building blocks.…”