N-Methylpyrrolidone Hydroperoxide/Cs2CO3as an Excellent Reagent System for the Hydroxy-Directed Diastereoselective Epoxidation of Electron-Deficient Olefins

Enantioseparation via Chiral Supramolecular Gels Comprising Ambidextrous Gelators Based on β-Peptide-type Primary Amines

While β-peptides have been paid attention due to their diverse secondary structures, their application to the design of low-molecular-weight gelators (LMWGs) is less explored. In this work, chiral cyclic β-amino acid-based β-peptides were developed as ambidextrous LMWGs, wherein multiple hydrogen bonds between the amide moieties led to high gelation ability. Their molecular assembly was elucidated using spectroscopies, microscopy, and X-ray analysis. Further, the supramolecular gel was used as a platform for the enantioselective extraction of (S)-naproxen from its racemate under optimized conditions. These findings have expanded the utility of β-peptides and shown the potential of supramolecular gels as a distinct dynamic medium for enantiomer separation.

Green Oxidation of Heterocyclic Ketones with Oxone in Water

The recently reported efficient conversion of cyclic ketones to lactones by Oxone in neutral buffered water is extended to heterocyclic ketones, namely, cyclic N-Boc azaketones and oxoethers with the aim of obtaining N-protected azalactones and their analogues with oxygen in place of nitrogen. N-Boc-4-piperidinone and all the cyclic oxoethers were successfully oxidized to lactones, while the azacyclic ketones with nitrogen α-positioned to carbonyl were univocally transformed into N-Boc-ω-amino acids and N-Boc-N-formyl-ω-amino acids operating in alkaline water and DMF, respectively.

Stereoselective Z-halosulfonylation of terminal alkynes using sulfonohydrazides and CuX (X = Cl, Br, I)

The unconventional Z-selective halosulfonylation of terminal alkynes has been achieved by using CuX (X = Cl, Br, I)/sulfonohydrazides at rt, providing a practical and new route for the synthesis of diverse halogenated vinyl sulfones.