10.1016/j.tetlet.2009.11.056
The purpose of this study was to achieve mild, efficient, and selective removal of the N-tosyl group, a protecting group for primary and secondary amines, under neutral and mild conditions without the use of harmful and toxic reagents. The researchers successfully carried out the deprotection using constant current electrolysis with an undivided cell equipped with a platinum cathode and a magnesium anode, in the presence of an arene mediator, such as naphthalene or biphenyl. The process resulted in the corresponding secondary amines in good to excellent yields, demonstrating the efficiency of the method and its potential as a powerful tool for the synthesis of various nitrogen-containing organic compounds. The chemicals used in this process include N,N-disubstituted p-toluenesulfonamides, platinum, magnesium, and an arene mediator, along with a supporting electrolyte, Et4NBr, in DMF solvent.
10.1016/j.tetlet.2011.04.085
The research focuses on the synthesis of a monofunctionalized resorcin[4]arene derivative through thiomethylation using N,N-diisopropyl-2-aminoethanethiol hydrochloride and formaldehyde in methanol/acetic acid at 60°C. The introduced substituent self-includes into the cavity of the resorcin[4]arene, reducing the reactivity of the aromatic rings and inhibiting further functionalization. The study explores the reaction conditions and yields, with the optimal conditions yielding the monofunctionalized product in 68%. The 1H NMR and 13C NMR spectra provide evidence of the self-inclusion of the substituent, with the interaction being intramolecular. The stability of the self-inclusion complex is examined through competitive complexation experiments with tetraethylammonium bromide, revealing a low association constant indicative of high stability. The research concludes that the self-inclusion of the substituent plays a dominant role in controlling the selectivity of the reaction, and further studies on novel resorcin[4]arene derivatives are underway.
10.1021/jo801580g
The study, titled "Oxidative Conversion of r,r-Disubstituted Acetamides to Corresponding One-Carbon-Shorter Ketones Using Hypervalent Iodine (λ5) Reagents in Combination with Tetraethylammonium Bromide," investigates a novel method for converting R,R-disubstituted acetamides into ketones that are one carbon atom shorter. The key chemicals involved are hypervalent iodine (λ5) reagents, specifically o-iodoxybenzoic acid (IBX) and Dess-Martin periodinane (DMP), and tetraethylammonium bromide (TEAB). These reagents are used to oxidatively dehomologate R,R-disubstituted acetamides, resulting in the formation of ketones. The study establishes a mild, efficient, and general method for this transformation, with IBX and TEAB in acetonitrile at 60 °C yielding the best results. The researchers also explored the reaction mechanism, proposing that an N-bromoimine intermediate forms during the process, which subsequently hydrolyzes to produce the ketone.