Trialkylammonium (most notably N,N,N-trimethylanilinium) salts are known to display dual reactivity through both the aryl group and the N-methyl groups. These salts have thus been widely applied in cross-coupling, aryl...

The research presented here reports the surprising observation that adding glucose and other carbohydrate osmolytes to the polar phase of water-containing reverse micelles causes the particles to shrink. This apparent change in reverse micelle size is attributed to two factors: an increase in the surface area per surfactant molecule induced by the presence of carbohydrate and changes in the particle shape eccentricity. The studies reported here not only focus on glucose but also explore other carbohydrate osmolytes, specifically ethylene glycol, glycerol, erythritol, xylitol, sorbitol, myo-inositol, and trehalose, in the nanoconfined environments of reverse micelles. Through two-dimensional proton nuclear Overhauser enhancement nuclear magnetic resonance spectroscopy, the osmolytes were determined to reside solvated in the aqueous interior of the reverse micelles. This paper reports the loading limit of carbohydrates into AOT [sodium bis­(2-ethylhexyl)­sulfosuccinate] reverse micelles, demonstrates the location of the carbohydrates in the reverse micelles, and shows an unexpected effect where the carbohydrates add to the reverse micelle volume without causing an apparent increase in the reverse micelle diameter.

<i>N,N,N</i>-trimethylanilinium salts are known to display dual reactivity through both the aryl group and the <i>N</i>-methyl groups. These salts have thus been widely applied in cross-coupling, aryl etherification, fluorine radiolabelling, phase-transfer catalysis, supramolecular recognition, polymer design, and (more recently) methylation. However, their application as electrophilic methylating reagents remains somewhat underexplored, and an understanding of their arylation versus methylation reactivities is lacking. This study presents a mechanistic degradation analysis of <i>N,N,N</i>-trimethylanilinium salts and highlights the implications for synthetic applications of this important class of salts. Kinetic degradation studies, in both solid state and solution phases, have delivered insights into the physical and chemical parameters affecting anilinium salt stability. ¹H NMR kinetic analysis of salt degradation has evidenced thermal degradation to methyl iodide and the parent aniline, consistent with a closed-shell S_N2-centred degradative pathway, and methyl iodide being the key reactive species in applied methylation procedures. Furthermore, the effect of halide and non-nucleophilic counterions on salt degradation has been investigated, along with deuterium isotope and solvent effects. Finally, new mechanistic insights have enabled the investigation of the use of trimethylanilinium salts in O-methylation and in improved cross-coupling strategies.

Safety signage is an important part of a chemical laboratory. At the University of Strathclyde, Scotland, a researcher had been carrying out work with β-lactam compounds similar to penicillin and, as this compound class represents well-known allergens, signs were placed on entrances to the laboratory and adjoining corridor to warn visitors of the hazard about the ongoing use of potent allergens in the area. 1,2 When the research was successfully concluded, the associated chemicals were safely disposed of through collaboration with trained environmental health and safety (EH&S) technical staff. However, the hazard warning signs were not taken down at the same time. A maintenance worker was later carrying out routine safety checks of eye-wash stations in the chemistry building wherein the β-lactam work had been conducted. The worker had a penicillin allergy, so upon seeing the warning signs, decided not to enter the corridor to carry out the essential eye-wash checks needed for that particular laboratory. Fortunately, the maintenance worker reported that they could not enter the floor to the departmental safety manager. It was then promptly identified that the signs were no longer relevant and could be safely removed from view. The eye-wash checks were carried out. Had the maintenance worker not reported the presence of the allergy warning posters, the eye-wash station could have gone unchecked, leading to potentially severe consequences in an emergency situation in which the eye-wash was needed. This incident highlights the importance of managing safety considerations during a period of operational change in research. 3 Risks often occur from a lack of displaying appropriate hazard warnings. In this case, it was the out-of-date signage not removed that that led to a near miss.