On-Demand Release of Secondary Amine Bases for the Activation of Catalysts and Crosslinkers

We demonstrate that the species present in the equilibrium of DCv ureas can be employed in reaction cascades and as triggered organocatalysts. Easily controllable stimuli like heat or addition of water shift the equilibrium towards isocyanate and free base which can function as an in situ released reagent, both catalytically and in an equimolar fashion in different reactions. While applying heat to the system leads to a reversible liberation of amine base, addition of water makes this release irreversible. We demonstrate this application of DCv ureas with two examples via ¹H-NMR spectroscopy. Firstly, we use the liberated base to activate a protected organocatalyst for acylhydrazone formation. Secondly, this base can be employed to trigger the release of nitrile-N-oxides from chlorooximes, which can react with 4-arm PEG-thiols to form a thiohydroximate polymer gel. These findings show the utility of DCv hindered ureas beyond their application in self-healing.

On-Demand Release of Secondary Amine Bases for the Activation of Catalysts and Crosslinkers

We demonstrate that the species present in the equilibrium of DCv ureas can be employed in reaction cascades and as triggered organocatalysts. Easily controllable stimuli like heat or addition of water shift the equilibrium towards isocyanate and free base which can function as an in situ released reagent, both catalytically and in an equimolar fashion in different reactions. While applying heat to the system leads to a reversible liberation of amine base, addition of water makes this release irreversible. We demonstrate this application of DCv ureas with two examples via ¹H-NMR spectroscopy. Firstly, we use the liberated base to activate a protected organocatalyst for acylhydrazone formation. Secondly, this base can be employed to trigger the release of nitrile-N-oxides from chlorooximes, which can react with 4-arm PEG-thiols to form a thiohydroximate polymer gel. These findings show the utility of DCv hindered ureas beyond their application in self-healing.

(Hexamethylbenzene)Ru catalysts for the Aldehyde-Water Shift reaction

The Aldehyde-Water Shift (AWS) reaction uses H2O as a benign oxidant to convert aldehydes to carboxylic acids, producing H2, a valuable reagent and fuel, as its sole byproduct.

Transient seizure-induced sodium increase camouflaging a symptomatic hyponatremia

Hyponatremia is the most commonly observed electrolyte disturbance in clinical medicine. Occasionally the initial presentation of a patient with a symptomatic hyponatremia is a seizure or coma. This life-threatening complication needs early diagnosis and immediate treatment. Here, we report a case of a 27-year-old man who presented with an epileptic seizure, lactate acidosis and sulcal effacement on CT in which a transient sodium increase masked a clinically relevant hyponatremia thereby delaying diagnosis. This phenomenon is caused by an extracellular water shift and can occur when blood analysis is performed shortly after vigorous exercise or a seizure. This case provides awareness for a less well-known cause of plasma sodium increase and offers recommendations to prevent misinterpretation and help clinicians in decision making.