10 research outputs found
Synthesis of Chiral NADH Analog Based on Proline Template Including Thiourea and Nicotinic Acid Moieties
La nozione di gioco linguistico tra "paradigma" e Lebensform. Wittgenstein, Kuhn, Hadot
Il saggio affronta l'ambivalenza del temine gioco linguistico sia sul piano della Physis - facendo riferimento alla proposta epistemologica kuhniana, con particolare attenzione al costrutto di paradigma - sia sul piano dell'ethos facendo particolare riferimento al concetto di forma di vita, da cui esso trae origine proprio nell'evoluzione del pensiero wittgensteiniano. In questa parte del lavoro trova spazio anche la lettura di Hadot che proprio grazie all'approfondimento delle proposta del secondo Wittgenstein ricostruisce l'idea del linguaggio comparativo di cui facevano largamente uso gli antichi, nel loro considerare la filosofia prima di tutta come una prassi quotidiana
Enantioselective, Organocatalytic Reduction of Ketones using Bifunctional Thiourea-Amine Catalysts
Unexpected catalysis: aprotic pyridinium ions as active and recyclable Brønsted acid catalysts in protic media
Dynamic multi-component covalent assembly for the reversible binding of secondary alcohols and chirality sensing
Reversible covalent bonding is often employed for the creation of novel supramolecular structures, multi-component assemblies, and sensing ensembles. In spite of remarkable success of dynamic covalent systems, the reversible binding of a mono-alcohol with high strength is challenging. Here we show that a strategy of carbonyl activation and hemiaminal ether stabilization can be embodied in a four-component reversible assembly that creates a tetradentate ligand and incorporates secondary alcohols with exceptionally high affinity. Evidence is presented that the intermediate leading to binding and exchange of alcohols is an iminium ion. Further, to demonstrate the use of this assembly process we explored chirality sensing and enantiomeric excess determinations. An induced twist in the ligand by a chiral mono-ol results in large Cotton effects in the circular dichroism spectra indicative of the alcohol’s handedness. The strategy revealed in this study should prove broadly applicable for the incorporation of alcohols into supramolecular architecture construction