Descrizione del progetto
Alogeni e calcogeni: nuovi legami non covalenti per la chimica e l’organocatalisi
I legami covalenti forti, in cui gli elettroni sono equamente condivisi da due atomi, favoriscono la formazione di molecole. I legami a idrogeno sono più deboli, con un’attrazione elettrostatica fra un dato atomo e un atomo di idrogeno legato in modo covalente a un altro atomo. Questi legami non covalenti sono importanti nella chimica supramolecolare, nella chimica organica e nell’organocatalisi. Il progetto XBCBCAT, finanziato dal Consiglio europeo della ricerca, svilupperà le prime applicazioni per due ulteriori interazioni non covalenti basate su alogeni o calcogeni, i cosiddetti legami alogeno e calcogeno. Il gruppo coinvolto nel progetto si concentrerà sui legami alogeni per il riconoscimento chirale e sui legami calcogeni per applicazioni nella sintesi organica e nell’organocatalisi. Queste applicazioni senza precedenti miglioreranno gli strumenti a disposizione dei chimici per quanto riguarda le interazioni non covalenti e la flessibilità dei requisiti dell’idrogeno.
Obiettivo
Hydrogen-bonds have found widespread use in various fields of chemistry, including supramolecular chemistry, organic chemistry, and more lately organocatalysis. Although a multitude of structurally different hydrogen-bond donors has been developed, their mode of action is in all cases necessarily based on the same interacting atom, hydrogen.
In this proposal, we aim to develop first applications for two, previously very little explored non-covalent interactions that are based on electrophilic halogen or chalcogen substituents (“halogen-bonds” and “chalcogen bonds”).
The first objective is to open the way for the use of chiral multidentate halogen-bond donors (i.e. halogen-based Lewis acids) for enantiodiscrimination. After the synthesis of suitable candidate compounds, we will apply them in the following research areas: a) the resolution of racemic mixtures by co-crystallization with chiral halogen-bond donors, and b) the use of these Lewis acids in enantioselective organocatalysis.
Within the second objective, we will strive to establish first-of-its-kind applications of chalcogen-based Lewis acids in organic synthesis and organocatalysis. In contrast to halogen-bonds, chalcogen-bonds feature two substituents on the interacting atom as well as two electrophilic axes. In the first phase of this aim, we will synthesize neutral and cationic, mono- and bidentate candidate compounds and determine their association constants with a variety of Lewis bases. Based on this date, we subsequently seek to use these novel Lewis acids as activators or catalysts in organic transformations.
We anticipate that the realization of these applications, all of which are unprecedented, will be a crucial first step towards establishing further non-covalent interactions as useful tools in chiral recognition and chemical synthesis. In the long-term, we foresee these little-explored interactions becoming powerful complements to the ubiquitous hydrogen-bonds.
Campo scientifico
Programma(i)
Argomento(i)
Meccanismo di finanziamento
ERC-STG - Starting GrantIstituzione ospitante
44801 Bochum
Germania