Université de Neuchâtel

Synthèse, caratérisation et étude de composés liquides-cristallins du fullerène : poly-adduits et bis-méthanofullerènes chiraux

Gottis, Sébastien ; Deschenaux, Robert (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2008 ; Th.2032.

Liquid crystals play a crucial role in new technologies. Indeed, in a society in which audio and video media are increasingly used by more and more people, organic liquid crystals have a bright future. On the other hand, chemicals like fullerenes, which display unique physical and chemical properties, are appealing compounds for the design of multifunctional liquid-crystalline materials. In this...

Université de Neuchâtel

The High Stereoselectivity of the Tandem Sequence Diels-Alder Reaction/Ireland­-Claisen Rearrangement Starting from Substituted O-(E)-Buta-1,3-dienyl Ketene Acetals and Cyclic Dienophiles

Soldermann, Nicolas ; Velker, Jörg ; Neels, Antonia ; Stoeckli-Evans, Helen ; Neier, Reinhard

In: Synthesis, 2007, vol. 15, p. 2379-2387

A new tandem reaction leads to bicyclic cyclohexene derivatives with complete control of the relative configuration of the four chiral centers formed. The high diastereoselectivity is the consequence of an endo-selective Diels-Alder reaction followed by an Ireland-Claisen rearrangement that proceeds via a boat-like transition state.