First bile acid-derived chiral dendritic species with nanometric dimensions

Abstract

The chemistry of dendrimers has been a dominating theme in chemical sciences in recent years. Chiral dendritic species1 also appeared in the chemical literature shortly after the first achiral version was reported.2 Apart from their potential applications in asymmetric catalysis and chiral recognition,3 chiral dendritic species have been of considerable interest because of a search towards macromolecular asymmetry.4 A dendrimer possesses three distinct regions, viz. the core, the branching units and the end groups, and the incorporation of chirality in the dendrimer can in general be achieved by choosing one or more such components to be chiral.1b Molecules from the natural chiral pool, e.g. amino acids,1a nucleic acids,5 sugars6 and tartaric acid,4e,f have been employed to design chiral dendrimers. Bile acids, forming another class of the naturally occurring group of chiral molecules, have been extensively used in supramolecular chemistry including the synthesis of cyclic and linear polymers.7 Bile acids (e.g. 1–3) offer a carboxy group and multiple