Expanding amphiphilic architectures by ring-opening of epoxides and polyepoxides with N-methyl-d-glucamine: Structure, chiral bias and gelation

Abstract

The facile reaction of a readily available aminopolyol from the chiral pool, N-methyl-d-glucamine, which avoids the side reactions usually associated to anomers of amino sugars, with epoxide and polyepoxide derivatives, enables the preparation of new non-ionic surfactant-like structures combining hydrophilic and hydrophobic moieties. The molecular architectures thus obtained range from linear to tripodal and pyramidal structures. The resulting substances containing multiple chiral centers exist as diastereomeric mixtures, for which various conformations are likewise possible by virtue of inter-chain interactions. The stability and chirality preferences of all possible stereoisomers have been evaluated in detail by DFT methods. Given the amphiphilic structure of both protected and O-protected derivatives obtained by acetylation, self-aggregation could eventually lead to solvent entrapment. Unfortunately, only one compound behaves as efficient hydrogelator and DMSO-gelator at low concentrations. The issue is also discussed in terms of the different molecular arrangements.