Synthesis and Conformational Study of Water-Soluble, Rigid, Rodlike Oligopiperidines

摘要

Herein, we describe the preparation of oligopiperidines as a new family of water-soluble, rigid oligomers. The design of molecules with nanometer dimensions, defined shapes, and physical properties (solubility, conductivity, etc.) is a matter of considerable interest in macromolecular chemistry.[1], [2] Molecular rods are rigid, linear macromolecules that constitute promising materials for applications in nanotechnology, such as spacers, wires, and construction elements.[3] The poor water solubility of many current examples of molecular rods[1], [4] limit their applications, particularly in biology. Only a few bio-oligomers exhibit a rigid-rod structure,[2c] of which oligoprolines, which have been considered the most rigid,[5] have been used as spacers in biochemistry.[6] The structure of these compounds is, however, still a subject of discussion. Levins and Schafmeister reported the synthesis of a water-soluble molecular rod based on fused diketopiperazine oligomers starting from a complex building block.[7]