Syntheses and Different Chemical Behaviour of Precursors of Putative Dibasic Inhibitors of Human Mast Cell Tryptase
摘要:
Choosing the best conditions and pathways for the synthesis of peptidic compounds remains a challenge for the peptide chemist. Our efforts towards the syntheses of two precursors of potential tryptase inhibitors, building block A and B, led to the development of two different synthesis routes. Each of them is successful in the synthesis of only one of the two, structurally nearly identical target compounds.
Nanostaircase formation in the solid state from self-assembling synthetic terephthalamides with a common molecular scaffold
作者:Sudipta Ray、Raghurama P. Hegde、Apurba Kumar Das、N. Shamala、Arindam Banerjee
DOI:10.1016/j.tet.2006.07.092
日期:2006.10
The design and construction of nanostructured materials using proper self-assembling molecular building blocks is a real challenge to scientists. Here, we present the formation of a new nano-architecture, i.e., nanostaircase in the solid state by using molecular building blocks, which are amenable to self-assembly in a directed manner to form the specific nanostructure. The molecular building blocks are terephthalamides 1-4, which are bis-terephthalamides of methyl esters of various alpha-amino acids including L-leucine 1, D-leucine 2, L-isoleucine 3, and alpha-aminoisobutyric acid (Aib) 4. All terephthalamides presented here, irrespective of their different side chain residues or stereochemistry, self-assemble to form supramolecular nanostaircase structures in crystals. Each terephthalamide contains two good hydrogen-bond donors and two hydrogen-bond acceptors. Two N-H center dot center dot center dot O hydrogen bonds and C-H center dot center dot center dot pi interactions are responsible for the formation and stabilization of the nanostaircase structures in crystals. The molecular building blocks are packed orthogonally to each other in crystals and this arrangement can help the formation of nanostaircase structure upon self-assembly. (c) 2006 Elsevier Ltd. All rights reserved.