Molecular scaffolding

The BZ stmcture also has provided a molecular scaffold for a number of peptide receptor ligands (26). Antagonists for the cholecystokinin (CCK-A) receptor, eg, devazepide (65), the thyrotropin-releasing hormone (TRH) receptor, eg, midazolam (66), and the /i -opiate receptor, eg, tifluadom (67), as well as a series of ras famyl transferase inhibitors, eg, BZA-2B (68) (30) have been identified (Table 4). 

Diederich F, Gobbi L (1999) Cyclic and Linear Acetylenic Molecular Scaffolding. 201 43-79... 

Keywords Acetylene chemistry. Cross-coupling reactions, Cyclo[n]carbons, Expanded radialenes. Molecular scaffolding. Nanostructures, Perethynylated chromophores, Poly(triacetylene), Tetraethynylethene. 

This article summarizes efforts undertaken towards the synthesis of the cyclo[ ]carbons, the first molecular carbon allotropes for which a rational preparative access has been worked out. Subsequently, a diversity of perethynylated molecules will be reviewed together, they compose a large molecular construction kit for acetylenic molecular scaffolding in one, two and three dimensions. Finally, progress in the construction and properties of oligomers and polymers with a poly(triacetylene) backbone, the third linearly conjugated, non-aromatic all-carbon backbone, will be reviewed. 

In contrast, the synthesis of tetraethynylethene (TEE, C10H4) was described in 1991 and, since then, a rich variety of cyclic and acyclic molecular scaffolds incorporating this carbon-rich molecule as a construction module have been prepared. The majority of these compounds, such as the expanded radialenes or the oligomers and polymers of the poly(triacetylene) type, are highly stable and... 

Acetylene- and Diacetylene-Expanded Cycloalkanes and Rotanes. 201 1 - 42 Diederich F, Gobbi L (1999) Cyclic and Linear Acetylenic Molecular Scaffolding. 20J 43 - 79 Gobbi L, see Diederich F (1999) 201 43 -129... 

The molecular scaffolds also provide an unusual opportunity for the identification and recognition of meso structures. For example, successive acylation of L and D phenylalanine with the acridine diacid gives the structure 56 and we anticipate that... 

The surface of each layer has two types of single stranded arms (e.g. one 3 — 5 and one 5 — 3 strand) which can bind to other monomers to render 1st-and 2nd-generation dendrimers 25 and 26. Therefore the molecular scaffold grows exponentially with each sequential layer of hybridization. If an oligonucleotide contains a sequence complementary to those at the surface of these networks it should be hybridized. The remaining free sequences from the other type of arms then bind in a standard nucleic acid blot (after they are bound to... 

There continues to be interest in small-molecular scaffolds as good starting points for drug discovery [50]. Indoles [51], 2-oxindoles [52], 2-arylben-zothiazoles [53], rhodanines [54], quinolones [55], (3-D-glucose [56], and y-pyrones [57] have all recently been reviewed as "privileged" scaffolds. 

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