Acetylenic scaffolding

Fig. 3. Known and hitherto elusive perethynylated building blocks for two- and three-dimensional acetylenic scaffolding. The only compounds shown are those with either free or silyl-protected ethynyl groups...

Diederich F (1997) Tetraethynylethenes Versatile Carbon-rich Building Blocks for Two-dimensional Acetylenic Scaffolding. In Michl J (ed) Modular Chemistry. Kluver,... 

Figure 6. Examples for known perethynylated building blocks for two-dimensional acetylenic scaffoldings.

Shape-Persistent Macrocycles Based on Acetylenic Scaffolding... 

Manini, P Amrein, W. Gramlich, V. Diederich, F. Expanded cubane synthesis of a cage compound with a C56 core by acetylenic scaffolding and gas-phase transformations into fullerenes, Angew. Chem. Int. Ed. 2002,4339-4343. 

Utesch, N. F., Diederich, F. Acetylenic scaffolding on solid support Poly(triacetylene)-derived oligomers by Sonogashira and Cadiot-Chodkiewicz-type cross-coupling reactions. Org. Biomol. Chem. 2003,1, 237-239. 

In 1990, Gorgues and coworkers [60,61] reported the earliest studies of extended TTFs by acetylene scaffolding 61, in order to decrease on-site Coulomb repulsion. The symmetrically substituted acetylenic analog 61 was prepared from a very reactive aldehyde (58) [62] by Wittig or Horner-Wadsworth-Emmons reactions (Scheme 8.8). The CV of 61 exhibited reversible one two-electron redox pan-corresponding to 61/61 . This behavior is different from the TTFVs series of 2, which is linked by an ethylene spacer, due to lack of electronic communication through the acetylenic bond in 61 ". ... 

The Y-shaped l,3-dithiole-2-ylidene unit, inserted into an acetylene scaffold, was also utilized as a building block for a two-dimensional network in crystals. Yamashita and coworkers [71] have constructed the cross-conjugated system 71... 

Pericyclines are macrocyclic structures, in which saturated comer atoms are connected by ethynyl linkages [28-30]. Examples where this acetylenic scaffolding [31-35] is extended in three-dimensional space are the exploded cubane 14 [36] and cyclophane 15 [37-39] (Fig. 2.5). Few silapericyclines [40-49] are known and those with other heteroatoms are even rarer [50]. Attempts to synthesize the parent 3D analogues of the phosphapericyclines [51], tetrahedron 16, and cubes 17 and 18 (Fig. 2.6) were unsuccessful [52, 53]. DFT calculations indicated the cubes to exhibit cyclic delocalization, as suggested by the elongated... 

Diederich F (2001) Carbon-rich acetylenic scaffolding rods, rings and switches. Chem Commun 219-227... 

Nielsen MB, Diederich F (2002) The art of acetylenic scaffolding rings, rods, and switches. Chem Rec 2 189-198... 

Kivala M, Mitzel F et al (2006) Two-dimensional acetylenic scaffolding extended donor-substituted perethynylated dehydroannulenes. Chem Asian J 1 479 89 Nielsen MB, Diederich F (2005) Conjugated oligoenynes based on the diethynylethene unit. Chem Rev 105 1837-1867... 

---