Details

Autor(en) / Beteiligte

• Zhang, Wei
• Moore, Jeffrey S.

Titel

Shape-Persistent Macrocycles: Structures and Synthetic Approaches from Arylene and Ethynylene Building Blocks

Ist Teil von

• Angewandte Chemie International Edition, 2006-07, Vol.45 (27), p.4416-4439

Ort / Verlag

Weinheim: WILEY-VCH Verlag

Erscheinungsjahr

2006

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Shape‐persistent arylene ethynylene macrocycles have attracted much attention in supramolecular chemistry and materials science because of their unique structures and novel properties. In this Review we describe recent examples of macrocycle synthesis by cross‐coupling (Sonogashira: aryl acetylene macrocycle or Glaser: aryl diacetylene macrocycle) and dynamic covalent chemistry. The primary disadvantage of the coupling methods is the kinetically determined product distribution, since a significant portion of oligomers grow beyond the length of the cyclic targets (“overshooting”). Better results have been obtained recently by a dynamic covalent approach involving reversible metathesis reactions that afford macrocycles in one step. Mechanistic studies demonstrate that macrocycle formation is thermodynamically controlled by this route. Remaining synthetic challenges include the efficient preparation of site‐specifically functionalized structures and larger, more complex two‐ and three‐dimensional molecules. Balance control: Kinetically controlled cyclooligomerization is impeded by the formation of higher oligomers (“overshooting”). Under reversible conditions, the product distribution is determined by the thermodynamic stability, which is balanced by both entropic and enthalpic factors. Methods based on dynamic covalent chemistry and the use of the energy gap principle enable the formation of target macrocycles by cyclooligomerization to be controlled.