Schalen, Reifen und Sattel: Methoden zur Synthese gebogener aromatischer Moleküle

Abstract

Dieser Aufsatz fast die jüngsten Fortschritte in der Chemie gekrümmter aromatischer Moleküle zusammen. Mit dem Schwerpunkt auf den wesentlichen Erfolgen des vergangenen Jahrzehnts stellen wir einen allgemeinen Überblick über die Synthesemethoden zur Verfügung, die eine effiziente Induktion von interner Spannung in π‐konjugierten Strukturen ermöglichen. Dieser Aufsatz ist gemäß der am spannungsinduzierenden Reaktionsschritt (Cyclisierungen, Eliminierungen, Ringexpansionen und –kontraktionen) beteiligten Topologieänderung gegliedert und unterstreicht die bemerkenswerte Vielfalt an Strukturen, die mit modernen Synthesemethoden erzielt werden kann.

Stereoselective Syntheses, Structures, and Properties of Extremely Distorted Chiral Nanographenes Embedding Hextuple Helicenes

“…[1] Because PA Hs are somewhat flexible and stretchable molecules,i ta llows the design of curved PA Hs such as bowls,s addles,c oiled ribbons,p ropellers,and circular belts with defined molecular chirality. [2] The latter property is of ag reat interest in life,c hemical, and physical sciences as well as in technology,because it allows an additional tuning of molecular properties and functions for many applications. [3] Large chiral PA Hs have thus become molecules of utmost interest as three-dimensional chiral nanographenes,and small curved PA Hs are now often sought as building blocks for their construction in the racemic series.…”

Triskelion‐Shaped π‐Luminophores Bearing Coumarin: Syntheses, Structures, and Luminescence Properties

“…In recent years, π-curved aromatic molecules have come to the fore due to their solubility in organic solvents and unusual physical properties resulting from the molecular scaffold and curved π-plane. [22] In addition, the non-planarity of fluorogenic molecules may lead to unique characteristics such as aggregation-induced emission (AIE) or aggregation-induced emission enhancement (AIEE). [23] Therefore, we attempted the synthesis of π-curved coumarin derivatives (1, Figure 2b), which is expected to twist by intramolecular steric hindrance between the carbonyl unit and adjacent benzene moiety.…”

“…These fluorogenic π‐conjugated coumarins show favorable emission characteristics with a bathochromic shift but at the expense of their solubility in common organic solvents due to their planar structure and rigid framework. In recent years, π‐curved aromatic molecules have come to the fore due to their solubility in organic solvents and unusual physical properties resulting from the molecular scaffold and curved π‐plane . In addition, the non‐planarity of fluorogenic molecules may lead to unique characteristics such as aggregation‐induced emission (AIE) or aggregation‐induced emission enhancement (AIEE) .…”

Synthesis of a Strained Spherical Carbon Nanocage by Regioselective Alkyne Cyclotrimerization

“…[1] In order to achieve this synthesis,overcoming molecular strain is crucial. [1] In order to achieve this synthesis,overcoming molecular strain is crucial.…”

“…The synthesis of highly strained cyclic p-conjugated molecules,possessing bent benzene rings,has been attracting much attention as ac hallenging target in organic synthesis. [1] In order to achieve this synthesis,overcoming molecular strain is crucial. In 2008, Jasti reported the elegant synthesis of cyclic paraphenylene rings,[ 9], [ 12],a nd [18]cycloparaphenylenes (CPPs), through the multiple coupling reactions followed by reductive aromatization of cyclohexadiene template A (R = Me).…”