Acenaphthenoannulation Induced by the Dual Lewis Acidity of Alumina

Abstract

We have discovered a dual (i. e., soft and hard) Lewis acidity of alumina that enables rapid one-pot πextension through the activation of terminal alkynes followed by CÀ F activation. The tandem reaction introduces an acenaphthene fragment -an essential moiety of geodesic polyarenes. This reaction provides quick access to elusive[a] Dr.

A Macrocyclic Tweezers‐Shaped Receptor for the Biomimetic Recognition of the Gal(α1‐3)Gal Disaccharide of the α‐Gal Antigen

“…Receptor 3 was easily synthesized in three steps with 54 % overall yield starting from two readily available building blocks, 2,7‐naphthalenedicarboxaldehyde ( 4 ) [30] and diaminocarbazole ( 5 ), [22] prepared according to previously described procedures. Macrocyclization was carried out in a one‐pot reaction, using an equimolar mixture of 4 and 5 in CHCl 3 , which was refluxed overnight before NaBH 4 in methanol was added to reduce the formed imines, affording the tetraamine 6 in 60 % yield.…”

Synthesis and Properties of Diindeno[1,2,3‐cd:1′,2′,3′‐mn]pyrene and Two of Its Aza‐Analogs

“…[21] Recently, the group of Amsharov developed a synthetic strategy to non-alternant PAHs using activated γ-alumina. [22] Despite these recent advancements, there is still a lack of synthetic methodologies towards those C 70 substructures. In addition, the implementation of heteroatoms to alter the optical and electrochemical properties has, to the best of our knowledge, not been reported to date.…”

“…Later, the group of Mastalerz revisited the synthesis of tetraindopyrene and diindenopyrenes and demonstrated their application as p‐channel charge carriers [21] . Recently, the group of Amsharov developed a synthetic strategy to non‐alternant PAHs using activated γ‐alumina [22] …”

Modular Synthesis of a Semibuckminsterfullerene

“…A 2019 paper by Amsharov and co-workers described a method for the synthesis of diindenochrysenes through a remarkable intramolecular dehydrofluorination on activated neutral alumina at moderate temperatures (<250 °C). − The mechanism has been described as a dyotropic rearrangement driven by the formation of a strong Al–F bond . Siegel and co-workers have made groundbreaking contributions to this area, including a nonpyrolytic corannulene synthesis on the kilogram scale. − The same kind of bond-forming reaction that is accomplished by the Amsharov procedure on alumina was performed by Siegel and co-workers in solution through activation of an aromatic C–F bond with silylium ions .…”