Revisiting Butafulvene Formation by Thermal Dimerization of Fluorene-Based Dialkynes - Effects of Aromatic Substituents.

Butafulvenes, together with pentafulvenes and [3]radialenes, form a series of constitutional benzene isomers in which aromaticity changes significantly and can be strongly substituent dependent. Butafulvene, as a member of this series, is frequently proposed to be antiaromatic. Based on butafulvenes Hopf, Zimmerman and coworkers first time described, derivatives thereof were synthesized and the effects of substituents on both the stability of the intermediate isobenzenes and on their optoelectronic and (anti)aromatic properties are discussed.

High-Yielding Nanobelt Formation by Chirality-Assisted Synthesis.

Shape-persistent conjugated nanobelts (CNBs) are fascinating synthetic targets. However, in most cases these are made in low overall yields by applying strategies of macrocyclization followed by (multiple) ring fusion reactions for nanobelt formation. Here, we describe the high yielding synthesis of enantiopure chiral nanobelts in 84 % yield by applying chirality-assisted synthesis (CAS).

A Negatively Curved Nanographene with Four Embedded Heptagons.

Negatively curved nanographenes are considered as cutouts of three-dimensional fully sp-hybridized carbon allotropes such as Schwarzites. Here we present the synthesis of a C cut-out of the Schwarzite 8-4-1-p proposed by Lenosky et al. and investigate its optical as well as electrochemical properties.

Substituent Effects in Scholl-Type Reactions of 1,2-Terphenyls to Triphenylenes.

A series of 3,3''- and 4,4''-dimethoxy terphenyls with different second substituents on their ortho-positions have been synthesized and investigated upon the possibility to be oxidatively cyclodehydrogenated to the corresponding triphenylenes under Scholl-type conditions. The experimentally obtained selectivities were supported and explained by quantum chemical calculations and conclusions on the involved mechanisms (acid catalyzed arenium-ion mechanism (AIM) vs radical cation mechanism) were drawn.