An improved 12-step syntheticroute and full characterization of hexaphenyl-carbo-benzene (4, 8%) and the p-bis-3,5-di-tert-butylphenyl homologue (11, 4%), are described. The carbo-benzene reference 4 is now accurately described in the crystal state by X-ray diffraction analysis in the chiral space group P212121, and in comparison to the less symmetric derivative 11 exhibiting a centro-symmetric packing
eliminative aromatization of sila[5]pericyclyne precursors with adjacent C─OR and C─H vertices. The synthesis of tetraoxy-sila[5]pericyclyne representatives (“carbo-silolanes” 2a and 2b ) has been tackled through several [(15–n)+n] ring formation strategies. After having first attempted a [14+1] route from dichlorodiphenylsilane and a skipped pentayne ( 3 ), a [5+10] route proceeded successfully from
carbo‐Benzene is an aromatic molecule devised by inserting C2 units within each C−C bond of the benzene molecule. By integrating the corresponding carbo‐quinoid core as bridging unit in a π‐extended tetrathiafulvalene (exTTF), it is shown that a carbo‐benzene ring can be reversibly formed by electrochemical reduction or oxidation. The so‐called carbo‐exTTF molecule was thus experimentally prepared and studied
used [11+7] strategy, the [14+4] and [8+10] strategies were thus explored. They proved to be efficient, affording seven novel hexaoxy[6]pericyclynes corresponding to six different substitution patterns. These compounds were obtained in 7-15 steps as mixtures of stereoisomers. Thus, by using dibenzoylacetylene as the C(4) electrophile, a [14+4] strategy allowed the synthesis of two hexaphenyl representatives
Stable dichromic carbo-cyclohexadiene chromophores are synthesised, selectively with respect to the corresponding carbo-benzenes, by fluorine “chemical locking”.