191848-37-0Relevant academic research and scientific papers
Selective and gram-scale synthesis of [8]cycloparaphenylene
Ishida, Kosuke,Kawanishi, Tatsuya,Kayahara, Eiichi,Yamago, Shigeru
, p. 2082 - 2091 (2020)
Selective and large-scale synthesis of [8]cycloparaphenylene (CPP) was achieved in seven steps starting from commercially available 4-bromo-4′-hydroxybiphenyl and 4,4′-dibromobiphenyl. The key unsymmetrical tetraring unit, 4-bromophenyl and 4′-bromobiphenyl-substituted cis-1,4-bis(triethylsiloxy)-2,5-cyclohexadiene-1,4-diyl (5fA), was synthesized on an ～50 g scale by stereoselective cis-addition of 4-bromo-4′-lithiobiphenyl to 4-(4-bromophenyl)-4-hydroxy-2,5-cyclohexadien-1-one, which was synthesized on an ～100 g scale. Platinum-mediated selective dimerization of the four-ring unit 5fB and subsequent reductive aromatization of the cyclohexadiene-diyl by H2SnCl4 gave 2 g of [8]CPP in 6.6% overall yield (10.2% on small scale).
Selective synthesis of strained [7]cycloparaphenylene: An orange-emitting fluorophore
Sisto, Thomas J.,Golder, Matthew R.,Hirst, Elizabeth S.,Jasti, Ramesh
supporting information; experimental part, p. 15800 - 15802 (2011/11/13)
[n]Cycloparaphenylenes, which are short fragments of carbon nanotubes, have unique size-dependent optical properties. In this communication, we describe the first synthesis of [7]cycloparaphenylene ([7]CPP), the smallest cycloparaphenylene prepared to date. In order to access this structure, we have developed a synthetic route that capitalizes on successive orthogonal Suzuki-Miyaura coupling reactions. [7]CPP has 83 kcal/mol of strain energy and an orange emission at 592 nm.
