Syntheses of [5]-helicene by McMurry or carbenoid couplings

Efficient Phenanthrene, Helicene, and Azahelicene Syntheses

“…[10] The challenge of developing efficient routes to helicenes that are amenable to scale-up has inspired many imaginative approaches, [11,12] including strategies based on Diels-Alder cycloadditions, [13] carbenoid insertions, [14] radical cyclizations, and metal-mediated cycloisomerizations. [15,16] Herein, we report a short and efficient entry to helicenes, azahelicenes, and phenanthrenes in which the use of halo and alkoxy substituents to control both the stereochemical course of Wittig reactions and the regiochemical course of homolytic aromatic substitution reactions is a key feature.…”

Efficient Phenanthrene, Helicene, and Azahelicene Syntheses

“…10 Though useful, complex product mixtures often arise as a result of poor regiocontrol in the photocyclization step or competitive side reactions, such as photo‐induced dimerization or benzo[ ghi ]perylene formation 10. The challenge of developing efficient routes to helicenes that are amenable to scale‐up has inspired many imaginative approaches,11, 12 including strategies based on Diels–Alder cycloadditions,13 carbenoid insertions,14 radical cyclizations, and metal‐mediated cycloisomerizations 15. 16 Herein, we report a short and efficient entry to helicenes, azahelicenes, and phenanthrenes in which the use of halo and alkoxy substituents to control both the stereochemical course of Wittig reactions and the regiochemical course of homolytic aromatic substitution reactions is a key feature.…”

Effective HPLC resolution of [4]heterohelicenium dyes on chiral stationary phases using reversed‐phase eluents

“…In some examples, high level of asymmetric inductions have been achieved. 4, [51][52][53][54][55][56][57][58][59] Previously, 1,13-dimethoxyquinacridinium cation 1a was reported (R ¼ n Pr, Fig. 1).…”