22717-94-8Relevant articles and documents
Efficient Enantioselective Synthesis of Oxahelicenes Using Redox/Acid Cooperative Catalysts
Sako, Makoto,Takeuchi, Yoshiki,Tsujihara, Tetsuya,Kodera, Junpei,Kawano, Tomikazu,Takizawa, Shinobu,Sasai, Hiroaki
, p. 11481 - 11484 (2016)
An efficient and enantioselective synthesis of oxa[9]helicenes has been established via vanadium(V)-catalyzed oxidative coupling/intramolecular cyclization of polycyclic phenols. A newly developed vanadium complex cooperatively functions as both a redox and Lewis acid catalyst to promote the present sequential reaction and afford oxa[9]helicenes in good yields with up to 94% ee.
Selective Borylation of [4]Helicene
Ne?as, David,Kaiser, Reinhard P.,Ul?, Jan
, p. 5647 - 5652 (2016/12/14)
The Ir-catalyzed borylation of [4]helicene under different reaction conditions was studied for the first time. The results indicate that monoborylation proceeds to give a mixture of 2- and 3-borylated products in good yields (up to 74 % isolated yield). It was possible to shift the selectivity in favor of the 3-borylated product by using sterically demanding ligands. The monoborylated [4]helicenes were further arylated by using a Suzuki–Miyaura cross-coupling or oxidized to the corresponding phenols in very good yields.
