Asymmetric Synthesis and Chiroptical Properties of Enantiopure Helical Ferrocenes
作者:Antonio Urbano、Ana M. del Hoyo、Alicia Martínez-Carrión、M. Carmen Carreño
DOI:10.1021/acs.orglett.9b01522
日期:2019.6.21
An enantiopure helical ferrocene (Rp)-5 with five ortho-condensed aromatic rings was synthesized using a PtCl2-catalyzed cycloisomerization of planar-chiral 2-ethynyl-1-(4-phenanthrenyl)ferrocene (Rp)-6f, prepared in 3 steps from known enantiopure sulfinyl ferrocenyl boronic acid (SS,Sp)-7, as the source of planar chirality. This pentacyclic helical ferrocene showed a very high optical rotation value
Substituent effects on the photochromic properties of 3,3-diphenyspiro[benzofluorenopyran-cyclopentaphenanthrene]s
作者:Junji Momoda、Shinobu Izumi、Yasushi Yokoyama
DOI:10.1016/j.dyepig.2015.03.019
日期:2015.8
The introduction of electron-donating groups on the skeleton of a naphthopyran, 3,3-diphenyspiro[benzofluorenopyran-cyclopentaphenanthrene], has led to the development of a photochromic dye applicable to photochromic lenses. Introducing a methoxy group to C6 moved the absorption band of the MC form towards the longer wavelength. Further introduction of methoxy groups to the para-position of the phenyl
C−H Bond Activation for the Synthesis of Heterocyclic Atropisomers Yields Hedgehog Pathway Inhibitors
作者:Gang Shan、Jana Flegel、Houhua Li、Christian Merten、Slava Ziegler、Andrey P. Antonchick、Herbert Waldmann
DOI:10.1002/anie.201809680
日期:2018.10.22
pronounced bioactivity, and methods for their efficient synthesis have gained widespread attention. However, enantioselective synthesis of axially chiral 4‐arylisoquinolones by means of C−Hactivation has not been reported to date. Described here is a rhodium (III)‐catalyzed C−Hbondactivation and annulation for the atroposelective synthesis of axially chiral 4‐arylisoquinolones. The method employs