Stereochemical Investigation of the Products of the Photoinduced Perfluoroalkylation–Dimerization of Anthracene

The photoinduced perfluoroalkylation of anthracene has been shown to provide 9,9′,10,10′-tetrahydro-10,10′-diperfluoroalkyl-9,9′-bianthracenes in over 70% yields, each perfluoroalkyl iodide producing three diastereomers. The structures of all three diastereomers (<i>cis</i>,<i>cis</i>, <i>cis</i>,<i>trans</i>, and <i>trans</i>,<i>trans</i> isomers) have been elucidated by both NMR and X-ray crystallographic analyses. Most notably, an X-ray crystallographic analysis has revealed that the <i>trans</i>,<i>trans</i> diastereomer having the two trifluoromethyl groups in 10,10′-positions adopts a 74° twisted relationship of the two dihydroanthracene rings. Furthermore, each of the two <i>trans</i>,<i>trans</i> isomers <b>2a</b>,<b>b</b> has been shown to exist as a mixture of new types of atropisomers and the energy barrier for the interconversion of the two atropisomers has been estimated to be 12 kcal/mol by variable-temperature NMR analysis

Eosin Y‑Catalyzed Visible-Light-Induced Hydroperfluoroalkylation of Electron-Deficient Alkenes

The eosin Y-catalyzed hydroperfluoroalkylation of electron-deficient alkenes is described herein. The reaction proceeded smoothly under visible light irradiation and selectively afforded a hydroperfluoroalkylated product. Various perfluoroalkyl bromides and electron-deficient olefins can be used in this reaction, and all chemicals required for this reaction are safe and readily available

10-Phenylphenothiazine-Organophotocatalyzed Bromo-Perfluoroalkylation of Unactivated Olefins

In this study, we have developed a smooth metal-free visible-light-induced bromo-perfluoroalkylation of unactivated olefins with the aid of 10-phenylphenothiazine (PTH) as an organic photoredox catalyst. The reaction is 100% atom-economic redox-neutral and proceeds with stoichiometric amounts of olefin and perfluoroalkyl bromide. To show the potential of these unexplored motifs, we carried out various postfunctionalizations taking advantage of the bromine atom, including gram-scale experiments

Unusual Molecular and Supramolecular Structures of Chiral Low Molecular Weight Organogelators with Long Perfluoroalkyl Chains

Gels composed of low molecular weight gelators (LMWGs) are fascinating research targets from the viewpoint of applications because their functionalities are easily modified by designing their molecular structures. Some reliable gelator design approaches have been developed. However, new classes of molecular gelators are sometimes discovered unexpectedly, suggesting that there remain unknown aspects about gelators. To obtain knowledge regarding gelation and crystallization ability, the crystal structure of <i>N,N</i>′-diperfluorooctanoyl-(1<i>R</i>,2<i>R</i>)-1,2-diaminocyclohexane (<i>RR</i>-CF8), which is a derivative of 1,2-diaminocyclohexane, one of the most famous LMWGs, was investigated in addition to the vibrational circular dichroism (VCD) measurements. The crystal structure was solved from powder X-ray diffraction patterns because recrystallization of <i>RR</i>-CF8 afforded no suitable single crystals for single crystal X-ray diffraction measurement. Two unusual structural features were confirmed. One is that the perfluoroalkyl chain (PFC) of <i>RR</i>-CF8 forms a pseudoracemic helix, or a mixture of right- (<i>P</i>) and left-handed (<i>M</i>) helices, while elsewhere, PFCs generally have one-handed helicity. The other is that an oxygen atom of one of the amide groups is free of hydrogen bonds, reducing the stability of one-dimensional hydrogen-bonded assemblies. These unique structural features let us propose the reasonable explanations for the gelation and crystallization ability of <i>RR</i>-CF8. Furthermore, a factor of environment-dependent chirality inversion of <i>RR</i>-CF8 supermolecules was clarified by combining X-ray crystallography and solid-state VCD spectroscopy