Arylisoquinoline-derived organoboron dyes with a triaryl skeleton show dual fluorescence

• Vânia F. Pais,
• Tristan Neumann,
• Ignacio Vayá,
• M. Consuelo Jiménez,
• Abel Ros and
• Uwe Pischel

Beilstein J. Org. Chem. 2019, 15, 2612–2622, doi:10.3762/bjoc.15.254

• hinders the free rotation around axis A (Scheme 3) of the compounds 16–19; therefore, complex mixtures of the syn/anti atropoisomers (0.45:0.55; syn:anti) were observed in NMR spectroscopy. To facilitate the C–C bond rotation around axis B (Scheme 3) and simplify the NMR spectra, the measurements were

Calix[6]arene-based atropoisomeric pseudo[2]rotaxanes

• Carmine Gaeta,
• Carmen Talotta and
• Placido Neri

Beilstein J. Org. Chem. 2018, 14, 2112–2124, doi:10.3762/bjoc.14.186

• axle. In all the examined cases, the 1,2,3-alternate and cone atropoisomers are, respectively, the kinetic and the thermodynamic ones. Keywords: atropoisomers; calixarene; conformation; pseudorotaxane; social isomerism; Introduction Mechanomolecules [1][2][3][4], such as rotaxanes and catenanes show

• of the axle. In all the examined cases, the 1,2,3-alternate and cone atropoisomers are the kinetic and thermodynamic pseudorotaxane, respectively. We do believe that novel and intriguing calixarene-based mechanomolecules, with expanded properties or functions, could be obtained by an appropriate

• pseudorotaxane atropoisomers calculated at B3LYP/6-31G(d,p) level of theory and using Grimme’s dispersion corrections (IOp(3/124 = 3)). The two pseudorotaxane atropoisomers obtained by threading hexahexyloxycalix[6]arene 1 with monostoppered alkylbenzylammonium axle 6+. The two pseudorotaxane atropoisomers

Ring strain and total syntheses of modified macrocycles of the isoplagiochin type

• Andreas Speicher,
• Timo Backes,
• Kerstin Hesidens and
• Jürgen Kolz

Beilstein J. Org. Chem. 2009, 5, No. 71, doi:10.3762/bjoc.5.71

• . The existence of atropoisomers [3] prompted us to perform detailed studies on the chirality of 1 and 2 including HPLC-CD experiments. Assuming the existence of three formal stereogenic elements A–C (Figure 1), a total of up to 23 = 8 conformers (four diastereomers with their enantiomers) in principle