Novel supramolecular affinity materials based on (−)-isosteviol as molecular templates

• Christina Lohoelter,
• Malte Brutschy,
• Daniel Lubczyk and
• Siegfried R. Waldvogel

Beilstein J. Org. Chem. 2013, 9, 2821–2833, doi:10.3762/bjoc.9.317

• particular as templates for tracing air-borne arenes at low concentration. The affinities of the synthesized materials towards different air-borne arenes were determined by 200 MHz quartz crystal microbalances. Keywords: affinity materials; (−)-Isosteviol; supramolecular chemistry; triphenylene ketals

• ][6][7][8][9][10]. Particular interest was given to C3-symmetric structures, serving e.g. as templates in asymmetric catalysis or molecular recognition [11][12][13][14]. A specific but potent subclass of such C3-symmetric architectures is represented by triphenylene ketals [15]. They have found

• [38][39], Within in a nine-step synthesis triphenylene ketals based on (−)-isosteviol were prepared [40]. Receptor structures 2 equipped with amino or sulfonylamido functionalities were obtained (Figure 2). In addition to triphenylene ketals, triptycene-based structures also exhibit the geometrical

Efficient electroorganic synthesis of 2,3,6,7,10,11-hexahydroxytriphenylene derivatives

• Carolin Regenbrecht and
• Siegfried R. Waldvogel

Beilstein J. Org. Chem. 2012, 8, 1721–1724, doi:10.3762/bjoc.8.196

• Anodic oxidation of catechol ketals We report a simple protocol for the anodic oxidation of catechol ketals forming triphenylene ketals (Scheme 1). Best results were obtained in PC and TMABF4 (method A) or TBABF4 (method B) as electrolytes. Performing the reaction in PC is beneficial for several reasons

• : PC is hazard-free, inexpensive and suitable for large-scale reaction. Moreover, triphenylene ketals have lower oxidation potentials than the corresponding catechol ketals. Since the non-polar products exhibit a relative poor solubility in PC, precipitation is achieved during the electrolysis. Usually

• . However, our method provides easy access to pure 3 which can easily be separated and purified by simple filtration. Conclusion Triphenylene ketals are easily available by anodic oxidation using a simple galvanostatic protocol. Best results are obtained when the synthesized dehydrotrimers are almost