136984-20-8Relevant articles and documents
Regioselective Synthesis of 4,7,12,15-Tetrasubstituted [2.2]Paracyclophanes: A Modular Route Involving Optical Resolution
Biliz, Fatmanur,Cakici, Murat
supporting information, p. 4828 - 4834 (2021/09/20)
A practical synthetic method for preparing bis-(para)-pseudo-ortho and bis-(para)-pseudo-meta type 4,7,12,15-tetrasubstituted [2.2]paracyclophanes is reported. Regioselective double Rieche formylation was successfully applied to the corresponding dibromo[2.2]paracyclophanes under slightly modified conditions. Aldehydes reacted in an unknown direction with Rieche formylation agents, dichloromethyl methyl ether and titanium(IV) tetrachloride, leading to the formation of benzal chlorides. Formylated products were obtained after hydrolysis of these benzal chloride derivatives. Optical resolution was performed with the diastereomer method and (RP)-4,12-dibromo-7,15-diformyl[2.2]paracyclophane was successfully obtained in an enantiomerically pure form (99 % ee). Their synthetic utility is demonstrated with some exploratory transformations to access corresponding differently functionalized tetrasubstituted [2.2]paracyclophane derivatives.
Synthesis, chiral resolution, and absolute configuration of dissymmetric 4,15-difunctionalized [2.2]paracyclophanes
Meyer-Eppler, Georg,Sure, Rebecca,Schneider, Andreas,Schnakenburg, Gregor,Grimme, Stefan,Lützen, Arne
, p. 6679 - 6687 (2014/08/05)
Despite the fact that functionalized planar chiral [2.2]paracyclophanes have received a lot of attention, the chemistry of pseudo-meta 4,15-distubstituted [2.2]paracyclophanes is largely unexplored. This is mainly due to the fact that the 4,5-dibromo-functionalized [2.2]paracyclophane is much less prone to halogen-metal exchange reactions than its constitutional pseudo-ortho or pseudo-para isomers. Here, we give an account of an efficient protocol to achieve this, which allows the synthesis of a broad variety of 4,15-disubstituted [2.2]paracyclophanes. Furthermore, we were able to resolve several of the racemic compounds via chiral HPLC and assign the absolute configurations of the isolated enantiomers by X-ray diffraction and/or by the comparison of calculated and measured CD-spectra.
Cyclophanes. Part LII: Ethynyl[2.2]paracyclophanes - New building blocks for molecular scaffolding
Bondarenko, Lidija,Dix, Ina,Hinrichs, Heino,Hopf, Henning
, p. 2751 - 2759 (2007/10/03)
The synthesis of seven ethynyl[2.2]paracyclophanes is described. The five diethynyl derivatives 4,5-diethynyl[2.2]paracyclophane (12), pseudo-gem-(13), pseudo-ortho-(14), pseudo-meta-(15), and pseudo-para-diethynyl[2.2] paracyclophane (16), the tetraethynyl compound 4,7,13,16-tetraethynyl[2.2] paracyclophane (17), and for comparison the mono-ethynylated hydrocarbon 4-ethynyl[2.2]paracyclophane (11) have been prepared. The structures of these new building blocks for carbon rich systems were determined by the usual analytical and spectroscopic methods.