The design of cone-fixed calix[4]arene analogs by takingsyn-[2.n]metacyclophanes as a building block

A facile and efficient route to one-pot synthesis of new cyclophanes using vinamidinium salts

In this study, an efficient method for the synthesis of new cyclophanes (5a–f, 6a–g) through the condensation of 1,4-phenylenedimethanamine (3) or 2,3,5,6-tetramethylbenzene-1,4-diamine (4) with 2-substituted vinamidiniums (2a–g) is described. The cyclophane derivatives are obtained in good to excellent yields in the presence of acetic acid in refluxing acetonitrile after 15 h. The structure of new compounds was validated based on their spectral data (¹H NMR, ¹³C NMR, IR) and elemental analysis.

New cyclophane derivatives are synthesized from the reaction of γ-substituted vinamidinium salts with 1,4-phenylenedimethanamine and 2,3,5,6-tetramethylbenzene-1,4-diamine in the presence of acetic acid and acetonitrile as solvent.

Selected synthetic strategies to cyclophanes

In this review we cover various approaches to meta- and paracyclophanes involving popular reactions. Generally, we have included a strategy where the reaction was used for assembling the cyclophane skeleton for further functionalization. In several instances, after the cyclophane is made several popular reactions are used and these are not covered here. We included various natural products related to cyclophanes. To keep the length of the review at a manageable level the literature related to orthocyclophanes was not included.

Stereocontrol in cyclophane synthesis: a photochemical method to overlap aromatic rings

To overlap aromatic rings in cyclophanes, the inter- and intramolecular [2 + 2] photocycloaddition of vinylarenes has been developed. It gives cyclophanes, naphthalenophanes, phenanthrenophanes, thiophenophanes, and carbazolophanes in reasonable to excellent yields. The structures and properties of cyclophanes obtained are reviewed; especially the excimer emission of phenanthrenophanes, naphthalenophanes, and carbazolophanes stressed that many intriguing cyclophanes can be obtained through the fine molecular design of precursors.