Multiple Cycloadditive Macrocyclization: An Efficient Method for Crown Ether-Type Cyclophanes, Bis-Calix[4]arenes and Silamacrocycles

Macrocycles constitute a broad spectrum of compounds, which play a significant role in host-guest supramolecular chemistry. We have rationally designed an efficient novel synthetic method to synthesize different types of artificial receptive macrocycles containing isoxazoline or isoxazole ring systems. This method involves multiple (double, triple or quadruple) cycloadditions between bifunctional dipoles and bifunctional dipolarophiles. We have presented our synthetic results to show the ease with which this one-pot synthetic method can be extended to synthesize different types of macrocycles such as cyclophanes, bis-calix[4]arenes and silamacrocycles. Hence, with appropriate combination of bifunctional dipoles and bifunctional dipolarophiles, the ring size of macrocycles could be controlled. This multiple cycloadditive macrocyclization will be a useful arsenal for the synthesis of various macrocycles.