Synthesis of Functionalized Resorcin[4]arene via Click Chemistry

Click chemistry is a very powerful chemical strategy that overcome carbon-carbon bond with carbon-heteroatom bond by joining small units with heteroatom links (C-X-C) using spring-loaded reactants. The Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition is a major example based on the click chemistry philosophy. This method was used for the last 10 years to join different functional groups, carbohydrates, aminoacids, polymers to calix[4]arene and resorcin[4]arene cavitands by a stable 1,2,3-triazole linkages. Herein I describe our interest in this type of click chemistry reaction in the synthesis of dimeric capsules resorcin[4]arene via four 1,2,3-triazole linkages. Two different resorcin[4]arene derivatives were synthesized in which four azide and four alkyne functional groups were attached on the upper rim of two different resorcin[4]arenes. The dimerization reaction was quite challenging due to steric factors. Each resorcin[4]arene derivative was then studied individually via click chemistry and all click reaction results were excellent and the products were isolated in good yields. These results enhanced the synthesis of the dimeric resorcin[4]arene