Copper-Catalyzed [1,3]-Dipolar Cycloaddition for the Synthesis of Macrocycles Containing Acyclic, Aromatic and Steroidal Moieties

Copper-catalyzed 1,3-dipolar cycloaddition reactions are used for the synthesis of a series of bis(1,2,3-triazole)-containing macrocycles possessing acyclic, aromatic and steroidal fragments. The influence of the nature of the substituents on the diazides, and the length of the dialkyne-linking chain, in the substrates, on the product yields is studied. Macrocycles containing steroidal fragments are prepared via reactions of bis(cholane)-24,24'-diazides with aliphatic dipropargyl esters, or bis(cholane)-24,24'-dipropargyl esters with aromatic diazides, or by cyclization-dimerization of bile acid derivatives possessing both azide and acetylene groups in the same molecule.