Reduced symmetry triflate-resorcin[4]arenes

Copper(I)-Catalyzed Alkyne-Azide Cycloaddition (CuAAC) "Click" Reaction: A Powerful Tool for Functionalizing Polyhydroxylated Platforms

Click chemistry is currently one of the most used tools for the generation of complex organic molecules. The advantages of using click chemistry in organic synthesis are remarkable; in many cases, the reactions occur under mild conditions and are free of solvents, with high yields and short reaction times. This makes it an extraordinarily effective and viable alternative for obtaining complex/conjugated molecules. In this review, the use of click chemistry CuAAC is especially emphasized for polyhydroxylated platforms such as resorcinarenes or calixarenes, focusing mainly on aspects of synthesis, specifically conditions, reagents, and methodologies.

One-Step Synthesis of C2v-Symmetric Resorcin[4]arene Tetraethers

The three-component reaction between a resorcinol, 1,3-dimethoxybenzene, and an alkyl aldehyde (R = C₁-C₁₁) along with BF₃·OEt₂ affords a C_2v-symmetric resorcin[4]arene tetraether in one step; in most cases, the single isomer can be precipitated from the reaction mixture in moderate to excellent yields (up to 89%). The reaction is tolerant of 2-substituted resorcinols (R' = OH, Cl, Br, Me), allowing a third type of functionality to be regioselectively incorporated during the macrocyclization.

Rigid tetraarylene-bridged cavitands from reduced-symmetry resorcin[4]arene derivatives

Two tetraaryl-extended macrocycles were prepared from resorcin[4]arenes. The C_2v-symmetric isomer afforded a new rigid cyclooctaphenylene cavitand following oxidative cyclodehydrogenation.