Covalent Template-Guided Synthesis of endo-Functionalized Oligophenylene Cages

Area of Science:

• Organic Chemistry
• Supramolecular Chemistry
• Materials Science

Background:

• Oligophenylene cages are complex molecular architectures with potential applications in host-guest chemistry.
• Efficient synthesis of precisely functionalized cages remains a challenge.

Purpose of the Study:

• To develop an efficient covalent template-guided synthesis for lantern-shaped endo-functionalized oligophenylene cages.
• To investigate the role of covalent templates in promoting intermolecular coupling reactions.

Main Methods:

• Suzuki-Miyaura cross-coupling reactions were employed for cage construction.
• Covalent templates were utilized to direct intermolecular 6-fold coupling.
• Template removal was achieved quantitatively to yield functionalized cages.
• Electrospray ionization mass spectrometry (ESI-MS) was used to monitor reaction mechanisms.

Main Results:

• Lantern-shaped cages were synthesized with high yields (68% and 36%) using covalent templates.
• Template-free synthesis resulted in significantly lower yields (7% and 1%).
• The synthesized OH- and NH2-functionalized cages successfully encapsulated guest molecules (l-TrpOMe and diphenyl phosphate).

Conclusions:

• Covalent template-guided synthesis offers a highly efficient route to functionalized oligophenylene cages.
• The developed method allows for precise control over cage formation and functionalization.
• These cages demonstrate potential for selective molecular encapsulation through host-guest interactions.