Linker-Controlled Macrocyclizations Enabling Selective Formation of Cyclic Trimers via Si-O Bond Formations

Area of Science:

• Organic Chemistry
• Macromolecular Science
• Synthetic Chemistry

Background:

• Silicon-oxygen (Si-O) bond-forming macrocyclization is a key method for creating precise macrocyclic structures.
• Previous methods using Ar-O-Si-O-Ar systems predominantly yielded cyclic tetramers.

Purpose of the Study:

• To investigate the impact of diol linker structure modification on Si-O macrocyclization outcomes.
• To explore the selective synthesis of different macrocyclic ring sizes.

Main Methods:

• Synthesized novel diol linkers with incorporated methylene spacers.
• Performed Si-O bond-forming macrocyclization reactions using modified linkers.
• Analyzed the resulting macrocyclic products for yield and structural integrity.

Main Results:

• Modification of the diol linker structure reversed the selectivity from cyclic tetramers to cyclic trimers.
• High yields of silyl ether cyclic trimers were achieved, even under concentrated reaction conditions.
• Demonstrated effective control over macrocycle size through rational linker design.

Conclusions:

• The outcome of Si-O macrocyclization is highly sensitive to linker architecture.
• Rational design of linkers provides a powerful strategy for tuning the selectivity of macrocyclization.
• This work expands the synthetic utility of Si-O bond-forming reactions for precise macrocycle construction.