Four-Component Strain-Release-Driven Synthesis of Functionalized Azetidines

Area of Science:

• Organic Chemistry
• Medicinal Chemistry
• Synthetic Chemistry

Background:

• Azetidine rings are valuable scaffolds in drug discovery, but efficient synthetic methods are lacking.
• Developing diversity-oriented synthesis strategies for azetidines is crucial for drug development.

Purpose of the Study:

• To develop a novel and efficient method for the modular synthesis of substituted azetidines.
• To apply this methodology for the rapid generation of diverse azetidine-based compound libraries.

Main Methods:

• A multicomponent reaction involving a [1,2]-Brook rearrangement and a strain-release driven anion relay sequence.
• Sequential addition of three distinct electrophilic coupling partners to an azabicyclo[1.1.0]butane-derived organolithium intermediate.
• In situ infra-red spectroscopy was used to monitor reaction kinetics.

Main Results:

• Successful realization of the multicomponent reaction for azetidine synthesis.
• Demonstrated modularity by varying three electrophilic coupling partners to access diverse structures.
• Achieved rapid synthesis driven by the strain-release ring-opening of azabicyclo[1.1.0]butane.
• The methodology was applied to a 4-step synthesis of the EP2 receptor antagonist PF-04418948.

Conclusions:

• The developed method provides a rapid, modular, and diversity-oriented approach to substituted azetidines.
• This strategy significantly advances the synthetic accessibility of azetidine-containing molecules for drug discovery.
• The synthesis of PF-04418948 highlights the practical utility of this novel methodology.