Functionalization of 3,5,8-trichlorinated BODIPY dyes

Area of Science:

• Organic Chemistry
• Materials Science
• Photochemistry

Background:

• Boron-dipyrromethene (BODIPY) dyes are widely used due to their strong fluorescence and photostability.
• Synthesizing unsymmetrical BODIPY derivatives with controlled substitution patterns remains a synthetic challenge.

Purpose of the Study:

• To develop a versatile synthetic route for creating completely unsymmetrical trisubstituted BODIPY dyes.
• To explore the regioselective functionalization of BODIPY scaffolds via Stille coupling reactions.
• To characterize the structural and photophysical properties of newly synthesized BODIPY compounds.

Main Methods:

• Catalytic hydrogenation and decarboxylative iodination of dipyrroketone precursors.
• Nucleophilic substitution to form trichlorodipyrromethene hydrochloride.
• Lewis acid-mediated cyclization to 3,5,8-trichloro-BODIPY.
• Regioselective and stepwise Stille coupling reactions for introducing diverse substituents.

Main Results:

• A novel synthetic strategy was established for accessing unsymmetrical trisubstituted BODIPYs.
• Regioselective Stille coupling at the 8-position and subsequent couplings at the 3- and 5-positions were achieved.
• Fourteen new BODIPY derivatives were synthesized and characterized, including X-ray crystal structures.
• Photophysical properties of the new BODIPY compounds were systematically investigated.

Conclusions:

• The developed methodology provides efficient access to a wide range of unsymmetrical BODIPY dyes.
• The synthetic route allows for precise control over substituent placement, leading to tunable photophysical properties.
• This work expands the library of BODIPY dyes available for applications in sensing, imaging, and materials science.