A two-step access to fused-/spiro-polycyclic frameworks via double Heck cascade and acid-driven processes

Area of Science:

• Organic Chemistry
• Synthetic Chemistry
• Materials Science

Background:

• Polycyclic frameworks are crucial structural motifs in medicinal chemistry and materials science.
• Developing efficient synthetic routes to complex polycyclic compounds remains a significant challenge in organic chemistry.

Purpose of the Study:

• To rapidly construct two distinct classes of polycyclic frameworks: benzo[a]fluorenones and spiro-chromenone indenes.
• To explore a broad substrate scope for the developed synthetic strategy.
• To investigate the photophysical properties of the synthesized benzo[a]fluorenones.

Main Methods:

• A double Heck cascade reaction was employed for the synthesis of benzo[a]fluorenones.
• An acid-driven cyclization strategy was utilized for the synthesis of spiro-chromenone indenes.
• Alkyl 2-bromocinnamate esters and diphenylacetylenes served as readily accessible starting materials.

Main Results:

• The study successfully synthesized diverse benzo[a]fluorenones and spiro-chromenone indenes with interesting structural features.
• A broad substrate scope was demonstrated, highlighting the versatility of the synthetic methods.
• Fluorescence studies were conducted on the synthesized benzo[a]fluorenones, revealing their photophysical properties.

Conclusions:

• The developed synthetic strategy offers a rapid and efficient route to complex polycyclic frameworks.
• The synthesized compounds possess unique structural characteristics and interesting fluorescence properties.
• This work provides valuable methodologies for accessing novel organic materials.