Substrate- and Reagent-Controlled Dimerization of Vinyl para-Quinone Methides.

Area of Science:

• Organic Chemistry
• Synthetic Chemistry
• Natural Product Synthesis

Background:

• Vinyl para-quinone methides (VPQMs) are reactive intermediates.
• Dimerization reactions are crucial for constructing complex molecular architectures.

Purpose of the Study:

• To investigate substrate and reagent-controlled dimerization of VPQMs.
• To explore divergent reaction pathways leading to distinct dimer structures.

Main Methods:

• Utilized Brønsted acidic conditions for VPQM dimerization.
• Employed optimized Lewis acidic conditions to alter regioselectivity.
• Applied these methods to various complex substrates.

Main Results:

• Achieved formal 1,8-addition under Brønsted acidic conditions, yielding griffipavixanthone (GPX)-type congeners.
• Observed a regioselective change under Lewis acidic conditions, leading to 1,6-addition/cyclization and formation of limonene-containing dimers.
• Synthesized analogues of the natural product GPX and novel substituted limonene dimers.

Conclusions:

• Demonstrated substrate and reagent control over VPQM dimerization.
• Established a divergent synthetic strategy for accessing GPX analogues and novel limonene dimers.
• Highlighted the versatility of VPQMs in complex molecule synthesis.