Synthesis of Multisubstituted Heterocyclic and Aromatic Compounds Using Catalyst-Controlled Site-Selective Reactions.

Area of Science:

• Organic Chemistry
• Catalysis
• Synthetic Methodology

Background:

• Site-selective reactions are crucial for synthesizing complex molecules, but selectivity is often substrate-dependent.
• Existing methods limit the scope of reactions due to substrate control over selectivity.
• Catalyst-controlled reactions offer greater versatility, with ligand design being a key factor.

Purpose of the Study:

• To develop novel ligands for catalyst-controlled site-selective reactions.
• To enable the synthesis of multisubstituted compounds, including pharmaceuticals and functional molecules.
• To overcome limitations of substrate-controlled selectivity in organic synthesis.

Main Methods:

• Development of hydroxyterphenylphosphine ligands for palladium catalysis.
• Application in ortho-selective Sonogashira coupling/cyclization/Suzuki-Miyaura coupling protocols.
• Catalyst-controlled C3-selective arylation of N-nonsubstituted indoles and 1H-pyrroles.

Main Results:

• Achieved ortho-selective cross-coupling of dihalogenated phenols/anilines using hydroxyterphenylphosphine ligands.
• Synthesized multisubstituted benzofurans and indoles via a one-pot protocol.
• Enabled direct C3-selective arylation of indoles and regioselective arylation of pyrroles, yielding challenging substitution patterns.

Conclusions:

• The developed palladium catalysts with hydroxyterphenylphosphine ligands offer precise control over reaction site.
• This approach significantly expands the scope of site-selective synthesis for complex organic molecules.
• The methodology provides efficient routes to valuable compounds previously difficult to access.