Lewis Acid-Base Interaction-Controlled ortho-Selective C-H Borylation of Aryl Sulfides

Area of Science:

• Organometallic Chemistry
• Catalysis
• Organic Synthesis

Background:

• C-H activation and functionalization are crucial in modern organic synthesis.
• Regioselective borylation of aryl sulfides remains a synthetic challenge.
• Developing catalytic methods for directed C-H functionalization is highly desirable.

Purpose of the Study:

• To develop a novel catalytic system for ortho-selective C-H borylation of aryl sulfides.
• To elucidate the mechanism controlling regioselectivity in the C-H borylation reaction.
• To demonstrate the utility of this method for late-stage functionalization of bioactive molecules.

Main Methods:

• Iridium/bipyridine complex as catalyst.
• Lewis acid-base interaction between boryl group and sulfur atom for directing ortho-selectivity.
• Gram-scale synthesis and application to a bioactive molecule.

Main Results:

• Achieved high ortho-selectivity in the C-H borylation of aryl sulfides.
• Established the first catalytic C-H transformation controlled by a ligand-substrate Lewis acid-base interaction.
• Demonstrated gram-scale applicability and successful late-stage functionalization of a bioactive molecule.

Conclusions:

• The developed iridium-catalyzed reaction provides an efficient route for regioselective C-H borylation of aryl sulfides.
• The Lewis acid-base interaction is key to achieving high ortho-selectivity.
• The method is suitable for late-stage functionalization and synthesis of complex molecules, including bioactive compounds.