Catalytic Undirected Meta-Selective C-H Borylation of Metallocenes.

Area of Science:

• Organometallic Chemistry
• Synthetic Chemistry
• Catalysis

Background:

• Metallocenes are crucial structural motifs in chemistry and materials science.
• Direct C-H functionalization offers a simple route to modify metallocenes.
• Existing C-H functionalization methods struggle with regioselectivity, particularly for 1,3-difunctionalization.

Purpose of the Study:

• To develop an efficient and regioselective method for C-H borylation of metallocenes.
• To enable the synthesis of 1,3-difunctionalized metallocenes and related compounds.
• To demonstrate the broad applicability and synthetic utility of the developed method.

Main Methods:

• Iridium-catalyzed meta-selective C-H borylation reaction.
• Utilized various metallocenes including benzoferrocenes, ferrocenes, and ruthenocene.
• Explored compatibility with diverse functional groups and scalability.

Main Results:

• Achieved efficient meta-selective C-H borylation of metallocenes without directing groups.
• Synthesized a range of boronic esters from benzoferrocenes, ferrocenes, and ruthenocene.
• Demonstrated exclusive borylation on the benzene ring of benzoferrocenes, attributed to steric effects.

Conclusions:

• The developed iridium-catalyzed C-H borylation is a powerful tool for regioselective functionalization of metallocenes.
• The method offers broad functional group tolerance and scalability for synthesizing valuable organoboron compounds.
• The synthesized boronic esters serve as versatile intermediates for further chemical transformations.