Acyl silane directed Cp*Rh(III)-catalysed alkylation/annulation reactions.

Area of Science:

• Organometallic Chemistry
• Organic Synthesis
• Catalysis

Background:

• Rhodium(III)-catalyzed C-H functionalization is a powerful synthetic tool.
• Aryl acyl silanes have emerged as versatile building blocks in organic synthesis.
• Directing group strategies are crucial for regioselective C-H activation.

Purpose of the Study:

• To develop a novel synthetic strategy for silicon-derived indene frameworks.
• To explore the utility of aryl acyl silanes in rhodium-catalyzed reactions.
• To investigate intramolecular aldol condensation as a key reaction pathway.

Main Methods:

• Cp*Rh(iii)-catalyzed hydroarylation of alkenes with aryl acyl silanes.
• Analysis of reaction intermediates and products using spectroscopic methods.
• Extension of the methodology to synthesize silicon-derived benzofurans.

Main Results:

• A new synthetic route to 2-formyl- and 2-acetyl-3-silyl indenes was established.
• The reaction proceeds via intramolecular aldol condensation, not protodemetalation.
• This is the second reported instance of rhodium-catalyzed C-H functionalization using acyl silanes as directing groups.
• The strategy was successfully applied to synthesize analogous silicon-derived benzofurans.

Conclusions:

• Cp*Rh(iii)-catalysis enables a novel intramolecular aldol condensation pathway with aryl acyl silanes.
• This methodology provides efficient access to unique silicon-containing indene and benzofuran scaffolds.
• The study expands the scope of rhodium-catalyzed C-H functionalization and acyl silane chemistry.