Modulating confinement space in metal-organic frameworks enables highly selective indole C3-formylation

Area of Science:

• Organic Chemistry
• Materials Science
• Catalysis

Background:

• Indole derivatives are crucial in pharmaceuticals and materials science.
• Selective functionalization of indoles, particularly at the C3 position, remains a synthetic challenge.
• Existing methods often require harsh conditions or yield mixtures of products.

Purpose of the Study:

• To develop a mild and selective method for C3-formylation of indole.
• To investigate the role of metal-organic frameworks (MOFs) in controlling reaction pathways.
• To utilize the unique properties of MOFs for enhanced catalytic performance.

Main Methods:

• Utilized a metal-organic framework (MOF) as a heterogeneous catalyst.
• Performed selective C3-formylation of indole under mild reaction conditions.
• Employed Density Functional Theory (DFT) calculations to elucidate the reaction mechanism and pore confinement effects.

Main Results:

• Achieved high selectivity for C3-formylation of indole.
• Demonstrated that the confined space within MOF pores suppresses undesired side reactions.
• Observed enhanced formation of the targeted formylated indole product.
• DFT calculations confirmed the experimental findings regarding reaction pathway control.

Conclusions:

• Metal-organic framework (MOF) catalysis offers a promising strategy for selective indole functionalization.
• The pore environment of MOFs can effectively control reactivity and suppress side reactions.
• This work provides a mild and efficient method for synthesizing valuable indole derivatives.