Domino Michael/Michael reaction catalyzed by switchable modularly designed organocatalysts

Area of Science:

• Organic Chemistry
• Catalysis
• Synthetic Methodology

Background:

• Domino reactions offer efficient synthetic routes by performing multiple transformations sequentially in one pot.
• Organocatalysis provides a metal-free approach to catalysis, aligning with green chemistry principles.
• Modularly designed organocatalysts (MDOs) allow for fine-tuning of catalytic activity and selectivity.

Purpose of the Study:

• To investigate the domino Michael/Michael reaction between (E)-7-aryl-7-oxohept-5-enals and trans-cinnamaldehydes.
• To explore the switchable enamine and iminium catalytic modes of MDOs in this reaction.
• To achieve good yields and stereoselectivities for the domino reaction products through catalyst and condition optimization.

Main Methods:

• Utilized modularly designed organocatalysts (MDOs) for the domino reaction.
• Investigated the switchable nature of enamine and iminium catalytic pathways within the MDOs.
• Systematically varied precatalyst modules and reaction conditions to optimize the process.

Main Results:

• Demonstrated that both enamine and iminium catalytic modes of MDOs are switchable.
• Showed that these modes can be individually controlled (switched on/off) by selecting appropriate precatalyst modules and reaction conditions.
• Achieved good yields and stereoselectivities for the domino reaction products when both catalytic modes were active under optimized conditions.

Conclusions:

• MDOs offer a versatile platform for controlling domino Michael/Michael reactions.
• The ability to switch between enamine and iminium catalysis provides precise control over the reaction pathway.
• This work enables efficient and stereoselective synthesis of complex molecules via domino reactions.