Bismuth Subnitrate-Catalyzed Markovnikov-Type Alkyne Hydrations under Batch and Continuous Flow Conditions

Area of Science:

• Organic Chemistry
• Catalysis
• Green Chemistry

Background:

• Alkyne hydration is a key transformation in organic synthesis.
• Developing efficient and sustainable catalytic methods for alkyne hydration remains an important goal.
• Traditional methods often require harsh conditions or toxic reagents.

Purpose of the Study:

• To report bismuth subnitrate as a novel catalyst for Markovnikov-type alkyne hydration.
• To develop both batch and continuous flow processes for methyl ketone synthesis.
• To demonstrate a sustainable and practical approach to alkyne hydration.

Main Methods:

• Utilizing bismuth subnitrate as a heterogeneous catalyst for Markovnikov-type alkyne hydration.
• Performing the reaction in a batch process under mild conditions.
• Developing a continuous flow protocol using a packed-bed system.
• Employing methanol and methanol-d4 as reaction media.

Main Results:

• Bismuth subnitrate effectively catalyzed the atom-economical synthesis of methyl ketones.
• A diverse range of terminal acetylenes were successfully hydrated.
• Trideuteromethyl ketones were synthesized by using methanol-d4.
• The heterogeneous catalyst is readily available, non-toxic, and reusable.

Conclusions:

• Bismuth subnitrate provides a simple, efficient, and sustainable catalytic system for methyl ketone synthesis.
• The developed batch and continuous flow methods offer practical advantages.
• This approach avoids the need for special additives or harmful reagents, enhancing process sustainability.