Fluorous dimethyl sulfide: a convenient, odorless, recyclable borane carrier.

Area of Science:

• Organic Chemistry
• Green Chemistry
• Catalysis

Background:

• Borane reagents are essential in organic synthesis for hydroboration and reduction reactions.
• Handling volatile and reactive borane gas presents challenges in laboratory settings.
• Development of recyclable and easily separable reagents is crucial for sustainable chemistry.

Purpose of the Study:

• To develop a stable and recyclable borane reagent for hydroboration and reduction reactions.
• To investigate the efficiency of the fluorous borane sulfide (fluorous BMS) in organic transformations.
• To demonstrate the application of fluorous BMS in asymmetric synthesis and reduction of various functional groups.

Main Methods:

• Formation of a solid 1:1 mixture of borane gas and 2-(perfluorooctyl)ethyl methyl sulfide (fluorous BMS).
• Hydroboration of alkenes using fluorous BMS in a dichloromethane/perfluorinated hydrocarbon solvent system.
• Recycling of the fluorous sulfide component via fluorous extraction.
• Application of fluorous BMS in asymmetric reduction of ketones catalyzed by a chiral oxaborolidine.
• Reduction of other functional groups using the fluorous BMS system.

Main Results:

• Fluorous BMS was successfully synthesized as a stable solid mixture.
• Efficient hydroboration of alkenes was achieved using fluorous BMS.
• The fluorous sulfide could be effectively recycled through fluorous extraction, demonstrating its reusability.
• The system showed utility in asymmetric ketone reduction and reduction of other functional groups.

Conclusions:

• Fluorous BMS offers a practical and recyclable alternative to traditional borane reagents.
• The developed method facilitates greener organic synthesis through reagent recovery and reuse.
• This fluorous approach expands the scope of borane chemistry, particularly in asymmetric reductions.