Efficient synthesis of (P-chirogenic) o-boronated phosphines from sec-phosphine boranes

Area of Science:

• Organic Chemistry
• Organophosphorus Chemistry
• Boron Chemistry

Background:

• Phosphine ligands are crucial in catalysis.
• Developing novel synthetic routes for functionalized phosphines is important.
• Boronated organic compounds have diverse applications.

Purpose of the Study:

• To report an efficient synthesis of boronated phosphines.
• To utilize benzyne chemistry for constructing o-phenylene-bridged boronated phosphines.
• To investigate stereochemical outcomes in the synthesis.

Main Methods:

• Synthesis of sec-phosphine boranes.
• Benzyne generation from 1,2-dibromobenzene.
• Reaction with organolithium reagents and boron sources.
• Decomplexation and trifluoroboration.

Main Results:

• Efficient synthesis of o-boronatophenylphosphine derivatives achieved in 71% yield.
• Retention of configuration at the phosphorus center from P-chirogenic precursors.
• High enantiomeric excess (>98%) for the final trifluoroborated phosphine.

Conclusions:

• A novel and efficient route to boronated phosphines has been established.
• The developed method allows for stereoselective synthesis of valuable organophosphorus compounds.
• The resulting boronated phosphines are suitable for further functionalization.