Expeditious Access to the B₃NO₂ Heterocycle Enabling Modular Derivatization

Area of Science:

• Organic Chemistry
• Catalysis
• Heterocyclic Chemistry

Background:

• 1,3-dioxa-5-aza-2,4,6-triborinane (DATB) is a six-membered heterocycle.
• DATB exhibits catalytic activity in direct dehydrative amidation reactions.
• Efficient synthesis of DATB derivatives is crucial for exploring their catalytic potential.

Purpose of the Study:

• To report an improved and concise synthetic protocol for DATB derivatives.
• To develop a chromatography-free method for DATB synthesis.
• To enable the preparation of diverse DATB derivatives.

Main Methods:

• A two-step synthesis was employed.
• Suzuki-Miyaura coupling was used to link 2,6-dibromoaniline derivatives with 1,2-phenylenediboronic acid, forming dimeric B-spiroborate salts.
• Acidic treatment of the spiroborates yielded the DATB ring system.

Main Results:

• A concise, two-step, chromatography-free synthetic protocol for DATB derivatives was established.
• The method successfully produced DATB ring systems with various substituents.
• Dimeric B-spiroborate salts were synthesized as key intermediates.

Conclusions:

• The developed synthetic route offers an efficient and practical approach to DATB derivatives.
• This improved synthesis facilitates further investigation into the catalytic applications of DATB compounds.
• The chromatography-free nature of the process enhances its utility for broader chemical synthesis.