Three-Component Reaction to 1,4,2-Diazaborole-Type Heteroarene Systems

Area of Science:

• Organoboron Chemistry
• Heterocyclic Chemistry
• Synthetic Methodology

Background:

• Boranes are versatile reagents in organic synthesis.
• Three-component reactions offer efficient pathways to complex molecules.
• Dihydro-1,4,2-diazaboroles are a rare class of heterocyclic compounds.

Purpose of the Study:

• To develop a novel three-component reaction for synthesizing dihydro-1,4,2-diazaborole derivatives.
• To explore the reactivity of these novel heterocyclic compounds.
• To synthesize and characterize related BN-containing heterocycles.

Main Methods:

• Three-component reaction of borane FmesBH2 with isonitriles and organonitriles.
• Reactions of dihydro-1,4,2-diazaboroles with acylating agents and alkynes.
• X-ray diffraction analysis for structural characterization.

Main Results:

• Successful synthesis of rare dihydro-1,4,2-diazaborole derivatives.
• Demonstration of nucleophilic character and 1,3-dipolar reactivity.
• Formation of pyrrole products via [3+2] cycloaddition/[4+2] cycloreversion.
• Synthesis of annulated BN-indolizine and dihydro-1,4,2-oxaza/thiazaborole derivatives.
• Isolation and structural characterization of a heterobicyclo[2.2.1]heptane derivative.

Conclusions:

• The developed three-component reaction provides efficient access to dihydro-1,4,2-diazaboroles.
• These derivatives exhibit diverse and useful reactivity, including acylation and cycloaddition.
• The study expands the scope of BN-heterocycle synthesis and their applications in organic chemistry.