Boradigermaallyl: (4+3) Cycloaddition-Initiated Boron Insertion into Benzene

Area of Science:

• Organometallic Chemistry
• Synthetic Chemistry
• Computational Chemistry

Background:

• The synthesis and reactivity of novel boron-containing compounds are of significant interest in inorganic and organometallic chemistry.
• Allyl cation analogues with unique electronic structures offer potential for new reaction pathways.

Purpose of the Study:

• To synthesize and characterize a 2π electron 1,3-dipole boradigermaallyl.
• To investigate the reactivity of this boradigermaallyl with benzene.
• To elucidate the reaction mechanism using computational methods.

Main Methods:

• Synthesis of the boradigermaallyl from a bis(germylene) precursor.
• Reaction of the boradigermaallyl with benzene at room temperature.
• Computational investigation of the reaction mechanism, including cycloaddition pathways.

Main Results:

• Successful synthesis of the 2π electron 1,3-dipole boradigermaallyl.
• Observation of room-temperature reaction with benzene, involving boron atom insertion.
• Identification of a concerted (4+3) or [π4s+π2s] cycloaddition mechanism.
• Demonstration of boradigermaallyl acting as a reactive dienophile with benzene.

Conclusions:

• The boradigermaallyl exhibits unique reactivity as a dienophile in cycloaddition reactions with arenes.
• This reactivity establishes a new platform for ligand-assisted borylene insertion chemistry.
• The findings expand the scope of organoboron and organometallic chemistry.