Unsymmetrical diborane(4) derivatives by copper mediated B-B coupling

Area of Science:

• Organoboron chemistry
• Synthetic inorganic chemistry
• Materials science

Background:

• Unsymmetrical diborane(4) derivatives are valuable synthetic intermediates.
• Existing methods for synthesizing these compounds are limited in scope and versatility.
• There is a need for modular and efficient routes to access diverse diborane(4) structures.

Purpose of the Study:

• To develop a novel, versatile, and modular synthetic route to unsymmetrical diborane(4) derivatives.
• To demonstrate the broad applicability of the developed method by synthesizing various diol and diamine substituted compounds.
• To characterize the newly synthesized diborane(4) derivatives using advanced techniques.

Main Methods:

• Utilizing a nucleophilic boron source (copper(I) boryl complexes) and an electrophilic boron source (boron halides).
• Establishing the boron-boron bond through the reaction of these complementary boron species.
• Employing commercially available starting materials for both nucleophilic and electrophilic boron reagents.

Main Results:

• Successfully synthesized seven previously inaccessible unsymmetrical diborane(4) derivatives.
• The synthesized compounds feature diverse combinations of diol and diamine moieties.
• Full characterization, including single crystal X-ray structure determination, confirmed the structure and purity of the products.

Conclusions:

• The presented method offers a versatile and modular approach to unsymmetrical diborane(4) synthesis.
• The reaction's simplicity, relying on nucleophile-electrophile coupling, allows for easy variation of boron substituents.
• This work significantly expands the accessibility of complex diborane(4) derivatives for further research and applications.