Boron-Enabled Stereoselective Synthesis of Polysubstituted Housanes

Area of Science:

• Organic Chemistry
• Medicinal Chemistry
• Catalysis

Background:

• Designing novel molecular scaffolds with defined exit vectors is key to expanding drug-like chemical space.
• Polysubstituted housanes offer unique three-dimensional structures for medicinal chemistry applications.

Purpose of the Study:

• To develop an efficient boron-enabled strategy for synthesizing polysubstituted housanes from nonsymmetrical dienes.
• To establish housanes as versatile, derivatizable scaffolds for exploring three-dimensional chemical space.

Main Methods:

• Utilizing a geminal diboron system for site-, regio-, and diastereoselective energy transfer-catalyzed [2 + 2] cycloaddition of dienes.
• Employing a cyclobutyl anion intermediate for stereospecific intramolecular annulation.
• Conducting mechanistic and density functional theory (DFT) studies.

Main Results:

• A two-step synthesis of complex housanes with three defined exit vectors was achieved.
• High site-, regio-, and diastereoselectivity was observed in the cycloaddition step.
• Systematic derivatization demonstrated broad chemical diversification potential.
• DFT studies elucidated the stereoelectronic factors governing selectivity and reactivity.

Conclusions:

• Housanes are stable, rigid molecular fragments with multidirectional exit vectors.
• The developed boron-enabled strategy provides a powerful platform for 3D chemical space exploration in drug discovery.
• This method facilitates the efficient synthesis of complex molecular architectures for medicinal chemistry.