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Diazoborane-Promoted Boron Insertion into Olefinic C-H Bonds
Chonghe Zhang1, Christopher C Cummins1, Robert J Gilliard1
1Department of Chemistry, Massachusetts Institute of Technology, Cambridge02139, Massachusetts, United States.
Journal of the American Chemical Society
|July 22, 2026
Summary
Researchers developed a new borylation method using diazoboranes. This novel reaction inserts boron into olefinic C-H bonds, offering a versatile synthetic strategy for organoboron compounds.
Area of Science:
- Synthetic Chemistry
- Organometallic Chemistry
- Catalysis
Background:
- Organoboron compounds are crucial intermediates in organic synthesis.
- Development of novel borylation strategies is essential for accessing diverse organoboron compounds.
- Existing methods often involve addition to unsaturated bonds or substitution reactions.
Purpose of the Study:
- To report a novel borylation reaction mediated by diazoboranes.
- To investigate the mechanism and scope of this new C-H borylation method.
- To explore the stereochemical outcomes of the reaction.
Main Methods:
- Utilized diazoboranes (RLBN2) as borylene precursors.
- Investigated the reaction with a broad range of olefinic substrates.
- Performed detailed mechanistic studies including stereochemical analysis.
Main Results:
- Diazoboranes mediate net insertion into olefinic C-H bonds.
- The reaction exhibits broad substrate scope, including various substituted olefins.
- High stereoselectivity for the E isomer was observed in most cases, with notable exceptions like acrylonitrile yielding the Z isomer.
Conclusions:
- Diazoborane-mediated C-H borylation represents a new and versatile synthetic approach.
- The stereochemical outcome is governed by a balance of orbital interactions and steric effects.
- This method expands the toolkit for synthesizing functional organoboron compounds.
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