Selective Electroreductive Hydroboration of Olefins with B₂pin₂

Area of Science:

• Organic Chemistry
• Synthetic Chemistry
• Electrochemistry

Background:

• Organoboron compounds are crucial in synthesizing high-value chemicals.
• Direct hydroboration of olefins is a primary method for organoboron synthesis.
• Existing methods may require metal catalysts or lack broad applicability.

Purpose of the Study:

• To develop a metal-free, electroreductive hydroboration of olefins.
• To synthesize valuable organoboron compounds with high chemo- and regioselectivity.
• To establish a versatile and efficient protocol for organoboron synthesis.

Main Methods:

• Electroreductive anti-Markovnikov hydroboration of olefins.
• Utilized bis(pinacolato)diboron (B2pin2) as the boron source.
• Conducted reactions under metal catalyst-free conditions.

Main Results:

• Achieved synthesis of valuable organoboron compounds with high efficiency.
• Demonstrated broad substrate scope and good functional-group tolerance on styrenes and heteroaromatic olefins.
• Successfully prepared deuterium borylation products with good deuterium incorporation using CD3CN as solvent.
• Validated the method through gram-scale reactions and extensive functional derivatization.

Conclusions:

• The developed electroreductive hydroboration protocol is a powerful metal-free method for synthesizing organoboron compounds.
• This approach offers high chemo- and regioselectivity, broad substrate scope, and functional group tolerance.
• The method shows significant potential for practical applications in organic synthesis and deuterium labeling.