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Phosphine-Directed sp3 C-H, C-O, and C-N Borylation
Kelsey C Morris1, Shawn E Wright1, Gillian F Meyer1
1Department of Chemistry and Biochemistry, University of San Diego, 5998 Alcala Park, San Diego, California 92110, United States.
The Journal of Organic Chemistry
|September 18, 2020
Summary
This study expands phosphine-directed C-H borylation to benzylic substrates, achieving high yields of mono- and geminal bis-borylation products. New methods enable selective functionalization of challenging benzylic positions.
Area of Science:
- Organic Chemistry
- Catalysis
- Synthetic Methodology
Background:
- Benzylic C-H borylation is synthetically challenging.
- Existing methods lack efficiency and selectivity for benzylic substrates.
- New catalytic approaches are needed for functionalizing these positions.
Purpose of the Study:
- To develop novel phosphine-directed C-H borylation methods for benzylic substrates.
- To achieve efficient and selective mono- and geminal bis-borylation.
- To explore the reactivity of benzylic ethers and amines under these conditions.
Main Methods:
- Utilized phosphine-directed catalysis for C-H borylation.
- Applied the methodology to various benzylic substrates.
- Investigated reactions involving benzylic ethers and amines.
Main Results:
- Achieved high yields of mono- and geminal bis-borylated products from benzylic substrates.
- Demonstrated successful C-H borylation of arenes and extended it to benzylic positions.
- Observed C-O and C-N borylation followed by C-H borylation in benzylic ethers/amines, yielding geminal bis-borylated products.
Conclusions:
- Phosphine-directed C-H borylation is a versatile method for functionalizing benzylic positions.
- The developed approach offers high yields and selectivity.
- The study expands the scope of C-H borylation to include benzylic ethers and amines.
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