Catalytic Access to Diastereometrically Pure Four- and Five-Membered Silyl-Heterocycles Using Transborylation
Dominic R Willcox1, Emanuele Cocco1,2, Gary S Nichol1
1EaStCHEM School of Chemistry, University of Edinburgh, David Brewster Road, EH9 3FJ, Edinburgh, United Kingdom.
Angewandte Chemie (International Ed. in English)
|April 5, 2024
Summary
A new catalytic method enables the synthesis of functionalized silyl-heterocycles using borane-catalyzed intramolecular carboboration of silyl-alkynes. This approach expands chemical space for diverse applications.
Area of Science:
- Organic Chemistry
- Organosilicon Chemistry
- Catalysis
Background:
- Silyl-heterocycles are valuable building blocks for expanding chemical space.
- Limited catalytic methods hinder the synthesis of diverse and functionalized silyl-heterocycles.
Purpose of the Study:
- To develop a catalytic method for the synthesis of silyl-heterocycles.
- To enable the preparation of diverse and functionalized 2,3-dihydrosilolyl and silylcyclobut-2-enyl boronic esters.
Main Methods:
- Borane-catalyzed intramolecular 1,1-carboboration of silyl-alkynes.
- Utilized transborylation-enabled turnover for catalytic efficiency.
- Employed mechanistic studies including 13C-labeling and computational analysis.
Main Results:
- Successfully synthesized various functionalized silyl-heterocycles via catalytic carboboration.
- Demonstrated the formation of 2,3-dihydrosilolyl and silylcyclobut-2-enyl boronic esters.
- Identified a reaction pathway involving 1,2-hydroboration, 1,1-carboboration, and transborylation.
Conclusions:
- Developed a novel borane-catalyzed method for silyl-heterocycle synthesis.
- The catalytic carboboration offers a versatile route to diverse organosilicon compounds.
- Mechanistic insights clarify the reaction pathway and catalyst regeneration.
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