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Efficient Synthesis of Polyfunctionalized Benzenes in Water via Persulfate-promoted Benzannulation of α,β-Unsaturated Compounds and Alkynes
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Reductive Deamination with Hydrosilanes Catalyzed by B(C6 F5 )3
Huaquan Fang1, Martin Oestreich1
1Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany.
Angewandte Chemie (International Ed. in English)
|April 21, 2020
Summary
Tris(pentafluorophenyl)borane, a boron Lewis acid, catalyzes amine and hydrosilane coupling. At higher temperatures, this reaction enables transition-metal-free reductive deamination of amines and heterocumulenes.
Area of Science:
- Organometallic Chemistry
- Catalysis
- Organic Synthesis
Background:
- Tris(pentafluorophenyl)borane (B(C6F5)3) is a strong boron Lewis acid.
- It catalyzes dehydrogenative coupling of amines and hydrosilanes at elevated temperatures.
- High temperatures can lead to competing C-N bond cleavage and defunctionalization.
Purpose of the Study:
- To explore the use of B(C6F5)3 for reductive deamination.
- To develop a transition-metal-free methodology for amine and heterocumulene functionalization.
Main Methods:
- Utilizing B(C6F5)3 as a catalyst.
- Employing elevated temperatures to control reaction pathways.
- Investigating the reaction with various amines, isocyanates, and isothiocyanates.
Main Results:
- The competing C-N bond cleavage at higher temperatures was harnessed.
- A novel transition-metal-free reductive deamination of amines was achieved.
- Successful deamination of heterocumulenes like isocyanates and isothiocyanates was demonstrated.
Conclusions:
- B(C6F5)3 can be employed for the reductive deamination of amines and heterocumulenes.
- This method offers a transition-metal-free alternative for defunctionalization reactions.
- The Lewis acid's ability to promote C-N bond cleavage is key to this methodology.
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