Chalcogen-containing carboranes have been known for several decades and possess stable exopolyhedral B(9)-Se and B(9)-Te σ bonds despite the electron-donating ability of the B(9) vertex. While these molecules are known, little has been done to thoroughly evaluate their electrophilic and nucleophilic behavior. Herein, we report an assessment of the electrophilic reactivity of meta-carboranyl selenyl (II), tellurenyl (II), and tellurenyl (IV) chlorides and establish their reactivity pattern with Grignard reagents, alkenes, alkynes, enolates, and electron-rich arenes. These electrophilic reactions afford unique electron-rich B-Y-C (Y = Se, Te) bonding motifs not commonly found before. Furthermore, we show that meta-carboranyl selenolate, and even meta-carboranyl tellurolate, can be competent nucleophiles and participate in nucleophilic aromatic substitution reactions. Arene substitution chemistry is shown to be further extended to electron-rich species via the palladium mediated cross-coupling chemistry.
- Harrison Mills University of California, Los Angeles ,
- Fadi Alsarhan University of California, Los Angeles ,
- Ta-Chung Ong University of California, Los Angeles ,
- Milan Gembicky University of California, San Diego ,
- Arnold Rheingold University of California, San Diego ,
- Alexander Spokoyny University of California, Los Angeles