Mild and Efficient Cs₂CO₃-Promoted Synthesis of Silyl Carbonates and Silyl Carbamates

Phillip Gray III, Colby Lavigne, Ralph Salvatore

Southeastern University, University of South Florida

Silyl carbamates and carbonates are ubiquitous compounds that hold a wide array of use as pesticides, serve as novel protecting groups, and possess interesting medicinal applications as peptidomimetics. Their biological applications include an introduction into partial structures of drugs to improve their efficiencies. A novel phosgene-free method and environmentally benign synthesis of silyl carbonates and silyl carbamates were developed via a three-component coupling of an amine or alcohol, carbon dioxide, and a trialkyl or trialkylsilyl halide. Cesium carbonate promoted not only successful carbonylations of alcohols and carbamations of amines, but also suppressed common side reactions traditionally seen using existing protocols. Various alcohols and amines were examined, using a wide array of trialkyl-, triaryl halides, or sulfonates, respectively. In the future, a solid phase synthesis of the title compounds will also be investigated. Applications of this methodology will be applied toward the synthesis of silanediol peptidomimetics