Modular Synthesis of New Metalloid-Substituted Olefins from Diboryl(Silyl)Ethenes via Suzuki-Miyaura Reactions

A novel approach towards synthesizing new metalloid-substituted olefins has been accomplished by transforming (E)-1,2-diboryl-1-silylethenes through two consecutive Suzuki-Miyaura coupling reactions. This methodology provides an effective and selective way to obtain new, structurally different products, such as (E)-1-silyl-1-boryl-2-arylethens, (1E,3E)-1-silyl-1-boryl-2-alkenylethens, and (E)-1-silyl-1-aryl₁-2-aryl₂ethenes, which are difficult to synthesize through hydrometallation reactions and related processes. Due to the presence of reactive motifs (silyl group, Bpin moiety, and C_sp2-H bond) in the structure of the final products, these molecules might be considered powerful building blocks in modern chemistry. With the aid of demetallation and cross-coupling reactions, they might be further functionalized into several invaluable chemicals, i.e., tetrasubstituted olefins (anti-cancer drugs, fluorescence materials), compounds with high π-conjugation, and polymers.