Sequence‐Controlled Catalytic One‐Pot Synthesis of Siloxane Oligomers

• Published in: Chemistry : a European journal 2019-01, Vol.25 (4), p.920-928
• Main Authors: Matsumoto, Kazuhiro, Shimada, Shigeru, Sato, Kazuhiko
• Format: Article
• Language: English
• Subjects: Alkoxysilanes; boron; Carbonyl compounds; Carbonyls; Catalysis; Chemical synthesis; Chemistry; controlled iteration; homogeneous catalysis; Hydrosilylation; Oligomers; one-pot synthesis; Physicochemical properties; Silicon; Silicones; Siloxanes
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201803565

Silicones are highly valuable poly‐ and oligomeric materials with a broad range of applications due to their outstanding physicochemical properties. The core framework of silicone materials consists of siloxane (Si−O−Si) bonds, and thus, the development of efficient siloxane‐bond‐forming reactions has attracted much attention. However, these reactions, especially “catalytic” siloxane‐bond‐forming reactions that enable the selective formation of unsymmetrical siloxane bonds, remain relatively underdeveloped. On the other hand, controlled iteration has become a powerful tool for the sequence‐controlled synthesis of poly‐ and oligomeric compounds. Recently, control over the siloxane sequence has been achieved by the one‐pot iteration of a B(C6F5)3‐catalyzed dehydrocarbonative cross‐coupling of alkoxysilanes with hydrosilanes and a B(C6F5)3‐catalyzed hydrosilylation of carbonyl compounds. Thus, it is now possible to generate linear, branched, and cyclic sequence‐specific oligosiloxanes in a highly selective manner under chloride‐free conditions. One after another: The one‐pot, controlled iteration of B(C6F5)3‐catalyzed dehydrocarbonative cross‐coupling reactions between alkoxysilanes and hydrosilanes (Piers–Rubinsztajn reaction), and B(C6F5)3‐catalyzed hydrosilylations of carbonyl compounds permits the sequence‐controlled synthesis of linear, branched, and cyclic oligosiloxanes.