Department of Chemistry Seminar - Efficient and General Access to Silylboranes: A Gateway to Iterative Oligosilane Synthesis

Speaker: Professor Hajime ITO

Institution: Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido, Japan

Hosted By: Professor Yangjian QUAN

Abstract

Organosilanes have fascinated researchers for over 150 years due to their unique structural and electronic properties, establishing themselves as indispensable materials in both academia and industry. While oligosilanes containing multiple Si–Si bonds are often accessible via straightforward syntheses, the construction of more complex oligosilanes typically requires laborious, tailor-made synthetic routes. In this presentation, I will introduce an iterative strategy for oligosilane synthesis that employs methoxyphenyl- or hydrogen-substituted silylboronates, which are synthesized via transition-metal-catalyzed Si–H borylation.1,2) The central transformation is a cross Si–Si bond-forming reaction between chloro(oligo)silanes and silylboronates, promoted by methyllithium (MeLi). This is followed by a key chlorination step, which selectively activates either the methoxyphenyl group or the terminal hydrogen atom on the oligosilane framework. By repeating this sequence of bond formation and chlorination, structurally diverse and functionally complex oligosilanes can be efficiently constructed. This methodology enables access to a broad array of oligosilanes that are otherwise difficult to synthesize. Applications toward the synthesis of advanced and functionalized oligosilanes will also be discussed.