In a recent paper, Associate Professor Jie WU and his colleagues from the Department of Chemistry, NUS, have developed a new method for synthesising organosilanes, a family of chemical compounds which have a variety of applications from organic and polymer synthesis, materials science, medicinal chemistry, to agriculture. The researchers used eosin Y, a low-cost, readily available dye molecule, as a photocatalyst to selectively remove hydrogen atoms from hydrosilanes. This enables different functional chemical groups to be attached to the silicon atom in a step by step manner, potentially creating a wide variety of useful silicon compounds. An amount of energy of approximately 90 kcal/mol is required to break a Si-H bond, and the uniqueness of this catalyst is that it uses much lower energy (~63 kcal/mol) to break the Si-H bond. Also, unlike other photocatalysts, eosin Y is able to selectively break the Si-H bonds rather than some more reactive C-H bonds. More than eight different new chemical transformations have been realised by the research team using various commodity feedstocks as the starting materials to react with hydrosilanes.
These findings were published in the journal Nature Chemistry.
Prof Wu said, “We would like to establish a general and sustainable strategy to synthesize functional organosilanes in an efficient, on-demand, and fully automated fashion. With this method, the preparation of desired silicon reagents will be more easily accessible, and in future, chemists can focus their energies on the design and development of functional silicon molecules limited only by their imagination.” The figure above illustrates the stepwise decoration of the silicon atom using the RSiH3 molecule in an on-demand and automated manner. In each step, one of the hydrogen atom bonded to the silicon atom is replaced with a functional group. This is achieved by using eosin Y photocatalysis. After three steps, the RSiH3 molecule can have up to four different functional groups attached to the silicon atom. Read the full story here.
