This project tackles the problem of activation of main group substrates and their transformation into useful products. This field is virtually unexplored and the work to date has focused on expensive transition metal catalysts which can lead to toxic residues. Main group molecules and materials are of widespread interest as a result of their useful combination of physical and chemical properties, which offer exciting opportunities for their use as synthetic reagents and advanced materials for many different applications. For example, they have societal uses as fire retardants, elastomers, LEDs, ceramic precursors, and as reagents in organic synthesis. As silicon is the earth’s second most abundant element, compounds containing silicon have much potential because of their lower price. Traditionally, silylphosphanes have been prepared by the reaction of chlorosilanes with alkali metal phosphanides, a process that generates at least one equivalent of salt waste and has limited functional group tolerance. The production of salt waste will cause the erosion of reactors and thus limit its bulk production and also not economic. As part of the Marie Curie project we have developed a new catalytic dehydrocoupling method to prepare E-E' bonds using a metal-free borane as the catalyst. This process only produces H2 as a side product, the hydrogen gas is easy to separate from the reaction product and it can also be used as energy source. The work has been published in the top high-impact journal J. Am. Chem. Soc. and creates a new and convenient method for making silylphosphines which are highly deserable organic substrates.
The project is important for society because with the new catalytic route there are no wasteful byproducts and the process also does not involve the use of toxic and expensive transition metals like most current catalytic processes. The new route to silylphosphines provides a prototype example of how main group substrates can be converted into useful products.
The overall long term objective is to harness main group substrates based on abundant elements such as silicon and phosphorus as precursors to a wide variety of useful products, both molecular and polymeric.
Furthermore, the skills learned during the project enabled Dr. Wu to return to his homeland, China, with a faculty position in Lanzhou institute of Chemical Physics and to obtain a prestigious “1000 talents” award.
