Synthesis of Polysilanes by New Procedures: Part 2 Catalytic Dehydropolymerisation of Hydrosilanes

The Wurtz coupling technique is currently the most useful method for the synthesis of polysilanes. However, it has its drawbacks. It produces a low percentage of useful polymer, the reaction conditions are hazardous and considerable salt waste is generated. One of the more promising alternatives to Wurtz reductive coupling is the use of metallocene based catalysts in dehydrogenative coupling of alkyl and aryl silanes, so called ‘catalytic dehydrocoupling’. The reaction conditions are generally milder than those used for the Wurtz-type coupling and allow the inclusion of functional groups that would not survive exposure to sodium. Control of the polymer molecular weight and, ideally, of stereochemistry, should also be possible with an understanding of the mechanism. Several reviews of the catalytic dehydrogenative coupling of silanes already exist [1] and the purpose of this review is to present an overview of the subject.