Preparation of bromosilane from hydrosilane using brominating agents

Abstract

Two methodologies for the preparation of bromosilane from hydrosilane have been developed. The first system comprising of ethyl tribromoacetate (Br₃ CCOOEt) with a catalytic amount of PdCl₂ at reflux THF, could convert hydrosilane to bromosilane in high yield within 15 min. The mechanism of this system was proposed to occur via the interaction of brominating agent with Pd(0) by oxidative addition, followed by reductive elimination. For the second system, high yield of bromosilane could be achieved by using hexabromoacetone (Br₃ CCOCBr₃ ) in the presence of UV irradiation (254 nm, 6W) within 45 min. The mechanism was believed to occur via a radical pathway supporting by the evidence of trapping experiment. In addition, the relative reactivity of brominating agent towards the synthesis of bromosilane was studied. Br₃ CCOOEt revealed the highest reactivity. These developed methodologies could further be applied for the synthesis of silyl ethers and silyl esters in high yield by one-pot reaction.