The efficient method for the preparation of alkenylsilanes from organoaluminums

Abstract

Silyl esters of sulfonic acids are convenient and efficient silylating agents for β,β- and β-substituted 1-alkenylaluminums. The reaction proceeds at room temperature in CH2Cl2 or hexane for 18 h to give corresponding alkenylsilanes in high yield. At the same time, α,β-disubstituted and α,β,β-trisubstituted 1-alkenylaluminums were inert in the reaction under study. The reaction with aluminacyclopen-2-enes and aluminacyclopentanes takes place on the less sterically hindered reaction center. Using electron-donating solvents (diethyl ether, THF) inhibits the reaction. A new convenient procedure of silylation was developed, which consists in obtaining the silyl tosylate by the reaction of chlorosilanes with anhydrous sodium tosylate in toluene solution. The resulting reaction mixture was reacted with organoaluminum compounds without isolation of silyl tosylate.