A Convenient Iron-Catalyzed Method for the Preparation of 1,2-Bis(trimethylsilyl)benzenes

摘要

A convenient iron-catalyzed method for the preparation of l,2-bis(trimethylsilyl)benzenes is presented. Compared to the current procedures, low temperatures and toxic solvents are avoided, allowing large-scale preparation. Additionally, a variety of sub-stituents are tolerated. Trialkylsilyl-substituted aryl compounds are useful precursors for transmetalation reactions. These molecules can be prepared via radical substitution reactions, nu-cleophilic substitution reactions with trialkylsilyl alkali-metal compounds, palladium-catalyzed reactions, and [2+2+2]- or [4+2]-cycloaddition reactions. One of the most used methods is the reaction of Grignard or aryl-lithium compounds with trialkylsilyl chlorides. However, this transformation is problematic for the synthesis of l,2-bis(trialkylsilyl)aryls. In this case, elimination to the corresponding aryne is observed, which can undergo further undesired reactions (Scheme 1).