The dealkylation of phosphate and phosphonate esters by lodotrimethylsilane : a mild and selective procedure

Abstract

Iodotrimethylsilane transforms alkyl esters of phosphorus oxyacids into their corresponding trimethylsilyl esters and alkyl iodide. The reaction is rapid and quantitative at room temperature. The reagent has no effect on aryl phosphate ester functions or upon alkyl carboxylate, ether, bromoalkane, vinyl, and ethynyl functions under the conditions employed for transesterification. The trimethylsilyl esters can be isolated by distillation or solvolysed without purification using methanol or water to afford dealkylated phosphate and phosphonate species. Selective monodealkylation of dialkyl phosphonates cannot be achieved using only one equivalent of the reagent, which leads to the formation of mixed products.