New synthesis of t-butyl arylpropiolates using diazo(trimethylsilyl)methylmagnesium bromide

Diazo(trimethylsilyl)methylmagnesium bromide smoothly reacted with t-butyl aryl(oxo)acetates to afford the corresponding arylpropiolates via alkylidenecarbene intermediates. In this reaction system, the magnesium bromide salt of trimethylsilyldiazomethane was significantly efficient compared to the lithium one, commonly known as a reagent for the conversion of aldehydes and aryl ketones into acetylenes.