Efficient synthesis of 5-(hydroxymethyl)piperazin-2-ones using automatically prepared chiral bromocarboxylic acid and Garner's aldehyde as versatile building blocks.

An efficient method for the synthesis of substituted 5-(hydroxymethyl)piperazin-2-ones was established by using an automated synthesis process. Thirteen piperazinones were synthesized from chiral α-bromocarboxylic acids and Garner's aldehyde which were prepared by using our originally developed automated synthesizer, ChemKonzert®. The automated method of synthesizing chiral α-bromocarboxylic acids was efficient and safe because the rate of the dropwise addition of the reagent can be controlled using the automated synthesizer. This method is expected to contribute to the synthesis of pharmaceuticals.

Acylalkylation of Arynes Generated from o-Iodoaryl Triflates with Hydrosilanes and Cesium Fluoride.

An efficient method to generate aryne intermediates from o-iodoaryl triflates triggered by triethylsilane and cesium fluoride is disclosed. This method realized the acylalkylation of arynes using easily available o-iodoaryl triflate-type precursors, which was difficult when using conventional nucleophilic activators. A wide range of (hetero)arenes including various fused benzothiazoles were successfully synthesized from o-iodoaryl triflates by virtue of their good accessibility and divergent transformations of aryne intermediates.