A radical cascade reaction of aza-1,6-enyne compounds using allyltributyltin

Abstract

The radical cascade reaction of allyltin with aza-1,6-enyne compounds was studied. Optically active aza-1,6-enynes underwent a radical cascade process in the presence of a high concentration of allyltributyltin to give stannolanes as the major isomer. Piperidines were also observed in small amounts when an allylic unit was introduced stereoselectively to the trans-position of the aryl group at the C2 position. The yield of the products dramatically decreased with concentrations of tin reagent. The E/Z selectivity at the exomethylene group in piperidine depended on the reaction temperature, and it almost doubled when the reaction was carried out at 30 °C. In this study, the reaction mechanism of the radical cascade is discussed.