Ambient Moisture Accelerates Hydroamination Reactions of Vinylarenes with Alkali-Metal Amides under Air

Angew Chem Int Ed Engl. 2020 Oct 19;59(43):19021-19026. doi: 10.1002/anie.202008512. Epub 2020 Aug 28.

Abstract

A straightforward alkali-metal-mediated hydroamination of styrenes using biorenewable 2-methyltetrahydrofuran as a solvent is reported. Refuting the conventional wisdom of the incompatibility of organolithium reagents with air and moisture, shown here is that the presence of moisture is key in favoring formation of the target phenethylamines over competing olefin polymerization products. The method is also compatible with sodium amides, with the latter showing excellent promise as highly efficient catalysts under inert atmosphere conditions.

Keywords: alkali metals; hydroamination; lithium; solvent effects; synthetic methods.