Preparation of Highly Reactive Lithium Metal Dendrites for the Synthesis of Organolithium Reagents

A long-standing problem in the area of organolithium chemistry has been the need for a highly reactive Li-metal source that mimics Li-powders but has the advantage of being freshly prepared from inexpensive and readily available Li-sources. Here, we report a simple and convenient activation method using liquid ammonia that furnishes a new Li-metal source in the form of crystalline Li-dendrites. The Li-dendrites were shown to have ca. 100 times greater surface area than conventional Li-sources created by prototypical mechanical activation methods. Concomitant with the surface area increase, the Li-dendrites were shown to exhibit significant rate enhancements over Li-powders, which are currently the industry standard for the preparation of organolithium compounds. These features were leveraged for the reproducible synthesis of organolithium reagents over a range of common laboratory scales.