3‑Chloro-1-lithiopropene, a Functional Organolithium Reagent, and Its Reactions with Alkylboronates To Give 3‑Alkylprop-1-en-3-ols

The reagent 3-chloro-1-lithio­propene (<b>4</b>) can be generated by treating 1-bromo-3-chloro­propene with <i>t</i>-BuLi. It is unstable but if generated at low temperature in the presence of alkylboronic esters, such as <b>3</b>, is trapped in situ to give rearrangement products <b>2</b>, which on oxidation give 3-alkylprop-1-en-3-ols in good yields. The reaction works for primary, secondary, benzylic, and even tertiary alkylboronic esters, providing allylic alcohols bearing almost any alkyl group available using organoborane chemistry and incorporating all features of such groups.