Metal-free alkene hydroboration with pinacolborane employing C6F5BH2·SMe2 as a precatalyst

Abstract

We have developed C₆F₅BH₂·SMe₂ as a unique, metal-free precatalyst for alkene hydroboration. It combines high reactivity and excellent regio- and chemoselectivity. Mechanistic studies reveal that the catalyst's structure is nearly ideal: the transborylation step occurs via an [sp³-C–B/B–H] transition state and the hydroborylation step goes through a low barrier (ΔG^‡ = 15.2 kcal mol⁻¹) with cyclohexene as a substrate.