One-Pot Sustainable Synthesis of Tertiary Alcohols by Combining Ruthenium-Catalysed Isomerisation of Allylic Alcohols and Chemoselective Addition of Polar Organometallic Reagents in Deep Eutectic Solvents

The Ru(IV)-catalysed redox isomerisation of allylic alcohols has, for the first time, been successfully assembled with the chemoselective addition of organolithium or organomagnesium reagents to the in situ formed ketones, en route to tertiary alcohols, employing Deep Eutectic Solvents as environmentally friendly reaction media. The overall transformation, which formally involves three consecutive and different steps such as (i) the reduction of a C–C double bond, (ii) the oxidation of a secondary carbinol moiety, and (iii) a chemoselective C–C bond formation, takes place in protic and biorenewable eutectic mixtures in a sequential one-pot fashion using a commercially and easily available catalytic system, with excellent conversions (up to 99% yield), at room temperature and under air in the last step, with no concomitant reduction or enolisation processes, and with high atom economy, in agreement with the principles of the socalled Green Chemistry.