Ultrafast Addition of Highly Polar s‐Block Organometallic Reagents (RMgX/RLi) to CO2‐derived Cyclic Carbonates at Room Temperature, Under Air and in 2‐MeTHF as Sustainable Solvent

Ultrafast addition of highly-polar organometallic reagents (RMgX/RLi) into cyclic carbonates (derived from CO2 as sustainable C1 synthon) has been studied, for the first time, in 2-MeTHF as green reaction media or in the absence of external VOC solvents, at room temperature and in the presence of air/moisture (i.e., without using protecting atmosphere); reaction conditions that are generally forbidden in the field of these highly-reactive main group organometallic compounds. The correct selection of the stoichiometry and the nature of the polar organometallic alkylating/arylating reagent allows the straightforward and successful synthesis of: i) highly-substituted tertiary alcohols (through the one-pot/one-step triple addition of RLi reagents); ii) β-hydroxy-esters (via mono-addition of the corresponding alkyl-Grignard compounds); or iii) symmetric ketones (when aryl-Grignard reagents were employed); working always under air and at room temperature. Finally, we were able to design an unprecedented one-pot/two-step hybrid protocol through the synergic combination of an aluminun-catalyzed cyclization between CO2 and propylene oxide with the concomitant and ultrafast addition of RLi reagents to the in-situ and transiently formed cyclic carbonate, thus allowing the indirect conversion of CO2 into the desired highly-substituted tertiary alcohol without the need of isolation or purification steps of any reaction intermediate.