Crystal Structure of the Monocarborane Magnesium(II) Acetylide and Its Use in the Synthesis of α,β-Unsaturated Ketones

We report the first crystal structure of heteroleptic Grignard reagent 2based on the carborane endo/exodianion [CB11H11-12-C≡C]2–. Full characterization reveals a rare coordination pattern and affirms the bimetallic nature. Navigating the reactivity landscape, we unlock the potential of 2in nucleophilic addition with ketones to afford propargylic alcohols 3, renowned for their synthetic versatility and potential biological activities, and unveil the Meyer–Schuster rearrangement, yielding α,β-unsaturated carbonyl compounds 4. This narrative of synthesis, characterization, and reactivity opens new horizons for carborane chemistry, offering avenues for innovation and facile functionalization of carborane scaffolds.