Oxometallate-Based Ionic Liquid Catalyzed CO2-Promoted Hydration of Propargylic Alcohols for α-Hydroxy Ketones Synthesis.

α-Hydroxy ketones are a crucial class of organic compounds prevalent in natural products and pharmaceutical molecules. The CO2-promoted hydration of propargylic alcohols is an efficient method for the synthesis of α-hydroxy ketones. Herein, an ionic liquid (IL) was designed to catalyze this reaction individually under atmospheric CO2 pressure, volatile organic solvents, and additives. This IL, constructed from the molybdate anion, can be recycled from industrial (NH4)2MoO4 production wastewater, demonstrating its high tolerance to catalytic environments and significant potential for practical applications. To our knowledge, this is the first instance of an oxometallate-based IL catalyst being utilized for the CO2-promoted hydration of propargylic alcohols. Further mechanistic studies revealed the bifunctionality of this IL in activating both CO2 and substrates.