Acylative Dynamic Kinetic Resolution of Secondary Alcohols: Tandem Catalysis by HyperBTM and Backvall's Ruthenium Complex

Non-enzymatic dynamic kinetic resolution (DKR) of secondary alcohols by enantioselective acylation using an isothiourea-derived HyperBTM catalyst and racemization of slowly reacting alcohol by Backvall's ruthenium complex is reported. The DKR approach features high enantioselectivities (up to 99:1), employs easy-to-handle crystalline 4-nitrophenyl isobutyrate as the acylating reagent, and proceeds at room temperature and under an ambient atmosphere. The stereoinduction model featuring cation-pi system interactions between the acylated HyperBTM catalyst and pi electrons of an alcohol aryl subunit has been elaborated by DFT calculations.

Automated summary

The study presents a non-enzymatic dynamic kinetic resolution (DKR) of secondary alcohols using an isothiourea-derived HyperBTM catalyst and Backvall's ruthenium complex, achieving high enantioselectivities at room temperature. A stereoinduction model based on cation-pi system interactions has been elaborated through DFT calculations.