Ionic liquid as a recyclable and efficient medium for lipase-catalyzed asymmetric cross aldol reaction

PPL (lipase from porcine pancreas) was found to catalyze asymmetric cross aldol reactions of aromatic and heteroaromatic aldehydes with various ketones in ionic liquid ([BMIM][PF 6 ]) for the first time. Interestingly, PPL exhibited high catalytic activity and excellent stereoselectivity in this efficient and recyclable room temperature ionic liquid in the presence of moderate water, similar to the results obtained in organic solvents. High yields of up to 99%, excellent enantioselectivities of up to 90% ee, and good diastereoselectivities of up to >99:1 dr were achieved.