Diastereoselective synthesis of spirooxindole derivatives via biocatalytic domino reaction

A facile promiscuous reaction catalyzed by Acylase ‘Amano’ was developed for the preparation of spirooxindole derivatives. At the optimized reaction condition, the acylase-catalyzed domino reactions could provide a series of different spirooxindole products in moderate yields and good diastereoselectivity. A chemo-enzymatic two-step process was also designed successfully, and several representative spirooxindole derivatives could be obtained in nearly quantitative yields. Additionally, one tentative mechanism for this enzyme-catalyzed process was proposed.