Dedicated to Professor Victor Snieckus on the occasion of his 80th birthday
Abstract
The asymmetric synthesis of trifluoromethylated 3,3′-pyrrolidinyl-dispirooxindole derivatives with four contiguous stereogenic centers, including two vicinal spiro-stereocenters, is described. Employing a bifunctional thiourea catalyst, a domino Michael–Mannich [3+2] cycloaddition occurs readily between isatin ketimines and isatin-derived enoates with good yields and very high stereoselectivities, providing a direct entry to the title compounds of potential medical value.
Key words
asymmetric synthesis - dispirooxindole - organocatalysis - domino reaction - Michael–Mannich [3+2] cycloaddition