A new methodology has been developed for the highly efficient diastereoselective construction of dihydrocoumarin–pyrrolidine–spirooxindole collections via a domino Michael/annulation reaction of 3-isothiocyanato oxindoles and coumarins under catalyst-free conditions. The resulting biologically important molecules bearing three pharmacophores and three contiguous stereocenters were obtained in up to 92% yield and >20:1 dr. It is noteworthy that utilization of a carboxylic acid activation/decarboxylation strategy represents an efficient approach for the domino Michael/annulation reaction of the chemically inert coumarin moiety. This protocol could expand candidate libraries, that will benefit the requirement for new bioactive molecules.
Key words
dihydrocoumarins - pyrrolidines - spirooxindoles - 3-isothiocyanato oxindoles - catalyst-free
