Asymmetric Synthesis of spiro[benzofuran-pyrrolidine]-indolinedione via Bifunctional Urea Catalyzed [3+2]-annulation Reaction

Herein, we demonstrate the first employment of ( E )-alkylidine benzofuran-2-one for the high enantio- and diastereoselective construction of trifluormethylated spiro[benzofuran-pyrrolidine]indolinedione.