1,3-Dipolar cycloaddition reaction for diastereoselective synthesis of functionalized dihydrospiro[indoline-3,2′-pyrroles]

The BF3OEt2 catalyzed one-pot 1,3-dipolar cycloaddition reaction of benzylamines, isatins and dimethyl acetylenedicarboxylate in dry methylene dichloride afforded the functionalized spiro[indoline-3,2′-pyrroles] in moderate to good yields and with high diastereoselectivity.52