Diastereodivergent Synthesis of 3‐Spirocyclopropyl‐2‐oxindoles through Direct Enantioselective Cyclopropanation of Oxindoles

Falling like dominos : The first direct organocatalytic asymmetric cyclopropanation reaction of oxindole was developed, in which oxindoles were employed as a dinucleophilic C 1 synthon and bromonitroolefins with a dielectrophilic center were used as a C 2 synthon (see scheme). An amino acid based multifunctional catalyst promoted the [2+1] reaction, giving the products in high yields and excellent enantioselectivities. A divergent synthesis of different stereoisomers of 3‐spirocyclopropyl‐2‐oxindoles was achieved.