complex: The asymmetric one‐step construction of multiplestereocenters in complex spirocyclicoxindoles was achieved with very high fidelity by using distinct organocascade reactions utilizing two organocatalysts, each activating different carbonyl compounds (see scheme; TMS=trimethylsilyl). The complementary approaches demonstrate the potential of organocascadecatalysis to face challenging synthetic
A novel approach for the synthesis of unprecedented C3-mono-functionalized indolin-2-ones is reported, starting from 2-oxindole and chalcones. The reactions proceed regioselectively under mild conditions, without di- and tri-alkylated side products. The new compounds have been evaluated in vitro for their antiproliferative effects against the protozoan Leishmania infantum. Interestingly, they appear able to kill L. infantum promastigotes and amastigotes, without significant cytotoxic effects. (C) 2014 Elsevier Ltd. All rights reserved.