“On Water” Direct Organocatalytic Cyanoarylmethylation of Isatins for the Diastereoselective Synthesis of 3‑Hydroxy-3-cyanomethyl Oxindoles

An “on water”
organocatalytic cyanoarylmethylation
of aryl acetonitrile to isatins is developed, giving products in high
yields and up to excellent diastereoselectivities. A remarkable enhancement
of reaction rates and diastereoselectivities by water was observed
under mild conditions. Moreover, this approach provides a highly efficient
and environmentally benign access to thermodynamic 3-hydroxy-3-cyanomethyl
oxindoles.

本研究开发了一种以界面水相（on water）为介质的有机催化反应体系，实现芳基乙腈与靛红的氰基芳基甲基化反应，所得产物收率优异，非对映选择性可达极佳水平。在温和反应条件下，水可显著提升该反应的速率与非对映选择性。此外，该方法为制备热力学稳定的3-羟基-3-氰甲基羟吲哚（oxindoles）提供了一条高效且环境友好的路径。