Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K.
Org Lett. 2019 Sep 6;21(17):6658-6662. doi: 10.1021/acs.orglett.9b02194. Epub 2019 Aug 9.
A mild, reductive spirocyclization of indole-linked amides and lactams for the efficient and selective synthesis of aza-spirocyclic indoline products is described. The catalytic reductive activation of tertiary amides or lactams by Vaska's complex with tetramethyldisiloxane as the terminal reductant allowed iminium ion formation, before a diastereoselective 5-endo-trig spirocyclization of the tethered indole moiety was triggered. Terminal reduction affords the aza-spiroindoline products in an overall highly chemoselective and diastereoselective one-pot process.
描述了一种温和的、还原的吲哚连接酰胺和内酰胺的螺环化反应，用于高效和选择性合成氮杂螺环吲哚啉产物。Vaska 配合物与四甲基二硅氧烷作为末端还原剂催化三级酰胺或内酰胺的还原活化，形成亚胺离子，然后连接的吲哚部分发生非对映选择性的 5-endo-trig 螺环化反应。末端还原以总体上高度化学选择性和非对映选择性的一锅法得到氮杂螺环吲哚啉产物。
