Highly Regio- and Enantioselective Formal [3 + 2]-Annulation of Indoles with Electrophilic Enol Carbene Intermediates

• DOI: 10.1021/acs.orglett.6b02192
• Publication Date: 2016-09-02T18:31:22Z
• Authors: Changcheng Jing; Qing-Qing Cheng; Yongming Deng; Hadi Arman; Michael P. Doyle
• Keywords: Annulation; Cyclopentanes

Chiral cyclopentane-fused indolines are synthesized with high regio- and enantiocontrol by formal [3 + 2]-annulation reactions of indoles electrophilic enol carbenes. High enantioselectivity exclusive regiocontrol occurred enoldiazoacetamides using a less sterically encumbered prolinate-ligated dirhodium(II) catalyst in N-substituted without substituents at the 2- or 3-positions via selective vinylogous addition process. In this transformation, donor–acceptor cyclopropenes generated from serve as carbene precursors to form metal intermediates.