Synthesis of\nγ‑Spirolactams via Rh(III)-Catalyzed\nC–H Activation/Directing Group Migration/Dearomatization/Spiroannulation\nof Indoles with 1,3-Enynes

1,3-Enynes are valuable coupling partners in transition-metal-catalyzed\nC–H functionalizations. Certainly, aliphatic-substituted 1,3-enynes\nhave been thoroughly investigated in C–H functionalizations,\nwhereas aromatic-substituted 1,3-enynes remain underexplored. Herein,\nwe report the realization of this goal, where we achieve an atom-economical\nprotocol for the synthesis of γ-spirolactams via Rh(III)-catalyzed\nC–H functionalization of <i>N</i>-carbamoylindoles\nwith 1,3-enynes. The reaction proceeds through a unique cascade strategy,\nsuch as C–H activation/directing group (DG) migration/indole\ndearomatization/spiroannulation, to access novel and synthetically\nchallenging spiro[indoline-2,2′-pyrrolidin]-5′-one scaffolds.\nMoreover, the isolation of intermediate and mechanistic and ESI-HRMS\nstudies further provide valuable insights into the proposed catalytic\ncycle.