Temperature‐Controlled Dearomative [5+1] Spiroannulation and Formal [5+2] Cyclization of Indoles with Enynones: Divergent Synthesis of Spiro‐Indolenines and Dihydrocyclohepta[b]Indolones

Abstract We developed a temperature‐controlled intermolecular dearomative [5+1] spiroannulation and [5+2] cyclization of indoles with enynones, smoothly delivering a variety of spiroindolenines and dihydrocyclohepta[ b ]indolones under 40 °C and 80 °C, respectively. A three‐step cascade reaction was also realized by using OTBS or NHBoc containing enynones in the reaction with the indole under the identical condition. And a novel valuable highly‐oriented three‐dimensional indole‐based tetracyclic scaffold was produced in high yields with excellent diastereoselectivities. Additionally, various spiroindolines and spirooxindoles were facilely produced through simple operations. This highly efficient domino‐reaction represents an emblematic method for the preparation of indole‐based polycycles through the intermolecular pathway.