The Plancher rearrangement (sometimes referred to as the Plancher-Ciamician rearrangement) is defined as the acid-catalyzed conversion of 3,3-disubstituted indolenines to 2,3-disubstituted indoles. Mechanistically, the reaction involves a Wagner–Meerwein type 1,2-rearrangement of spiroindoleninium cations followed by rearomatization of the newly generated, more stable cationic species into 2,3-disubstituted indoles with the loss of a proton. To stop this rearrangement process, synthesis and reactions of 3,3-disubstituted indolenines are typically carried out under basic conditions. During our synthetic efforts on indole chemistry, recently we have serendipitously discovered three new findings: (a) ipso-selective, dearomative epoxide–indole cyclization, (b) interrupted Plancher rearrangement, and (c) aza-Friedel–Crafts reaction under basic conditions. In each of these three cases, the expected rearomatization process after the indole dearomatization step could successfully be halted, thereby allowing us to access spiroindolenines and polycyclic indolines as bench-stable products under full diastereocontrol and in high yields. The detailed synthetic studies towards these molecules will be presented in the seminar.1-4