Synthesis of spirocyclopentene-indolines by intramolecular alkylidine insertion reactions

Intramolecular 1,5 CH insertion of unstabilized carbenes into the tertiary carbon of a substituted indoline generates spiro[cyclopent[2]ene-1,2'-indolines] in good yields and excellent enantioselectivities. (C) 2008 Elsevier Ltd. All rights reserved.