Asymmetric Synthesis of cis-Indolinones

Significance

The authors report an efficient asymmetric carbocyclization giving rise to the ­indolinone scaffold via [3+2] cyclization of an ­indole scaffold with alkynyl Fischer carbene complexes. The authors were responsible for the development of methodology to access enantiopure alkynyl Fischer carbenes and have previously demonstrated their ability to induce selectivity in cyclization reactions. The present work further demonstrates their utility in such reactions.