title: Iron-catalyzed directed C2-alkylation and alkenylation of indole with vinylarenes and alkynes.
abstract: An iron-N-heterocyclic carbene catalyst generated from an iron(III) salt, an imidazolinium salt, and a Grignard reagent promotes alkylation and alkenylation reactions at the indole C2-position with vinylarenes and internal alkynes, respectively, via imine-directed C-H activation. The former reaction affords 1,1-diarylalkane derivatives with exclusive regioselectivity. Deuterium-labeling experiments suggest that these reactions involve oxidative addition of the C-H bond to the iron center, insertion of the unsaturated bond into the Fe-H bond, and C-C reductive elimination.
authors.affiliation: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University , Singapore 637371, Singapore.
authors.forename: Mun Yee
authors.initials: MY
authors.lastname: Wong
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamakawa
authors.forename: Naohiko
authors.initials: N
authors.lastname: Yoshikai