title: Mechanistic and Kinetic Studies of the Direct Alkylation of Benzylic Amines: A Formal C(sp3)-H Activation Proceeds Actually via a C(sp2)-H Activation Pathway.
abstract: Mechanistic investigations of a Rh(I)-catalyzed direct C-H alkylation of benzylic amines with alkenes, formally an C(sp3)-H activation, reveal this reaction to proceed via imine intermediates and, hence, via C(sp2)-H activation. The reaction shows a primary kinetic isotope effect of 4.3 at the benzylic C-H position together with a reversible H-D exchange at the same position, which indicates that there are at least two distinct steps in which the corresponding C-H bonds are broken. The imine intermediates are shown to be converted to the final product under the reaction conditions, and a time course analysis of the alkylated imine intermediate shows that it is formed before the final amine product in the course of the reaction.
authors.affiliation: Institute of Applied Synthetic Chemistry, Vienna University of Technology , Getreidemarkt 9/163-OC, Vienna 1060, Austria.
authors.forename: Robert
authors.initials: R
authors.lastname: Pollice
authors.affiliation: Institute of Applied Synthetic Chemistry, Vienna University of Technology , Getreidemarkt 9/163-OC, Vienna 1060, Austria.
authors.forename: Navid
authors.initials: N
authors.lastname: Dastbaravardeh
authors.affiliation: Institute of Applied Synthetic Chemistry, Vienna University of Technology , Getreidemarkt 9/163-OC, Vienna 1060, Austria.
authors.forename: Nada
authors.initials: N
authors.lastname: Marquise
authors.affiliation: Institute of Applied Synthetic Chemistry, Vienna University of Technology , Getreidemarkt 9/163-OC, Vienna 1060, Austria.
authors.forename: Marko D
authors.initials: MD
authors.lastname: Mihovilovic
authors.affiliation: Institute of Applied Synthetic Chemistry, Vienna University of Technology , Getreidemarkt 9/163-OC, Vienna 1060, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Schnürch
keywords: C−H activation; Rh(I) catalysis; cyclometalation; direct alkylation; heterogeneous reaction; kinetic isotope effects; reaction mechanism
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