om7b00563_si_001.pdf (1021.4 kB)
C–H Activation of π‑Arene Ruthenium Complexes
journal contribution
posted on 2017-11-08, 16:14 authored by Luke A. Wilkinson, Jack A. Pike, James W. WaltonWe present a C–H activation
protocol for aromatic compounds
that overcomes the current limitations of the need for a directing
group or covalently bound activating groups, by exploiting the increase
in C–H acidity of aromatic compounds on π-coordination to a Ru(II) center. The increased
acidity facilitates catalytic concerted metalation–deprotonation
and subsequent arylation reactions. We present the development and
optimization of the C–H activation protocol and show the applicability
of the reaction to a range of aromatic substrates, including the simplest
of substrates (benzene). Furthermore, we demonstrate the recyclability
of the activating Ru(II) fragment using photolysis and give a mechanistic
study, which provides strong evidence that this reaction occurs via
a silver-mediated C–H bond activation. This is the first time
Ru complexes have been shown to allow C–H activation of arenes
by a π-coordination mechanism.