C–H Bond Alkylation of Cyclic Amides with Maleimides via a Site-Selective-Determining Six-Membered Ruthenacycle

The first example of a ruthenium-catalyzed C–H
bond alkylation
via six-membered ruthenacycles is presented. This is disclosed for
the C–H bond alkylation of biologically relevant cyclic amides
with maleimide derivatives. The cyclic tertiary amide core acted as
a directing group (DG) enabling formation of six-membered cycloruthenated
species responsible for the control of the regio- and site selectivity
of the reaction as well as the excellent functional group tolerance.
Unexpectedly, cyclic amides were found to be better DGs than pyridine-containing
ones or cyclic imides for this type of C–H bond functionalization.