Practical Intermolecular Hydroarylation of Diverse Alkenes via Reductive Heck Coupling

The hydroarylation of alkenes is
an attractive approach to construct
carbon–carbon (C–C) bonds from abundant and structurally
diverse starting materials. Herein we report a palladium-catalyzed
reductive Heck hydroarylation of aliphatic and heteroatom-substituted
terminal alkenes and select internal alkenes with an array of (hetero)­aryl
iodides. The reaction is anti-Markovnikov selective with terminal alkenes
and tolerates a wide variety of functional groups on both the alkene
and (hetero)­aryl coupling partners. Additionally, applications of
this method to complex molecule diversifications are demonstrated.
Mechanistic experiments are consistent with a mechanism in which the
key alkylpalladium­(II) intermediate is intercepted with formate and
undergoes a decarboxylation/C–H reductive elimination cascade
to afford the saturated product and turn over the cycle.