Iron-
and manganese-catalyzed
para
-selective oxidative
amination of (4-R)phenols by primary and secondary anilines was developed.
Depending on the identity of the R group, the products of this efficient
reaction are either benzoquinone anils (C–N coupling) that
are produced via a sequential oxidative amination/dehydrogenation
(R = H), oxidative amination/elimination (R = OMe) steps, or
N
,
O
-biaryl compounds (C–C coupling)
that are formed when R = alkyl through an oxidative amination/[3,3]-sigmatropic
rearrangement (quinamine rearrangement) process.