Table 2 Scope for synthesis of ortho-CF3 acetanilides from 2a
Notes and references
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reaction of a 1 : 1 mixture of acetanilide and deuterium-
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(Scheme 5). This observation indicates that C–H bond activa-
tion is the rate-determining step in the catalytic cycle. Further-
more, we used the pre-generated palladacycle19 of acetanilide
(see ESIw) as the starting material to react with 2 equiv.
(Bpin)2. In this reaction, 2a was obtained in 75% yield. On
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reductive elimination. Finally, Pd(0) was re-oxidized to Pd(II)
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In summary, we developed an alternative method for
Pd(II)-catalyzed directed C–H activation/C–B cross-coupling
of acetanilides under acidic conditions. The new reaction can
be conducted under relatively mild conditions without any
inert air protection. It shows a good functional group tolerance
and an exclusive mono-selectivity. Through the studies on the
conversion of C–H bonds into C–aryl/heteroaryl and C–CF3
bonds, we demonstrate that the C–H borylation method may
provide a generally applicable route for the conversion of C–H
moieties into many other types of bonds.
This study was supported by the National Natural Science
Foundation of China (Grant No. 20932006, 20972148) and the
NCET (080519).
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c
4856 Chem. Commun., 2012, 48, 4854–4856
This journal is The Royal Society of Chemistry 2012