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O
Br
Pd(PPh
3
)
4
(5 mol%)
K
2
CO
3
, dioxane
85-100 °C, CO (12 bar)
B(OH)
2
18 examples
21-73 %
Br
N
H
NH
2
R
R
R'
R'
Scheme 10.69 Pd-catalysed synthesis of 2-aroylindoles.
O
Pd (1 mol%)
CO (5 bar)
Na
2
CO
3
,90 °C
dioxane
Ph
2
P
X
B(O H)
2
R'
I
Pd
R
R'
R
14 examples
43-98%
Ph
2
P
Scheme 10.70 Pd-catalysed carbonylative Suzuki coupling of aryl halides with
arylboronic acids.
B(O H)
2
Cl
Pd(OAc)
2
/PCy
3
K
3
PO
4
,H
2
O
80 °C, 20 h
12 examples
41-78%
R''
O
R'
R''
R'
Scheme 10.71 Pd-catalysed carbonylative coupling of benzyl chlorides.
produced in good yields (Scheme 10.69). Since this reaction tolerates various
functional groups, a practical route to a wide range of 2-aroylindoles is
possible starting from 2-gem-dibromovinylanilines.
In 2010, Gelman and co-workers reported a new bidentate phosphine
ligand for palladium-catalysed carbonylative Suzuki coupling reactions.
86
Aryl iodides and bromides were coupled with arylboronic acids in the
presence of 0.01-1 mol% of catalyst. Ketones were produced with high se-
lectivity in good yields (Scheme 10.70).
Recently, Beller's group reported a novel carbonylative coupling of benzyl
chlorides with arylboronic acids.
87a
This was the first report on carbonylative
Suzuki couplings of benzyl chlorides with arylboronic acids (Scheme 10.71).
The reaction is carried out using a commerically available Pd(OAc)
2
/PCy
3
catalyst in the presence of K
2
CO
3
and water as solvent. Twelve ketones were
synthesized in good yields. Later, this was extended to reactions with
ArBF
3
K.
87b
10.5 Carbonylative C-H Activation Reactions
As noted in the Introduction, it would be advantageous to use C-H deriva-
tives rather than the C-halogen substrates described thus far. The activation
of 1-alkynes by Pd/Cu catalysts is an established protocol following the work
of Sonogashira, as noted above. If the acyl palladium intermediate is trapped
by a nucleophile other than an aryl group derived from an aryl halide, then a
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