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O
Pd (OAc)
2
(2 mol%)
CO (1 bar), dioxane
100 °C, 5 h
N
2
+
BF
4
-
B(OH)
2
30 examples
49- 90%
R
R'
iPr
iPr
R
R'
N
+
Cl
-
iP r iPr
Scheme 10.56 Pd-catalysed carbonylative coupling of aryldiazonium salts.
O
B(OH)
2
X
Pd(OA c)
2
(2 mol% )
CO (1 bar), TH F
50 °C, 10 h
R
R'
NN
X=I,N
2
BF
4
R
R'
S
2 mol%
33 e xamples
30-98%
Scheme 10.57 A thiourea-based ligand in carbonylative Suzuki reactions.
O
BF
3
.OEt
2
(1.0 e quiv)
Pd
2
(dba)
3
(2mol%)
P(tBu)
3
(8 mol%)
CO (1 bar), D M E
RT , 1 h
N
N
N
MeO
B(OH)
2
OMe
70%
Scheme 10.58 Pd-catalysed carbonylative coupling of a 1-aryltriazene.
not reduce the product yields and also ortho-substituted arylboronic acids
resulted in good yields. In 2004, Yang and co-workers described a thiourea-
based ligand for the palladium-catalysed carbonylative coupling of aryl
iodides or aryldiazonium salts with arylboronic acids.
70
This sterically bulky
thiourea ligand was successfully applied under aerobic conditions and ke-
tones were synthesized in good to excellent yields (Scheme 10.57).
Tamao and co-workers reported an example of the carbonylative coupling
of a 1-aryltriazene with a boronic acid in 2004.
71
The corresponding diaryl
ketone was produced in 70% yield under 1 bar of CO, in the presence of a
catalytic amount of Pd
2
(dba)
3
and P(tBu)
3
(Scheme 10.58).
Långstr¨m and co-workers reported the synthesis of
11
C- and
13
C-labelled
ketones by palladium-catalysed carbonylative Suzuki coupling.
72
Aryl tri-
flates with methyl- or arylboronic acids and a low concentration of
11
CO were
employed in the synthesis of
11
C-labelled ketones using Pd(PPh
3
)
4
as cata-
lyst. The
11
C-labelled products were obtained with decay-corrected radio-
chemical yields in the range 10-70% after a reaction time of 5 min at 150 1C.
The first report of the synthesis of b-keto sulfoxides using a palladium-
catalysed carbonylative Suzuki reaction of an a-bromosulfoxide with aryl-
boronic acids appeared in 2005.
73
Asensio and co-workers reported the
synthesis of 12 b-keto sulfoxides in moderate to excellent yields using
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