Chemistry Reference
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Table 4.6 Reactivity of [Pd(NHC)(cin)Cl] (27) in the Suzuki
reaction.
[P d(NHC)(cin)Cl]
(
27
)
(0.5 mol%)
NaHCO
3,
TBAB
H
2
O, reflux
B(OH)
2
Cl
+
N
N
n
27a
:n=0,Ar=Mes
27b
:n=0,Ar=Dipp
27c
:n=1,Ar=Mes
27d
:n=1,Ar=Dipp
27e
:n=2,Ar=Mes
27f
:n=2,Ar=Dipp
N
N
Ar
Ar
Pd
Cl
Ph
[Pd(NHC)(cin)Cl]
Entry
[Pd(NHC)(cin)Cl] (27)
Yield (%)
1
27a
3
2
27b
33
3
27c
15
4
27d
84
5
27e
86
6
27f
25
[Pd(IPr)(Im)Cl
2
]
(
16a
)
(1.5mol%)
KOH
H
2
O, 60°C
R'
Cl
R
+
X
R
R'
X=B(OH)
2
orBF
3
K
F
90%
99%
97%
S
O
F
70%
76%
Scheme 4.11 Preparation of diarylmethane derivatives using 16a.
in water (Table 4.6).
63
Complexes 27d and 27e (six- and seven-membered ring,
respectively) were found to be the most active congeners for the coupling of
3-chloropyridine and 4-tolylboronic acid. Interestingly, the reaction is suc-
cessful under air, using TBAB as a transfer agent and NaHCO
3
as an en-
vironmentally benign base.
In a rare example of coupling involving benzylic chlorides, Lu and co-
workers determined the activity of [Pd(IPr)(Im)Cl
2
](16a) in neat water.
64
The
methodology allowed the preparation of an interesting library of dia-
rylmethane derivatives that are important compounds for the pharma-
ceutical industry (Scheme 4.11).
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