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[Pd(SIPr)(allyl)Cl] (7 9)
(1 mo l%)
O
O
X
R''
+R''
R
NaO
t
Bu
TH F , 50 - 70° C
0.2 - 6h
R
R'
R'
X = Cl, Br, OTf
NN
CF
3
OMe
O
O
O
N
Pd
Cl
X=Cl:78%
X=OTf:87%
X=Cl:81%
X=Cl:60%
[Pd(SIPr)(allyl)Cl]
7 9
O
O
X=Br:72%
X=Br:68%
Scheme 4.56 a-Arylation of ketones catalysed by [Pd(SIPr)(allyl)Cl].
[Pd(IPr)(OAc)
2
](80)
(1 mol%)
O
O
Cl
R''
+R''
NN
R
NaOt Bu
1,4-dioxane, RT
12 - 1 8h
R
R'
R'
Pd
OAc
O
O
OMe
O
O
O
[Pd(IPr)(OAc)
2
]
80
OMe
75%
71%
67%
Scheme 4.57 Room temperature a-arylation using [Pd(IPr)(OAc)
2
].
found that the use of microwave irradiation (130 1C) could significantly
decrease the reaction time to 2 min.
Nolan and co-workers also utilized [Pd(IPr)(acac)Cl] (82), which showed
high activity in the reaction (Figure 4.36).
160
The advantage of this pre-
catalyst is its ease of preparation. Other groups also studied the effect of
alternative throwaway ligands in this reaction. For example, Zhang et al.
prepared the IPr-based cyclopalladated ferrocenylimine complex 83
(Figure 4.36).
161
The complex exhibited high activity for the a-arylation of
various ketones using aryl chlorides and bromides, including deactivated
and sterically hindered congeners. Xiao and Shao also utilized the [Pd(I-
Pr)(Im)Cl
2
] complex in the coupling (16a, Figure 4.36).
162
Another interesting contribution was made by Navarro and co-workers,
163
who reported a domino palladium-catalysed oxidation/arylation of second-
ary alcohols. [Pd(IPr)(allyl)Cl] (84) was identified as the best precatalyst to
promote the reaction. Desired coupling products were isolated in good yields
(Scheme 4.58).
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