86
3.4.3 Organosilicon Reagents as Nucleophiles
In 2015, Yu and co-workers reported a Pd(II)-catalyzed oxidative cross-coupling of
C(sp
3
)−H bonds with organosilicon coupling partners for the first time (Scheme 3.67)
[149]. The use of tricyclic quinoline-based ligands accelerates the C(sp
3
)−H crosscoupling efficiently so as to outcompete the homocoupling process of arylsilanes.
Notably, the reaction is tolerant of substrates containing α-hydrogen atoms. The
development of this transformation further demonstrates the potential utility of
quinoline-based ligands in Pd(II)/Pd(0)-catalyzed C−H activation reactions.
3.4.4 C(sp
3
)–H and X–M as Nucleophiles
3.4.4.1 C–H and Halo–M as Nucleophiles
In 2012, Sanford and co-workers reported the first example of Pd-catalyzed oxidative
fluorination of C(sp
3
)–H bonds of 8-methylquinoline derivatives using nucleophilic
fluoride in the presence of hypervalent iodine oxidant. The fluoride source can be
either AgF or CsF (the latter in combination with AgOTf) (Scheme 3.68) [150].
76%
6 3%
70%
72%
6 2%
57%
N
N
R
+
B
O
O
Ar
Ru 3 (CO) 12 (3.3 mol%)
tBuCOMe
N
N
R
Ar
H
N
N
Ph
N
N
Ph
N
N
Ph
CF 3
F
OMe
N
N
Ph
N
N
Ph
N
N
N
N
Me
TBSO
Scheme 3.63 Oxidative cross-coupling of Csp
3 –H bonds in pyrrolidines and piperdines with
organoboronic acid derivatives
C. He