4 FLP-Mediated C–H-Activation
157
E
E
[B]
27 A (25 mol%)
furBCat (5 equiv.)
N
Me
N
Me
Me
BCat
BCat
N
Me
BCat
Me
N
Me
BCat
MeO
N
Me
BCat
NC
N
BCat
NC
N
BCat
N
BCat
N
BCat
Et
N
Me
BCat
N
BCat
CN
S
BCat
MeO
N
Me
BCat
MeOOC
BCat
Me 2 N
>95%
92%
83%
93%
60%
89%
83%
77%
74%
>95%
64%
86%
23%
9%
C 6 D 6 , 24 h, 110 °C
sealed vessel
Scheme 4.50 Substrate scope for the C–H transfer borylation using 2-mercaptopyridine
N
SH
N
Me
O
BCat
O
N
SH
CatB
O
N
Me
Resting State
(0)0
N
SH
CatB
N
Me
CatB
N
S
BCat
N
S
B
Int54
Int54*
H
H
Int53
8.2 (-3.7)
Int55
11.0 (-1.9)
27 A
1.1 (2.3)
N
S
CatB
H
TS21
B-C Cleavage
O
N
S
CatB
H
N
Me
Cat
TS20
TS21
21.3 (6.5)
TS20
27.3 (13.3)
C-H Activation
Fig. 4.15 Mechanism of C–H transfer borylation using 2-mercaptopyridine