301
TEMPO (5 mol%)
KOH (0.5 equiv)
CH 3 CN/H 2 O (1:1), 80
o C
Pb
C
N
R
OH
Ar 2
Ar 1
N
R
Ar 2
Ar 1
Scheme 90 Electrochemical dehydrogenative cyclization of oximes
KOAc, n-Bu 4 NClO 4
RuCl 2( p-cymene) 2
(5 mol%)
t-AmOH/H 2 O
100
o C, 24 h
CCE at 1.5 mA
Pt
RVC
R 3
R 2
HN
CO 2 R
OH
NCO 2 R
R 2
R 3
O
R 2
R 3
Scheme 91 Electrochemical C–H activation of phenols/carbamates with alkynes
Co(OAc)2 4H 2 O (10 mol%)
NaOPiv, MeOH
40
o C, 15 h
undivided cell
CCE at 2mA
RVC
Pt
N
H
O
DG
Ar
R 1
•
R 2
R 3
N
O
DG
Ar
R 1
R 3
R 2
Scheme 92 Electrochemical allene annulation
RuCl 2( p-cymene) 2 (5 mol%)
NaOPiv (1 equiv)
n-Bu 4 NClO 4 (1 equiv)
i-PrOH/H 2 O (3/ 1 )
100
o C, Ar, 10 mA
NH 2
O
Ar
N
O
Ar
R 1
R 1
R 1
Scheme 93 Electrochemically enabled dual C−H activation of amides
sturdiness and flexibility of the designed electrochemical C–H annulation strategy
were reproduced for different allene moieties in significant yields. Similarly, C−H/
N−H functionalization with allenes was demonstrated by the same group using
Insights into Sustainable C–H Bond Activation