281
KPF 6 (50 mol%)
PEG-400
O 2 , 140
o
C, 20 h
Co(OAc)2 4H 2 O (50 mol%)
Ar
Ar
N
H
R 1
O
N
R 2
R 3
N
R 1
R 2
R 3
Scheme 43 Cobalt-catalysed C–H/N–N activation reaction for isoquinolines synthesis in PEG-400
RuCl 2( p-cymene) 2 (2.5 mol%)
AgSbF6 (10 mol%)
2-MeTHF, 120
o
C, 18 h, air
CO 2 Me
Cu(OAc)2 H 2 O (1.0 equiv)
N
O
O
N
O
O
CO 2 Me
(a) oxazolidionone DG
RuCl 2( p-cymene) 2 (5.0 mol%)
AgSbF6 (20 mol%)
2-MeTHF, 100
o
C, 18 h, air
CO 2 Et
Cu(OAc)2 H 2 O (1.0 equiv)
N
NH
O
N
NH
O
CO 2 Et
(b) hydantoin DG
O
O
RuCl 2( p-cymene) 2 (5.0 mol%)
AgSbF6 (20 mol%)
2-MeTHF, 120
o
C, 18 h, air
CO 2 Me
Cu(OAc)2 H 2 O (1.0 equiv)
N
O
N
O
CO 2 Me
(c) succinimide DG
O
O
(d)
K 3 PO 4 (2.0 equiv)
2-MeTHF
100
o C, 18 h
Ru(OAc)2 (PPh3)2 (10 mol%)
N
N
N
N
i-pr
t-Bu-Br
N
N
N
N
i-pr
t-Bu
Scheme 44 2-MeTHF as a green solvent for Ru-catalyzed (a) alkenylation of oxazolidinones, (b)
alkenylation of hydantoin, (c) alkenylation of succinimide, (d) alkylation of purines
hydantoins and N-aryl succinimides (Scheme 44b, c). On the other hand,
[Ru(OAc) 2 (PPh 3 ) 2 ] as the catalyst was utilized for meta-selective C–H alkylation of
purines by Ackermann et al. (Scheme 44d) [178].
Insights into Sustainable C–H Bond Activation