294
coupling reaction involving heteroarene–amine–aldehyde/ketone (Scheme 75). The
synthesized amine tethered azole derivatives bearing alkylamine chain at C2 position are considered as privileged substructure found in natural products possessing
antibiotic action.
1) LiOtBu (2 equiv)
CuI (50 mol%), 10 min
2) Pd(OAc)2 (5 mol%)
ArI (3 equiv)
DMF
MW, 120
o C, 4 h
N
N
O
Bn
S
N
N
N
O
Bn
S
N
Ar
Ar
Scheme 70 Microwave-assisted C–H arylation reaction of thiazolo[5,4-f]quinazolin-9(8h)-one
and aryl iodides
1) LiOtBu (2 equiv)
CuI (50 mol%), 10 min
2) Pd(OAc) 2 (5 mol%)
PPh 3 or PCy 3 (10 mol%)
(Het)ArBr (2 equiv)
or
NiXantphos (10 mol%)
(Het)ArCl (2 equiv)
DMF
MW, 120
o C, 30 min
N
N
O
Bn
N
N
O
Bn
Het
Scheme 71 C2–H arylation reaction of N-3-substituted quinazolin-4(3H)-ones and (hetero)aryl
chlorides
Pd(OAc)2 (0.1 equiv)
PPh3 (0.2 equiv)
AgOAc (3 equiv)
toluene (0.04 M)
MW, 150
o C
N
O
N
R 2
N
O
N
R 2
I
R 1
R 1
Scheme 72 Palladium-catalysed direct C-5–H arylation of 1,2,4-oxadiazoles with aryl iodides
Pd(OAc) 2 (5 mol%)
Ag 3 PO 4 (50 mol%)
ArI (3 equiv)
AcOH (30 equiv)
H 2 O (40 equiv)
MW, 180
o C, 50 min
N
R 1
O
N
R 1
O
R 2
Scheme 73 Pd-catalysed site-specific C-8 arylation/reduction of quinoline N-oxides with
aryl halides
D. S. Deshmukh et al.