107
+
2 equiv TBPB
120 °C, air
up to 95% yields
X
O
Ar
Ar
OH
H
Ar
O
X
Ar
O
X = C, O
large exess
O
O
O
O
O
O
O
O
95%
O
O
63%
4 3%
70%
O
O
O
80%
MeO
OMe
O
O
O
70%
F
F
O
O
O
78%
Br
Br
Scheme 4.15 Oxidative radical coupling between simple ethers and a, a-diaryl allylic alcohols
TBPB
O
O
O
O
OH
OH
O
O
OH
O
O
OH
O
O
O
O
O
TBPB
Scheme 4.16 Proposed mechanism for oxidative radical coupling
4 Oxidative Radical Couplings