24

Aromatic Radical Arylation

Effect of substituents on radical substitution is very slight. Only nitro and cyano
groups exhibit a profound effect and thus become para and ortho directing in contrast
to electrophilic substituion reactions. This also limits the usefulness of radical
methods quite considerably.

Meerwein Arylation

5.2.

Related Reactions

Heck Coupling, Suzuki Coupling,

6.

Introduction to 1H-NMR Spectroscopy

6.1.

General

•
•

The proton has spin quantum number I = 1/2.
In a magnetic field it each proton possesses 2I+1 spin states i.e. 2, +1/2 and -1/2.
Only in a magnetic field is this degeneracy lifted (Zeeman effect)

B

∆E

1H-NMR spectroscopy measures this difference in energy.

υ= γx B0/2πwith γ= μz/Izand E = hν
γ= gyromagnetic ratio
μz= nuclear magnetic dipole in the z direction
Iz= angular momentum for a given nucleus in the z direction

I

CuO2C

O

O

heat

+

X

+

Y

X

Y

X

Y

Cu(II)

+

X

Y

+

Cu(I)

X

Y

X

Y

Cl

Cl-

Br

O

+

hν

NH3

O

Br

Br

Br-

+