Introduction to Enzyme and Coenzyme Chemistry - E-Library Home

Non-Enzymatic Biological Catalysis 265
Hapten
Antibody catalyses 6-endo-tet epoxide cyclisation:
HO
− O
O
R
N
+
R
HO
R
O
PhMe 2 Si
N+
H
N
O
O
Hapten
R
O
R = CH 3 or O −
N
H
NH-protein
Antibody catalyses expected cyclisation of silyl-substituted sulphonate substrate....
SiMe 2 Ph
SiMe 2 Ph
SiMe 2 Ph
+
OH
+
O
O
S
O
90% 10%
Ar
....and the unexpected cyclopropanation of an alkyl-substituted substrate:
CMe 2 Ph
O
O
S
O
PhMe 2 C
H
+ CH 3
H
H
CMe 2 Ph
H
CH 3
H
Ar
Figure 12.12 Antibody catalysis of cyclisation reactions.
12.4 Synthetic enzyme models
One of the Wnal frontiers in biological chemistry is the design of synthetic
models for biological catalysis. Can we design and synthesise small or
medium-sized molecules which mimic enzymes
First of all we need to deWne what requirements we need of such a model, as
follows: