Chemistry Reference
In-Depth Information
1. ROP
AcO
OAC
HO
+
OH
2. hydrolysis
n
OO
O
O
O
H
O
O
3, ROP
O
O
H
2n
O
The product is a terpolymer with a soft midblock component with hard blocks at the end. As a
result the polymer is a strong and tough material.
Ruthenium catalysts are reactive only towards olefins. As a result, it is possible to introduce
functional groups into the monomer prior to polymerizations. This was demonstrated by Hilf and
Kilbinger [
183
] They demonstrated that small ring vinyl lactones and carbonates are efficient
quenchers for the olefin metathesis polymerization. The slow kinetics of the reaction can be overcome
by an excess of the reagent. The rapid termination of the polymerization reaction yields highly
functionalized polymers with narrow molecular weight distribution:
Ph
PCy
3
PCy
3
O
Cl
Cl
Ru
Ru
O
Ph
Cl
Cl
PCy
3
O
PCy
3
PCy
3
O
O
Ph
Cl
O
Ru
Ph
Cl
PCy
3
PCy
3
PCy
3
O
Cl
Cl
Ru
Ru
O
Ph
Cl
Cl
PCy
3
O
PCy
3
O
Metathesis type catalysts can also polymerize substituted acetylenes. This is discussed in Chap.
10
.
A class of olefin metathesis catalysts that contains phosphite ligands has advantages over current
catalysts for some challenging reactions, such as ring-closing metatheses of hindered dienes. Cazin
et al. [
184
] modified an existing ruthenium indenylidene metathesis catalyst with triisopropyl
phosphite groups to form
cis
and
trans
phosphite complexes.
N
N
P(OR)
3
Ru
Cl
Ph
Cl
