ja308620h_si_001.pdf (3.07 MB)
Tandem Catalysis for the Preparation of Cylindrical Polypeptide Brushes
journal contribution
posted on 2012-11-28, 00:00 authored by Allison
J. Rhodes, Timothy J. DemingHere, we report a method for synthesis of cylindrical
copolypeptide
brushes via N-carboxyanhydride (NCA) polymerization
utilizing a new tandem catalysis approach that allows preparation
of brushes with controlled segment lengths in a straightforward, one-pot
procedure requiring no intermediate isolation or purification steps.
To obtain high-density brush copolypeptides, we used a “grafting
from” approach where alloc-α-aminoamide groups were installed
onto the side chains of NCAs to serve as masked initiators. These
groups were inert during cobalt-initiated NCA polymerization and gave
allyloxycarbonyl-α-aminoamide-substituted polypeptide main chains.
The alloc-α-aminoamide groups were then activated in
situ using nickel to generate initiators for growth of side-chain
brush segments. This use of stepwise tandem cobalt and nickel catalysis
was found to be an efficient method for preparation of high-chain-density,
cylindrical copolypeptide brushes, where both the main chains and
side chains can be prepared with controlled segment lengths.