Beilstein J. Org. Chem.2010,6, 1091–1098, doi:10.3762/bjoc.6.125
: leaving group, e.g. phosphine or pyridine; olive: carbine substituents; and dashed lines symbolise possibilities of chelation). Three commercial and frequently used catalysts (G2: Grubbs 2nd generation catalyst; M2: Neolyst M2; and 1: Hoveyda 2nd generation catalyst).
Details of the 1H NMR spectra
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Graphical Abstract
Figure 1:
General layout for modifications of ruthenium-based olefin metathesis catalysts (red: anionic ligan...
Beilstein J. Org. Chem.2010,6, No. 59, doi:10.3762/bjoc.6.59
polymerization in comparison to U1. The synthesis of block copolymers with molecular weights up to Mn = 31 000 g/mol with low polydispersities (Mw/Mn = 1.2) is reported.
Keywords: block copolymer (BCP); crossover reaction; MALDI; NEOLYST™; ROMP; Introduction
Block copolymers are macromolecules composed of
lower polydispersities of the resulting polymers.
Recently, structural variations of G1–G3 catalysts generated a new series of catalysts U1–U3 bearing indenyl-carbenes instead of benzylidene-carbenes. These new catalysts are now commercially available and are well known as the Umicore catalysts (NEOLYST
precision and chain length control up to molecular weights of ~31000 g/mol.
Conclusion
The synthesis of new block copolymers containing free radical centers within one block via ROMP has been described. MALDI analyses especially provide a detailed picture of the crossover reaction. Basically, the NEOLYST
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Graphical Abstract
Scheme 1:
Grubbs G1–G3 and Umicore U1–U3 catalyst.