Investigation of cationic ring-opening polymerization of 2-oxazolines in the “green” solvent dihydrolevoglucosenone

• Solomiia Borova and
• Robert Luxenhofer

Beilstein J. Org. Chem. 2023, 19, 217–230, doi:10.3762/bjoc.19.21

• polymerization process. Further work will be necessary to establish whether a living polymerization can be achieved by additional adjustments. Keywords: 2-alkyl-2-oxazolines; matrix-assisted laser desorption/ionization mass spectrometry; nuclear magnetic resonance; polymerization kinetics; Introduction

• polymerization of MeOx, there was no improvement when the initiator salt EtOxMeOTf was introduced directly. The molar mass of the resulting PMeOx remained much lower than expected with a broad molar mass distribution. The comparison of the polymerization kinetics using MeOTf and EtOxMeOTf requires a comparison

Methylenelactide: vinyl polymerization and spatial reactivity effects

• Judita Britner and
• Helmut Ritter

Beilstein J. Org. Chem. 2016, 12, 2378–2389, doi:10.3762/bjoc.12.232

•  1). Since the polymerization kinetics are mainly controlled by steric effects and the polarity of the double bonds, we evaluated the electronic structure of the different monomers via 1H nuclear magnetic resonance (NMR) spectroscopy. As expected, the double bond protons of MLA at 5.77 and 5.56 ppm

• polymerization kinetics of MLA are similar to these of MMA. In contrast, the non-cyclic push–pull type monomers MAA and EAA are both less reactive. This indicates that in addition to steric hindrance, the mobility of the substituents plays an important role in the spatially controlled chain growth reactions. The

• electron densities of the vinyl groups of the used monomers play a minor role with respect to the polymerization kinetics. The higher mobility of the free substituents of the non-cyclic push–pull type monomers MAA and EAA causes a reduced polymerization rate (Figure 1) compared to that of the stiff cyclic

Synthesis and crossover reaction of TEMPO containing block copolymer via ROMP

• Olubummo Adekunle,
• Susanne Tanner and
• Wolfgang H. Binder

Beilstein J. Org. Chem. 2010, 6, No. 59, doi:10.3762/bjoc.6.59

•  = tricyclohexylphosphine), [(H2IMes)(PCy3)Cl2Ru(3-phenylinden-1-ylidene)] U2 (H2IMes = 1,3-bis(mesityl)-2-imidazolidinylidene), [(H2IMes)(py)Cl2Ru(3-phenylinden-1-ylidene)] U3 (py = pyridine or 3-bromopyridine) via ring opening polymerization (ROMP). The crossover reaction and the polymerization kinetics were investigated

• (the polymerization reaction is complete after ~20 seconds) whereas the polymerization initiated with catalyst U1 takes significantly longer and never yields significant amounts of the homopolymer (yield < 10 %). As the polymerization kinetics of 7 using catalyst U3 could not be monitored effectively

• spectra were recorded on a Varian Gemini 400 MHz FT-NMR spectrometer, and MestRec (4.9.9.9) was used for data interpretation. The polymerization kinetics of the polymerization reactions with both catalysts U1 and U3 were measured at 25 °C on a 200 MHz FT-NMR spectrometer using CDCl3 as a solvent. GPC

Ring opening metathesis polymerization-derived block copolymers bearing chelating ligands: synthesis, metal immobilization and use in hydroformylation under micellar conditions

• Gajanan M. Pawar,
• Jochen Weckesser,
• Siegfried Blechert and
• Michael R. Buchmeiser

Beilstein J. Org. Chem. 2010, 6, No. 28, doi:10.3762/bjoc.6.28

• triphenylphosphite. Synthesis of M2. Synthesis of poly(M1-b-M2) and of the micellar catalyst poly(M1-b-M2)-Rh. Results for the hydroformylation of 1-octenea. Supporting Information Supporting Information contains polymerization kinetics of M1 by the action of Mo(N-2,6-Me2 C6H3)(CHCMe2Ph)(OCMe(CF3)2)2, GPC-traces