ChemInform Abstract: TITANATE‐MEDIATED TRANSESTERIFICATIONS WITH FUNCTIONALIZED SUBSTRATES

Seebach, D.; HUNGERBUEHLER, E.; Naef, Reto; Schnurrenberger, P.; Weidmann, Beat; ZUEGER, M.

doi:10.1002/chin.198223149

Cited by 7 publications

(11 citation statements)

References 1 publication

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“…Tetra-n-butyltitanate (Ti(OBu) 4 ) was the catalyst in all experiments, since its activity in the alcoholysis of esters is well-established. [16] To prevent thermal oxidation, Irganox 1330 was used as an antioxidant. The results of the polycondensation reactions are summarized in Table 2.…”

Section: Polymersmentioning

confidence: 99%

“…[16] It seems, therefore, reasonable to assume that both transesterification and diol-promoted carbamate alcoholysis occurred during the polymerization reaction. Moreover, 1 H NMR data indicates that almost half of the PEG in the feed is connected to carboxyl ester groups, thus suggesting that PEG1000 promoted the alcoholysis of carbamate groups.…”

Section: Polymersmentioning

confidence: 99%

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Synthesis and Characterization of Segmented Poly(ether ester)s Containing H‐Bonding Units

Signori

Solaro

Chiellini

et al. 2003

Macro Chemistry & Physics

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A series of poly(ether ester)s containing different H‐bonding units (amide, carbamate, urea) was prepared by polycondensation in bulk, using Ti(OBu)4 as a catalyst. The copolymers were obtained starting from PEG1000, 1,4‐butanediol, and a symmetrical, bis‐ester terminated monomer carrying H‐bonding units. These materials were designed for biomedical applications, in which ultimate biodegradability of the materials is required. The influence of the nature of the H‐bonding unit and of the length of the methylene spacer between H‐bonding groups on the thermal and solubility properties of copolymers was investigated. Amide containing copolymers were more thermally stable than ones containing carbamate, consistent with the observed behavior of the corresponding monomers. In most cases, differential scanning calorimetry (DSC) traces were quite complex because of phase separation and dependent on the applied cooling rate. Copolymers containing urea bonds were less soluble in most organic solvents, but their thermal properties were not significantly different than their amide containing counterparts.

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Section: Polymersmentioning

confidence: 99%

Section: Polymersmentioning

confidence: 99%

Synthesis and Characterization of Segmented Poly(ether ester)s Containing H‐Bonding Units

Signori

Solaro

Chiellini

et al. 2003

Macro Chemistry & Physics

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“…During polymerization, the temperature was progressively increased from room temperature up to the final set value, whereas the pressure was progressively decreased to 0.1 mbar in order to facilitate the removal of volatile polycondensation products. Tetrabutyl titanate [Ti(OBu) 4 ] was selected as the catalyst in all experiments, since its activity as condensation promoter of esters with alcohols is well established 16. Moreover, to prevent PEG1000 from thermal oxidation, 1% by weight of Irganox 1330 was used in all cases as an antioxidant.…”

Section: Resultsmentioning

confidence: 99%

Segmented Multifunctional Poly(ether ester) Polymers Containing H‐Bonding Units. Preparation and Characterization

Signori

Solaro

Lips

et al. 2004

Macro Chemistry & Physics

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Summary: A series of poly(ether ester)s containing amide and carbamate groups as H‐bonding units and 13–50 mol‐% of poly(ethylene glycol) (PEG) segments were prepared by polycondensation in bulk using Ti(OBu)4 as a catalyst. The copolymers were obtained starting from PEG/1,4‐butanediol mixtures and a synthetic monomer carrying H‐bonding groups. These polymers were designed for biomedical applications, where material biodegradability is required. The influence of the nature of the H‐bonding units, the length of the polymethylene spacer between the H‐bonding groups and the PEG content on the thermal and solubility properties of the copolymers was investigated. Amide‐containing copolymers were more thermally stable than those containing carbamate groups. The PEG content also slightly affected the polymer thermal stability. The DSC traces of all samples presented multiple transitions, whose shape and peak temperature were strongly dependent on the PEG content. Polymer hydrophilicity, surface free energy and equilibrium swelling in phosphate buffer solution (PBS) at 37 °C were mainly influenced by the PEG content, whereas the nature of the H‐bonding groups had little effect.

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“…10 Thus, treatment of 12 with (À)-menthol (1.5 eq) in the presence of a catalytic amount of titanium (IV) ethoxide (15 mol%) in xylene at 80 C provided (À)-menthyl ester 13 in 79% yield. The reaction was pushed to completion by distillation of the ethanol generated by passing a stream of nitrogen through the reaction vessel.…”

Section: Preparation Of Diol 9 Coupling Partnermentioning

confidence: 99%

Development of an Asymmetric Synthesis of ABT‐100

Kruger

Rozema

Rohde

et al. 2006

Fundamentals of Early Clinical Drug Development

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ChemInform Abstract: TITANATE‐MEDIATED TRANSESTERIFICATIONS WITH FUNCTIONALIZED SUBSTRATES

Abstract: Zahlreiche funktionelle Gruppen enthaltende Ester (I) werden mit Hilfe von Titan(IV)‐alkoxiden in bekannter Weise umgeestert.

Cited by 7 publications

References 1 publication

Synthesis and Characterization of Segmented Poly(ether ester)s Containing H‐Bonding Units

Synthesis and Characterization of Segmented Poly(ether ester)s Containing H‐Bonding Units

Segmented Multifunctional Poly(ether ester) Polymers Containing H‐Bonding Units. Preparation and Characterization

Development of an Asymmetric Synthesis of ABT‐100

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