Some recent applications of 13C NMR spectroscopy to the study of the ring-opening polymerization of cycloalkenes and related reactions initiated by metathesis catalysts

The aim of this paper is to present a synthesis method of poly(ε-caprolactone) by the ring opening polymerization of ε-caprolactone catalyzed with nontoxic magnesium lactate. The results indicated that Mg(Lac)2 is a catalyst with moderate activity for the polymerization of ε-caprolactone. Effects of the catalyst and reaction temperatures on the microstructure of the ε-caprolactone and L-lactide copolymers were investigated by means of 13C-NMR spectroscopy. An increase in the reaction temperature enhances the role of transesterification and the extent of randomness.

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SYNTHESIS AND NMR ANALYSIS OF THE STRUCTURE AND COMPOSITION OF TRIBLOCK POLY(ESTER-SILOXANE-ESTER) COPOLYMER BASED ON L-LACTIDE

Contemporary Materials ◽

10.7251/comen1701033b ◽

2017 ◽

Vol 8 (1) ◽

Author(s):

Milica Balaban ◽

Nataša Sladojević ◽

Vesna Antić

Keyword(s):

Nmr Spectroscopy ◽

Ring Opening ◽

13C Nmr Spectroscopy ◽

Ring Opening Polymerization ◽

Dilute Solution ◽

Nmr Analysis ◽

1H And 13C Nmr ◽

Influence Of Temperature ◽

Dimethyl Siloxane ◽

Dilute Solution Viscometry

The synthesis, structure and composition of triblock poly(ester-siloxane-ester) copolymers, PLLA-PDMS-PLLA, based on α,ω–diaminopropyl-poly(dimethyl siloxane) (PDMS) and L-lactide were studied in this work. The samples of the controlled block length were synthesized by ring-opening polymerization of L-lactide in the presence of stannous octoate, Sn(Oct)2, as a catalyst, and aminopropyl-terminated siloxane prepolymer, as a macroinitiator, in a concentrated toluene solution. Influence of temperature and concentration of the catalyst on the structure, composition and size of the copolymers were investigated by 1H and 13C NMR spectroscopy and dilute solution viscometry.

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1-Tosyl-6-vinyl-4,5,6,7-tetrahydro-1H-benzo [d] imidazole-2-amine

Molbank ◽

10.3390/m1262 ◽

2021 ◽

Vol 2021 (3) ◽

pp. M1262

Author(s):

Fiach B. Meany ◽

Sarah O’Rourke ◽

Paul V. Murphy

Keyword(s):

Natural Products ◽

Nmr Spectroscopy ◽

1H Nmr ◽

13C Nmr ◽

Title Compound ◽

Ring Opening ◽

13C Nmr Spectroscopy ◽

Amino Alcohols ◽

Epoxide Ring ◽

Epoxide Ring Opening

The alkene functionalised 2-aminobenzimidazole ring found in terrazoanthine natural products was synthesized in 3 steps from 1,2-epoxy-4-vinylcyclohexane via epoxide ring opening with toluenesulphonamide yielding 2 regioisomeric, separable amino alcohols. One isomer was oxidized to the corresponding ketone and subsequently condensed with cyanamide to furnish the title compound, which was characterized by 1H-NMR and 13C-NMR spectroscopy.

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(2S,3R,6R)-2-[(R)-1-Hydroxyallyl]-4,4-dimethoxy-6-methyltetrahydro-2H-pyran-3-ol

Molbank ◽

10.3390/m1140 ◽

2020 ◽

Vol 2020 (2) ◽

pp. M1140

Author(s):

Jack Bennett ◽

Paul Murphy

Keyword(s):

Mass Spectrometry ◽

Nmr Spectroscopy ◽

Ir Spectroscopy ◽

13C Nmr ◽

Conjugate Addition ◽

13C Nmr Spectroscopy ◽

One Pot ◽

1H And 13C Nmr ◽

Esi Mass Spectrometry ◽

The One

(2S,3R,6R)-2-[(R)-1-Hydroxyallyl]-4,4-dimethoxy-6-methyltetrahydro-2H-pyran-3-ol was isolated in 18% after treating the glucose derived (5R,6S,7R)-5,6,7-tris[(triethylsilyl)oxy]nona-1,8-dien-4-one with (1S)-(+)-10-camphorsulfonic acid (CSA). The one-pot formation of the title compound involved triethylsilyl (TES) removal, alkene isomerization, intramolecular conjugate addition and ketal formation. The compound was characterized by 1H and 13C NMR spectroscopy, ESI mass spectrometry and IR spectroscopy. NMR spectroscopy was used to establish the product structure, including the conformation of its tetrahydropyran ring.

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