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

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.

Ring Opening Polymerization of ε-Caprolactone Catalyzed with Magnesium Lactate

2009 ◽  
Vol 610-613 ◽  
pp. 1208-1210 ◽  
Author(s):  
Lian Liu ◽  
Zhi Yong Wei ◽  
Pei Wang ◽  
Min Qi
Keyword(s):  
Nmr Spectroscopy ◽  
Reaction Temperature ◽  
13C Nmr ◽  
Ring Opening ◽  
Synthesis Method ◽  
13C Nmr Spectroscopy ◽  
Ring Opening Polymerization ◽  
Moderate Activity ◽  
Lactide Copolymers

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.

scholarly journals Ring-Opening Polymerization of ε-Caprolactone and Styrene Oxide–CO2 Coupling Reactions Catalyzed by Chelated Dehydroacetic Acid–Imine Aluminum Complexes

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 164
Author(s):  
Ting-Yen Wang ◽  
Yu-Chia Su ◽  
Bao-Tsan Ko ◽  
Yu Hsu ◽  
Yu-Fang Zeng ◽  
...  
Keyword(s):  
Ring Opening ◽  
Styrene Oxide ◽  
13C Nmr Spectroscopy ◽  
Ring Opening Polymerization ◽  
Coupling Reactions ◽  
1H And 13C Nmr ◽  
Excess Carbon ◽  
Catalytic Activities ◽  
Dehydroacetic Acid ◽  
Aluminum Compounds

A series of chelated dehydroacetic acid–imine-based ligands L1H~L4H was synthesized by reacting dehydroacetic acid with 2-t-butylaniline, (S)-1-phenyl-ethylamine, 4-methoxylbenzylamine, and 2-(aminoethyl)pyridine, respectively, in moderate yields. Ligands L1H~L4H reacted with AlMe3 in toluene to afford corresponding compounds AlMe2L1 (1), AlMe2L2 (2), AlMe2L3 (3), and AlMe2L4 (4). All the ligands and aluminum compounds were characterized by IR spectra, 1H and 13C NMR spectroscopy. Additionally, the ligands L1H~L4H and corresponding aluminum derivatives 1, 3, and 4 were characterized by single-crystal X-ray diffractometry. The catalytic activities using these aluminum compounds as catalysts for the ε-caprolactone ring-opening polymerization (ROP) and styrene oxide-CO2 coupling reactions were studied. The results show that increases in the reaction temperature and selective solvent intensify the conversions of ε-caprolactone to polycaprolactone. Regarding the coupling reactions of styrene oxide and CO2, the conversion rate is over 90% for a period of 12 h at 90 °C. This strategy dispenses the origination of cyclic styrene carbonates, which is an appealing concern because of the transformation of CO2 into an inexpensive, renewable and easy excess carbon feedstock.

scholarly journals (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.

scholarly journals Experimental and Computational Studies on N-alkylation Reaction of N-Benzoyl 5-(Aminomethyl)Tetrazole

Chemistry ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 704-713
Author(s):  
Younas Aouine ◽  
Aaziz Jmiai ◽  
Anouar Alami ◽  
Abdallah El Asri ◽  
Souad El Issami ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Nmr Spectroscopy ◽  
Density Functional ◽  
Computational Study ◽  
Benzyl Bromide ◽  
13C Nmr Spectroscopy ◽  
Alkylation Reaction ◽  
Computational Studies ◽  
Functional Theory ◽  
1H And 13C Nmr

The N-alkylation reaction of N-benzoyl 5-(aminomethyl)tetrazole (5-AMT) with benzyl bromide was carried out in the presence of K2CO3 as a base. Two separable regioisomers were obtained, thus their purification led to determine the proportion of each of them, and their structures were attributed essentially based on 1H and 13C NMR spectroscopy in addition to the elemental analysis and MS data. In order to confirm the results obtained at the synthesis level, a computational study was carried out by application of density functional theory (DFT) using the Becke three-parameter hybrid exchange functional and the Lee-Yang-Parr correlation functional (B3LYP).

scholarly journals NEW PHARMACOLOGICALLY ACTIVE COMPOUNDS BASED ON 5-HYDROXY-7-METHOXY-2-PHENYLCHROMAN-4-ONE

2021 ◽  
Vol 3 ◽  
pp. 119-127
Author(s):  
G.M. Baisarov ◽  
◽  
S.M. Adekenov ◽  
Keyword(s):  
Nmr Spectroscopy ◽  
13C Nmr ◽  
Potassium Carbonate ◽  
13C Nmr Spectroscopy ◽  
1H And 13C Nmr ◽  
Pharmacologically Active ◽  
Pharmacologically Active Compounds ◽  
First Time

The reaction of 5-hydroxy-7-methoxy-2-phenylchroman-4-one with dibromoalkanes in acetone in the presence of potassium carbonate proceeds according to the Michael’s retro-reaction O-alkylation and leads to the formation of the corresponding 2-(bromo-alkoxy) chalcones. The structure of the synthesized compounds was confirmed by IR-, 1H- and 13C-NMR spectroscopy. The cytotoxic, hepatoprotective and anti-inflammatory effects of chalcone derivatives (2-3) were studied for the first time in vitro and in vivo.

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