scholarly journals Poly(2-ethyl-2-oxazoline-co-N-propylethylene imine)s by controlled partial reduction of poly(2-ethyl-2-oxazoline): Synthesis, characterization and cytotoxicity

2020 ◽  
Author(s):  
Sebastian Halupczok ◽  
Maria Krebs ◽  
Annemarie Ringhand ◽  
Corinna Fetsch ◽  
Alevtina Cubukova ◽  
...  
Keyword(s):  
Lithium Aluminum Hydride ◽  
Direct Reduction ◽  
Aluminum Hydride ◽  
Lithium Aluminum ◽  
Partial Reduction

The partial reduction of poly(2-ethyl-2-oxazoline) was investigated. A series of poly(2-ethyl-2-oxazoline-co-N-propylethylene imine)s were synthesized by direct reduction using lithium aluminum hydride or borane/dimethylsulfide (BH3/DMS), respectively. It is shown that the degree...

The Preparation of Specifically Deuterated trans- Cinnamyl Alcohol and trans- Cinnamic Acid

1973 ◽  
Vol 51 (13) ◽  
pp. 2102-2104 ◽  
Author(s):  
Donald G. Lee ◽  
James R. Brownridge
Keyword(s):  
Cinnamic Acid ◽  
Triple Bond ◽  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Lithium Aluminum ◽  
Cinnamyl Alcohol ◽  
Partial Reduction ◽  
Work Up

The reduction of ethyl phenylpropiolate by lithium aluminum hydride results in partial reduction of the triple bond to give trans-cinnamyl alcohol. If ethyl phenylpropiolate is reduced by LiAlD4 followed by work-up with acetone and H2O the product is the specifically labeled compound, trans-3-phenyl-2-propen-1-ol-1,1,2-d3. If the ester is reduced with LiAlH4 followed by work-up with acetone-d6 and D2O the product is trans-3-phenyl-2-propen-1-ol-O,3-d2. Oxidation of these two products by sodium ruthenate leads to formation of trans-cinnamic acid-α-d and trans-cinnamic acid-β-d, respectively.

Poly(2-ethyl-2-oxazoline-co-N-propylethylene imine)s by controlled partial reduction of poly(2-ethyl-2-oxazoline)

2018 ◽  
Author(s):  
Maria Pfister ◽  
Annemarie Ringhand ◽  
Corinna Fetsch ◽  
Robert Luxenhofer
Keyword(s):  
Glass Transition ◽  
Direct Reduction ◽  
Aluminum Hydride ◽  
Side Chain ◽  
Lithium Aluminum ◽  
Partial Reduction ◽  
Cationic Polymers ◽  
Scanning Calorimetry ◽  
Degree Of Reduction ◽  
Hydrophilic Lipophilic Balance

The partial reduction of poly(2-ethyl-2-oxazoline) was investigated. A series of poly(2-ethyl-2-oxazoline-co-N-propylethylene imine)s were synthesized by direct reduction using lithium aluminum hydride or borane/dimethylsulfide (BH<sub>3</sub>/DMS), respectively. It is shown that the degree of reduction can be readily controlled either by the reaction time when using an excess of LiAlH<sub>4</sub> or by the stoichiometry of BH<sub>3</sub>/DMS as was demonstrated by 1H-NMR spectroscopy. Differential scanning calorimetry revealed that the glass transition temperature of the products decreased with increasing degree of reduction up to 25% of reduction, above which no glass transition could be detected. This control over the reduction allows the tailor synthesis of partially cationic polymers, which, in combination over the hydrophilic/lipophilic balance through the side chain length allows a tight control over materials properties. Such materials may be interesting, <i>inter alia</i>, for biomaterials or organic electronics.

Poly(2-ethyl-2-oxazoline-co-N-propylethylene imine)s by controlled partial reduction of poly(2-ethyl-2-oxazoline)

2018 ◽  
Author(s):  
Maria Pfister ◽  
Annemarie Ringhand ◽  
Corinna Fetsch ◽  
Robert Luxenhofer
Keyword(s):  
Glass Transition ◽  
Direct Reduction ◽  
Aluminum Hydride ◽  
Side Chain ◽  
Lithium Aluminum ◽  
Partial Reduction ◽  
Cationic Polymers ◽  
Scanning Calorimetry ◽  
Degree Of Reduction ◽  
Hydrophilic Lipophilic Balance

The partial reduction of poly(2-ethyl-2-oxazoline) was investigated. A series of poly(2-ethyl-2-oxazoline-co-N-propylethylene imine)s were synthesized by direct reduction using lithium aluminum hydride or borane/dimethylsulfide (BH<sub>3</sub>/DMS), respectively. It is shown that the degree of reduction can be readily controlled either by the reaction time when using an excess of LiAlH<sub>4</sub> or by the stoichiometry of BH<sub>3</sub>/DMS as was demonstrated by 1H-NMR spectroscopy. Differential scanning calorimetry revealed that the glass transition temperature of the products decreased with increasing degree of reduction up to 25% of reduction, above which no glass transition could be detected. This control over the reduction allows the tailor synthesis of partially cationic polymers, which, in combination over the hydrophilic/lipophilic balance through the side chain length allows a tight control over materials properties. Such materials may be interesting, <i>inter alia</i>, for biomaterials or organic electronics.

REDUCTION OF STEROIDS USING LITHIUM ALUMINUM HYDRIDE

1949 ◽  
Vol 27b (12) ◽  
pp. 902-906 ◽  
Author(s):  
G. Papineau-Couture ◽  
Gordon A. Grant ◽  
E. M. Richardson
Keyword(s):  
Carbonyl Group ◽  
Phthalic Anhydride ◽  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Selective Reduction ◽  
Reduction Product ◽  
Lithium Aluminum ◽  
Partial Reduction ◽  
Simultaneous Production

Lithium aluminum hydride has been used successfully in the partial reduction of phthalic anhydride to phthalide, in the selective reduction of the carbonyl group of dehydroisoandrosterone-3-acetate, and in the reduction of oestrone acetate to α-oestradiol without simultaneous production of the β-isomer. A new reduction product of Δ5-3(β)hydroxyetiobilienic acid, Δ9,14-2,13-dimethyl-7(β)hydroxy-2-hydroxymethyl-1-hydroxyethyl dodecahydrophenanthrene, is also described.

Synthesis of Novel Chiral Pyrimidone Salts and their Application in Asymmetric Diethylzinc Addition of Arylaldehydes

2018 ◽  
Vol 15 (1) ◽  
pp. 137-142 ◽  
Author(s):  
Bi-Hui Zhou ◽  
Wei-Ping He ◽  
Lin-Lin Li ◽  
Li-Mei Fan ◽  
Xiang-Rong Li ◽  
...  
Keyword(s):  
Thionyl Chloride ◽  
Lithium Aluminum Hydride ◽  
Secondary Alcohol ◽  
Aluminum Hydride ◽  
Heterocyclic Carbenes ◽  
Ammonium Salts ◽  
Lithium Aluminum ◽  
Partial Reduction ◽  
Subsequent Reaction ◽  
Efficient Route

Aims and Objectives: When compared to five-membered N-heterocyclic carbene, recent reports have demonstrated that ring expanded NHCs showed rather different properties such as increased basicity (nucleophilicity) and greater steric demand. These unique features provide an opportunity to design new chiral ligands. This study was undertaken to design and synthesize a series of novel enantiopure pyrimidone salts, the precursors of N-heterocyclic carbenes, and their activity in asymmetric diethylzinc addition of arylaldehydes was demonstrated as well. Materials and Method: Commercially available dimethylmalonic acid was treated with thionyl chloride to form dimethylmalony dichloride, followed by subsequent reaction with different chiral primary amine produced corresponding diamide. Next, conversion of diamide to monoamide was achieved by partial reduction with lithium aluminum hydride. Finally, cyclization of monoamide with triethyl orthoformate in the presence of ammonium salts provided pyrimidone salts in good yields. Results: Seven enantiopure pyrimidone salts, the precursors of N-heterocyclic carbenes, have been synthesized starting from dimethylmalonic acid. Their applicability in asymmetric diethylzinc addition of arylaldehydes has been demonstrated and the corresponding secondary alcohol was obtained with good yields and moderate enantioselectivities. Conclusion: Herein we developed an efficient route to prepare a series of novel N-heterocyclic carbene precursors, which were demonstrated as effective catalysts for asymmetric diethylzinc addition of arylaldehydes, and the corresponding secondary alcohol was obtained with good yields and moderate enantioselectivities.

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