N-Acyl glycinates as acyl donors in serine protease-catalyzed kinetic resolution of amines. Improvement of selectivity and reaction rate

2008 ◽  
Vol 6 (21) ◽  
pp. 3917 ◽  
Author(s):  
Malek Nechab ◽  
Lahssen El Blidi ◽  
Nicolas Vanthuyne ◽  
Stéphane Gastaldi ◽  
Michèle P. Bertrand ◽  
...  
Keyword(s):  
Serine Protease ◽  
Reaction Rate ◽  
Kinetic Resolution ◽  
Acyl Donors

scholarly journals Enantioselective Transesterification of Allyl Alcohols with (E)-4-Arylbut-3-en-2-ol Motif by Immobilized Lecitase™ Ultra

Catalysts ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 798
Author(s):  
Aleksandra Leśniarek ◽  
Anna Chojnacka ◽  
Radosław Drozd ◽  
Magdalena Szymańska ◽  
Witold Gładkowski
Keyword(s):  
High Activity ◽  
Cyanogen Bromide ◽  
Kinetic Resolution ◽  
Negative Effects ◽  
Subsequent Reaction ◽  
Wide Range ◽  
Allyl Alcohols ◽  
Reaction Cycles ◽  
Acyl Donors ◽  
First Time

Lecitase™ Ultra was immobilized on four different supports and tested for the first time as the biocatalyst in the kinetic resolution of racemic allyl alcohols with the (E)-4-arylbut-3-en-2-ol system in the process of transesterification. The most effective biocatalyst turned out to be the enzyme immobilized on agarose activated with cyanogen bromide (LU-CNBr). The best results (E > 200, ees and eep = 95–99%) were obtained for (E)-4-phenylbut-3-en-2-ol and its analog with a 2,5-dimethylphenyl ring whereas the lowest ee of kinetic resolution products (90%) was achieved for the substrate with a 4-methoxyphenyl substituent. For all substrates, (R)-enantiomers were esterified faster than their (S)-antipodes. The results showed that LU-CNBr is a versatile biocatalyst, showing high activity and enantioselectivity in a wide range of organic solvents in the presence of commonly used acyl donors. High operational stability of LU-CNBr allows it to be reused in three subsequent reaction cycles without negative effects on the efficiency and enantioselectivity of transesterification. This biocatalyst can become attractive to the commercial lipases in the process of the kinetic resolution of allyl alcohols.

scholarly journals Development of dynamic kinetic resolution on large scale for (±)-1-phenylethylamine

2010 ◽  
Vol 6 ◽  
pp. 823-829 ◽  
Author(s):  
Lisa K Thalén ◽  
Jan-E Bäckvall
Keyword(s):  
Good Yield ◽  
Large Scale ◽  
Kinetic Resolution ◽  
Catalyst Loading ◽  
Acyl Donor ◽  
Dynamic Kinetic Resolution ◽  
Reaction Parameters ◽  
Ru Catalyst ◽  
Isopropyl Acetate ◽  
Acyl Donors

Candida antarctica lipase B (CALB) and racemization catalyst 4 were combined in the dynamic kinetic resolution (DKR) of (±)-1-phenylethylamine (1). Several reaction parameters have been investigated to modify the method for application on multigram scale. A comparison of isopropyl acetate and alkyl methoxyacetates as acyl donors was carried out. It was found that lower catalyst loadings could be used to obtain (R)-2-methoxy-N-(1-phenylethyl)acetamide (3) in good yield and high ee when alkyl methoxyacetates were used as acyl donors compared to when isopropyl acetate was used as the acyl donor. The catalyst loading could be decreased to 1.25 mol % Ru-catalyst 4 and 10 mg CALB per mmol 1 when alkyl methoxyacetates were used as the acyl donor.

Highly Selective Enzymatic Kinetic Resolution of Primary Amines at 80 °C:  A Comparative Study of Carboxylic Acids and Their Ethyl Esters as Acyl Donors

2007 ◽  
Vol 72 (18) ◽  
pp. 6918-6923 ◽  
Author(s):  
Malek Nechab ◽  
Nadia Azzi ◽  
Nicolas Vanthuyne ◽  
Michèle Bertrand ◽  
Stéphane Gastaldi ◽  
...  
Keyword(s):  
Comparative Study ◽  
Carboxylic Acids ◽  
Kinetic Resolution ◽  
Ethyl Esters ◽  
Primary Amines ◽  
Enzymatic Kinetic Resolution ◽  
Acyl Donors

scholarly journals Transient Operation: A Catalytic Chemoselective Hydrogenation of 2-Methyl-3-Butyn-2-ol via a Cooperative Pd and Radiofrequency Heating Directed Kinetic Resolution

Catalysts ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 283 ◽  
Author(s):  
Duaa Raja ◽  
Jabbar Gardy ◽  
Ali Hassanpour ◽  
Chun-Yu Ho ◽  
Javier Fernandez Garcia
Keyword(s):  
Reaction Rate ◽  
Kinetic Resolution ◽  
Temperature Cycling ◽  
Production Scale ◽  
Temperature Oscillations ◽  
Chemoselective Hydrogenation ◽  
Steady State Operation ◽  
Starting Point ◽  
Radiofrequency Heating ◽  
Periodic Temperature

The effect of periodic temperature oscillations has been studied for the hydrogenation of 2-methyl-3-butyn-2-ol over a Pd-based catalyst in a micro-trickle bed reactor. This hydrogenation was investigated using a radiofrequency heated reactor under transient conditions using temperature cycling. The dynamic operation using this configuration was found to increase both conversion and selectivity towards 2-methyl-3-buten-2-ol compared to the steady-state operation with an improvement of up to 24% for the selectivity being observed. The developments made here also result in a lower activation energy in comparison to previous data, providing a starting point for radiofrequency heating to enhance reaction rate through the exploitation of thermal cycling at production scale.

Water content influences the selectivity of CALB-catalyzed kinetic resolution of phenoxymethyl-substituted secondary alcohols

2002 ◽  
Vol 80 (6) ◽  
pp. 577-581 ◽  
Author(s):  
Elisabeth Egholm Jacobsen ◽  
Thorleif Anthonsen
Keyword(s):  
Water Content ◽  
Water Activity ◽  
Kinetic Resolution ◽  
Relative Rate ◽  
High Water ◽  
High Water Content ◽  
Acyl Donor ◽  
Acyl Donors ◽  
Reaction Media ◽  
Derivatives Of

Derivatives of 1-phenoxy-2-alkanols were kinetically resolved by esterification with irreversible and reversible acyl donors using lipase B from Candida antarctica (Novozyme 435) as a catalyst. To optimize the relative rate of reaction (the E-value), esterifications in eight different solvents with different water activities were performed. For 3-bromo-1-phenoxy-2-propanol (1), the E-values in all the solvents were higher when the water activity was increased, while the E-values for 1-phenoxy-2-pentanol (2) and 3-chloro-1-phenoxy-2-propanol (3) decreased by increasing water activity. The water content of the various reaction media with the same water activity was determined. Solvents such as 1,4-dioxane, acetonitrile, and tetrahydrofuran contained much more water than hexane, carbon tetrachloride, cyclohexane, toluene, and benzene. At high-water activity, the high-water content of the former group of solvents resulted in termination of the reaction at low conversion. The reason seemed to be that the acyl donor and possibly also the produced esters were hydrolyzed. This was not the case when the esterification was performed in water-immiscible solvents with the same water activity.Key words: kinetic resolution, E-value, solvents, water activity, water content.

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