Base catalyzed racemization of amino acid derivatives

D’Arrigo, Paola; Arosio, Dario; Cerioli, Lorenzo; Moscatelli, Davide; Servi, Stefano De; Viani, Fiorenza; Tessaro, Davide

doi:10.1016/j.tetasy.2011.05.005

Cited by 16 publications

(17 citation statements)

References 45 publications

(45 reference statements)

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“…This is dynamic kinetic resolution and is one of the situations in which racemisation is desirable . If working with amino acids, efficiently racemising derivatives include: hydantoins, oxazolones and thioesters . The topic has been reviewed elsewhere and here a few of the more recent and relevant publications are described, particularly those that have sought to understand the racemisation process.…”

Section: Kinetics and Mechanisms Of Racemisationmentioning

confidence: 99%

“…In a combined experimental and computational study, the computed deprotonation energies of N ‐protected thioester amino acid derivatives 28 a – h were compared with the measured rates of racemisation in [D 6 ]DMSO/CD 3 OD (5:1, v / v ) . The base in this case was 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) present at 0.5 equivalents.…”

Section: Kinetics and Mechanisms Of Racemisationmentioning

confidence: 99%

“…CD has been successfully applied to measure the racemisation of several systems . Analogous to CD spectroscopy, the process of racemization can also be monitored by using the rotation of plane‐polarized light by using polarimeters and measuring, for example, the optical rotatory power [ α ] D …”

Section: Techniques For Studying Racemisation and Kinetic Datamentioning

confidence: 99%

“…Semiempirical AM1 calculations were used to understand the racemisation in acetonitrile of two chiral ketones, 62 and 63 (Figure ) . The aforementioned studies by Servi and co‐workers and by Zeng and co‐workers correlate the rate constants for racemisation of amino acids with experimental rate constants . However, these computational studies provide correlations strictly within compound classes.…”

Section: Tools To Understand and Predict Racemisation Ratesmentioning

confidence: 99%

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Racemisation in Chemistry and Biology

Ballard

Narduolo

Ahmed

et al. 2020

Chemistry A European J

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The two enantiomers of a compound often have profoundly different biological properties and thus their liability to racemisation in aqueous solutions is an important piece of information. The authors reviewed the available data concerning the process of racemisation in vivo, in the presence of biological molecules (e.g., racemase enzymes, serum albumin, cofactors and derivatives) and under purely chemical but aqueous conditions (acid, base and other aqueous systems). Mechanistic studies are described critically in light of reported kinetic data. The types of experimental measurement that can be used to effectively determine rate constants of racemisation in various conditions are discussed and the data they provide is summarised. The proposed origins of enzymatic racemisation are presented and suggest ways to promote the process that are different from processes taking place in bulk water. Experimental and computational studies that provide understanding and quantitative predictions of racemisation risk are also presented.

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Section: Kinetics and Mechanisms Of Racemisationmentioning

confidence: 99%

Section: Kinetics and Mechanisms Of Racemisationmentioning

confidence: 99%

Section: Techniques For Studying Racemisation and Kinetic Datamentioning

confidence: 99%

Section: Tools To Understand and Predict Racemisation Ratesmentioning

confidence: 99%

See 2 more Smart Citations

Racemisation in Chemistry and Biology

Ballard

Narduolo

Ahmed

et al. 2020

Chemistry A European J

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“…In the development of an industrial resolution procedure, the racemization of the unwanted enantiomer often presents as one of the most difficult obstacles, which require harsh conditions, leading to product decomposition . The racemization of amino acids and their derivatives mainly involves thermal racemization, base‐catalyzed racemization, acid‐catalyzed racemization, and enzyme‐catalyzed racemization . Thermal racemization is a very common method because of its operational simplicity and low cost, especially in industrial applications.…”

Section: Introductionmentioning

confidence: 99%

Efficient racemization of N‐phenylacetyl‐D‐glufosinate for L‐glufosinate production

Xue

et al. 2019

Chirality

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Most amino acids contain chiral centres and exist as both D‐enantiomer and L‐enantiomer. The optically pure enantiomer is often more valuable than the racemate. Enzymatic resolution provides an effective strategy to obtain optically pure amino acids but often results in large amounts of unwanted isomer. In this study, optically pure L‐glufosinate (L‐PPT) was obtained by coupling amidase‐mediated hydrolysis of N‐phenylacetyl‐D,L‐glufosinate with racemization of N‐phenylacetyl‐D‐glufosinate (NPDG), which exclusively exhibits effective herbicidal properties compared with its D‐enantiomer. To improve the yield of L‐PPT, the racemization reaction conditions were optimized, and through single‐factor experiments, the optimal reaction temperature, reaction time, and mole ratio of phenylacetic acid to NPDG were determined to be 150°C, 30 minutes, and 1.5, respectively. The response surface methodology was applied to further optimize the racemization conditions, and the final yield of L‐PPT reached 96.13% with optimum reaction temperature of 154°C, reaction time of 23 minutes, and phenylacetic acid/NPDG mole ratio of 1.7, respectively. Moreover, adding a small amount of acetic anhydride further raised the yield of L‐PPT to 97.02%.

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Racemizable Acyl Donors for Enzymatic Dynamic Kinetic Resolution

Tessaro

2014

Cascade Biocatalysis

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Base catalyzed racemization of amino acid derivatives

Cited by 16 publications

References 45 publications

Racemisation in Chemistry and Biology

Racemisation in Chemistry and Biology

Efficient racemization of N‐phenylacetyl‐D‐glufosinate for L‐glufosinate production

Racemizable Acyl Donors for Enzymatic Dynamic Kinetic Resolution

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