The Application of Two-Phase Catalytic System in Enantioselective Separation of Racemic (R,S)-1-Phenylethanol
Round 1
Reviewer 1 Report
In this study, the enantioselective biotransformation of (R, S)-1-phenylethanol were performed with the use of various catalytic systems containing ionic liquids and n-heptane or toluene as reaction medium. The biotransformation process allows to obtain enantiomerically pure 1-phenylethyl acetate. However, many studies on the resolution of 1-phenylethanol in ionic liquids using lipase have been reported, and this manuscript lacks innovation. In addition, the following aspects of the manuscript need to be revised.
1. The title of the paper is not suitable. It does not indicate what the chemical substance to separate. The order of keywords is also incorrect, racemic 1-phenylethanol should be placed first.
2. The abstract is too simple, and it does not provide the data from the research results. For example, the composition of reaction medium, reaction conditions and the enantiomerically purity of 1-phenylethyl acetate obtained should be presented.
3. Too many points in the manuscript do not meet to the writing requirements of a scientific paper. The author should revise them according to the format requirements of "catalyst". In particular, the formation of figures and tables. For example, Figure 4 has no title in the Y-axis.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
The submitted paper describe lipases as biocatalysts can be used for kinetic resolution of secondary alcohols. The synthetic application of enzymes is an important part of many research and industrial application, thus the presented topic could be relevant and interesting, however the novelty of the work is totally missing. Substrate 1-phenylethanol and lipases from Candida rugosa and Burcholderia cepaica are well known pairs. The presented results are unclear and contains huge mistakes.
Some serious critical comments:
The aim and novelty of the work is totally unclear.
The illustration of results on diagrams are very weak, and they do not meet the standard of an international scientific publication.
Obvious correlations are presented, thus nothing novel information can be found in this paper.
Two decimals values for ee is inadequate, only one decimal could be accepted due to resolution of analytical technique.
The comparison of different reaction conditions is relevant only at the liner conversion interval, thus conversion around 0.5% and almost 50% is not acceptable.
Calculation of E is also unacceptable, while E larger then 200 is very inaccurate while it comes from a logarithmic equations. Thus, if E is larger than 200, only the >200 can be accepted. Value 378.95 is surely incorrect.
The illustration of results on diagrams are very weak, and they do not meet the standard of an international scientific publication.
Because of the above mentioned critical comment, I do not recommend this paper for publication in journal Catalysts.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
In this study, the resolutions of (R,S)-1-phenylethanol to obtain enantiomerically pure 1-phenylethyl acetate with the use of various catalytic systems containing ionic liquids and n-heptane or toluene as reaction medium were concerned, and Burkholderia cepacia lipase, vinyl acetate and n-heptane with [EMIM][BF4] were selected for the reaction.
Comments:
1. The main experimental results should be given in the abstract.
2. What’s the advantages with the use of ionic liquids in reaction medium for this reaction. It would be better to rewrite the “Introduction” to make it clearly and stronger.
3. More detailed reaction conditions should be provided for the experiments, include molar ratio for each reagent. Page 11, line 279, vinyl acetate (28,25μL), 28,25μL should be 28.25μL? please confirm.
4. In this study, only several ionic liquids, [HMIM][BF4], [OMIM][Cl], [EMIM][BF4] and [DMIM][MeSO4] were investigated, why authors selected these type of ionic liquids for the resolution of (R,S)-1-phenylethanol?
Author Response
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Author Response File: Author Response.pdf
Reviewer 4 Report
In the manuscript titled “The application of two-phase catalytic system in enantioselective separation of racemic compound”, the authors reported a strategy to produce enantiomerically pure 1-phenylethyl acetate by using lipases with the catalytic systems containing ionic liquids and organic solvent. Lipases from different organisms, and different solvents and ionic liquids were examined. The results are helpful in developing new biocatalytic systems for the synthesis of enantiomerically pure acetate by kinetic resolution. I recommend the publication of the present manuscript. However, the current title is too general for this specific study and should be modified. The language needs polishing.
Author Response
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Author Response File: Author Response.pdf
