Recent Access to Polycycles via Post-Ugi Reactions

Round 1

Reviewer 1 Report

The manuscript "Recent Access to Polycycles via Post-Ugi Reactions" by Xiao Tang and Liangliang Song represents a useful overview of literature after 2019, interesting particularly for Ugi-practitioners

I have a few comments:

A range of yields should be given (e.g., yields 65 – 80%) and not “yields up to xx%”.

Please include the number of building blocks used for each particular reaction.

On several instances, a brief description of R types would be beneficial, particularly when the chemistry is compatible with only limited structural type of Rs

The number of compounds prepared should be included.

The yield and structure of prepared compounds need to be cleared. Scheme 4 indicates a yield of up to 82%. However, concrete examples do not show the compound's 82% yield. What is the logic behind the selection of products

Intermediates shown after the product and labeled "via" should be included in the reaction scheme (between starting chemicals and product)

Minor comments:

Scheme 7: methyl group in structures should be shown "-", not "-Me", analogous to other structures (e.g., scheme 23)

Scheme 13: define X

Author Response

We thank the reviewer for these nice suggestions.

We have given a range of yields, included the number of building blocks, provided a brief description of R types, and shown the number of compounds in the revised manuscript. We have also made the yield and structure of prepared compounds clear, and put intermediates between starting chemicals and products.

We have corrected methyl group in Scheme 7 and defined X in Scheme 13 in the revised manuscript.

Reviewer 2 Report

The review article is well prepared; only those references found after 2019 should be included. It is recommended that this article be accepted for publication after the mentioned minor addition.

1.        Du, X.; Yu, J.; Gong, J.; Zaman, M.; Pereshivko, O.P.; Peshkov, V.A. Gold-Catalyzed Post-Ugi Cascade Transformation for the Synthesis of 2-Pyridones. European J. Org. Chem. 2019, 2019, 2502–2507, doi:10.1002/ejoc.201900027.

2.        Jivani, A.; Kapadiya, K.; Jainik, A.; Khunt, R. Efficacy of Binary Media and Gold Catalyst for the Synthesis of a Conjugates with Cyclohexyl- Tetrazole-Alkyloxyphenyl-Benzenamine through Ugi 4-CC Reactions : Cytotoxic and Single-Crystal Studies Efficacy of Binary Media and Gold Catalyst for the Synthes. Polycycl. Aromat. Compd. 2023, 0, 1–15, doi:10.1080/10406638.2023.2174992.

Also, include a list of abbreviations.

1.      What is the main question addressed by the research?

This manuscript is a review by Xiao Tang et al., where they recount articles published after 2019 about Ugi-reactions for obtaining polycycles.

2. Do you consider the topic original or relevant in the field? Does it
address a specific gap in the field?

3. What does it add to the subject area compared with other published
material?

This contribution offers an update of articles published after 2019. The other review articles mentioned by the authors in the manuscript only cover from 2019 backward.

4. What specific improvements should the authors consider regarding the
methodology? What further controls should be considered?

5. Are the conclusions consistent with the evidence and arguments presented
and do they address the main question posed?

Yes, it is.

6. Are the references appropriate?

7. Please include any additional comments on the tables and figures.

Please include the number of chemical reactants and the products within the reactions and detail this in the text so that it is easier for the reader to know which chemical species you are referring to.

Author Response

We appreciate the interest of the reviewer in our manuscript.

We have added a list of abbreviations in the revised manuscript. And the suggested two references are outside the scope of this review, so we did not add them in the revised manuscript. Because this review is focused on post-Ugi reactions for the synthesis of polycycles, not simple 2-pyridones and tetrazoles.

We used Google and Scifinder to find the published articles.

We have shown the number of compounds in the revised manuscript.