A practical and scalable mechanochemical 1,3-dipolar cycloaddition between hydroxyimidoyl chlorides and terminal alkynes catalyzed by Cu/Al2O3 allows a quick access to 3,5-isoxazole derivatives.

opened discussion of the introductory lecture by Elena Boldyreva: I have read quite a few of the articles out of the Institute of Solid State Chemistry and Mechanochemistry. The biggest challenge I have faced is in translating the mill choice to one I can implement in my laboratory. I do not doubt that you are using commercially available mills, they are just not available in the United States. For instance the AGO-2 mill is described as a planetary mill, but only one image exists when searching the internet. Can you recommend a paper that summarizes the mill technologies used at the institute? Elena Boldyreva replied: A review on mechanochemistry in Siberia was recently published by a former director of this institute, who is no longer related to it, but is affiliated with Novosibirsk State University. 1 AGO is described in detail in the book by Avvakumov (one of the co-designers of this high-energy planetary mill), 2 and in the recent revised edition of this book from 2022. 3

A mechanochemical desymmetrization of symmetrical bis‐ and tris‐alkynes by a controlled 1,3‐dipolar cycloaddition reaction using nitrile oxide dipoles (NOs). This operationally simple protocol allows access to 3,5‐isoxazole‐alkyne adducts from easily prepared or commercially available symmetrical bis‐ and tris‐alkynes in moderate to excellent yields. In addition, we have highlighted the synthetic utility of 3,5‐isoxazole‐alkyne by developing a route to access, for the first time, β‐ketoenamine‐alkyne derivatives, and unsymmetrical bis‐3,5‐isoxazoles.

A mechanochemical desymmetrization of symmetrical bis- and tris-alkynes via a controlled 1,3-dipolar cycloaddition reaction with nitrile oxide dipoles has been developed. This convenient, efficient, and simple protocol allows access to 3,5-isoxazole-alkyne adducts from easily prepared or commercially available symmetrical bis- and tris-alkynes in moderate to excellent yield. The synthetic utility of 3,5-isoxazole-alkyne was demonstrated by developing a route to access β-ketoenamine-alkyne derivatives and the synthesis of unsymmetrical bis-3,5-isoxazoles products in good to excellent yields.