The aim of this critical review is to provide a broad but digestible overview of mechanochemical synthesis, i.e. reactions conducted by grinding solid reactants together with no or minimal solvent. Although mechanochemistry has historically been a sideline approach to synthesis it may soon move into the mainstream because it is increasingly apparent that it can be practical, and even advantageous, and because of the opportunities it provides for developing more sustainable methods. Concentrating on recent advances, this article covers industrial aspects, inorganic materials, organic synthesis, cocrystallisation, pharmaceutical aspects, metal complexes (including metal–organic frameworks), supramolecular aspects and characterization methods. The historical development, mechanistic aspects, limitations and opportunities are also discussed (314 references).

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Mechanochemistry: opportunities for new and cleaner synthesis

Small-molecule H-bond donors in asymmetric catalysis.

Hydrogen bonding is responsible for the structure of much of the world around us. The unusual and complex properties of bulk water, the ability of proteins to fold into stable three-dimensional structures, the fidelity of DNA base pairing, and the binding of ligands to receptors are among the manifestations of this ubiquitous noncovalent interaction. In addition to its primacy as a structural determinant, hydrogen bonding plays a crucial functional role in catalysis. Hydrogen bonding to an electrophile serves to decrease the electron density of this species, activating it toward nucleophilic attack. This principle is employed frequently by Nature's catalysts, enzymes, for the acceleration of a wide range of chemical processes. Recently, organic chemists have begun to appreciate the tremendous potential offered by hydrogen bonding as a mechanism for electrophile activation in small-molecule, synthetic catalyst systems. In particular, chiral hydrogen-bond donors have emerged as a broadly applicable class of catalysts for enantioselective synthesis. This review documents these advances, emphasizing the structural and mechanistic features that contribute to high enantioselectivity in hydrogen-bond-mediated catalytic processes.

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Asymmetric catalysis by chiral hydrogen-bond donors.

One of the most active current areas of chemical research is centered on how to synthesize handed (chiral) compounds in a selective manner, rather than as mixtures of mirror-image forms (enantiomers) with different three-dimensional structures (stereochemistries). Nature points the way in this endeavor: different enantiomers of a given biomolecule can exhibit dramatically different biological activities, and enzymes have therefore evolved to catalyze reactions with exquisite selectivity for the formation of one enantiomeric form over the other. Drawing inspiration from these natural catalysts, chemists have developed a variety of synthetic small-molecule catalysts that can achieve levels of selectivity approaching, and in some cases matching, those observed in enzymatic reactions.

Privileged Chiral Catalysts

The key attribute of the thiol-Michael addition reaction that makes it a prized tool in materials science is its modular “click” nature, which allows for the implementation of this highly efficient, “green” reaction in applications that vary from small molecule synthesis to in situ polymer modifications in biological systems to the surface functionalization of material coatings. Over the past few decades, interest in the thiol-Michael addition reaction has increased dramatically, as is evidenced by the number of studies that have been dedicated to elucidating different aspects of the reaction that range from an in-depth analysis aimed at understanding the mechanistic pathways of the reaction to synthetic studies that have examined modifying molecular structures with the aim of yielding highly efficient thiol-Michael reaction monomers. This review examines the reaction mechanisms, the substrates and catalysts used in the reaction, and the subsequent implementation of the thiol-Michael reaction in materials...

The Thiol-Michael Addition Click Reaction: A Powerful and Widely Used Tool in Materials Chemistry

Insights into the role played by modified cinchona alkaloids in the Sharpless asymmetric dihydroxylation inspired studies of modified cinchona alkaloids as chiral organic catalysts that lead to the development of highly enantioselective alcoholyses for the desymmetrization, kinetic resolution, and dynamic kinetic resolution of cyclic anhydrides, cyanation of ketones, and 1,4-addition of thiols to cylic enones. These studies demonstrate the potential of modified cinchona alkaloids as broadly useful chiral organic catalysts for asymmetric synthesis.

Asymmetric Organic Catalysis with Modified Cinchona Alkaloids

Asymmetric Alcoholysis of Cyclic Anhydrides

A Highly Enantioselective and General Conjugate Addition of Thiols to Cyclic Enones with an Organic Catalyst This work was financially supported by National Institutes of Health (GM-61591), Research Corporation (RI-0311), and the Harcourt General Charitable Foundation.

bifunctional hemiesters are versatile chiral building blocks for asymmetric synthesis. 1-9 Due to its considerable potential in organic synthesis, the development of enantioselective desymmetrization of prochiral cyclic anhydrides has drawn much attention. 10-15 Despite considerable effort, 12b,13-15 the development of an effective catalytic desymmetrization of prochiral cyclic anhydrides remains a highly desirable yet elusive goal. In this paper we wish to report a significant advance toward achieving this goal. Oda and Aitken reported respectively that cinchona alkaloids catalyze asymmetric methanolysis of various mono-, bi-, and tricyclic anhydrides to afford the corresponding chiral hemiesters in good to excellent yields and in moderate ee (up to 76% ee).13,14,16In searching for a more effective chiral amine catalyst for the desymmetrization of cyclic anhydrides, we were attracted to a number of readily available ethers of cinchona alkaloids that were developed by Sharpless and co-workers in their landmark investigations of the asymmetric dihydroxylation of simple olefins.17 The exceptional effectiveness of these amine ligands in the promotion of osmium-catalyzed asymmetric oxidation reactions is attributed to their capability to form an enzyme-like chiral pocket. 18,19 We hypothesized that the same feature in principle could make these chiral amines effective chiral Lewis base catalysts for asymmetric nucleophile -electrophile reactions. With these considerations in mind and using 2,3-dimethylsuccinic anhydride ( 3) as the model substrate, we screened a variety of commercially available aryl ethers and esters of cinchona alkaloids for their ability to catalyze enantioselective alcoholysis of prochiral cyclic anhydrides. The results of our screening study are presented in Table 1. * To whom correspondence should be addressed. (1) Toyota, M.; Yokota, M.; Ihara, M. Org. Lett.1999, 1, 1627. (2) Couche, E.; Deschatrettes, R.; Poumellec, K.; Bortolussi, M.; Mandvile, G.; Bloch, R.Synlett1999, 87. (3) Paterson, I.; Cowden, C. J.; Woodrow, M. D. Tetrahedron Lett. 1998, 39, 6037. (4) (a) Borzilleri, R. B.; Weinreb, S. M. J. Am. Chem. Soc. 1994, 116, 9789. (b) Borzilleri, R. B.; Weinreb, S. M.; Parvez, M. J. Am. Chem. Soc. 1995, 117, 10905. (5) Marie, F. B. C.; Mackiewicz, P.; Roul, J. M.; Buendia, J. Tetrahedron Lett. 1992, 33, 4889. (6) (a) Ohtani, M.; Matsuura, T.; Watanabe, F.; Narisada, M. J. Org. Chem. 1991, 56, 4120. (b) Ohtani, M.; Matsuura, T.; Watanabe, F.; Narisada, M. J. Org. Chem.1991, 56, 2122. (7) Wender, P. A.; Singh, S. K. Tetrahedron Lett.1990, 31, 2517. (8) Suzuki, T.; Tomino, A.; Matsuda, Y.; Unno, K.; Kametani, T. Heterocycle1980, 14, 1735. (9) (a) Heathcock, C. H.; Hadley, C. R.; Rosen, T.; Theisen, P. D.; Hecker, S. J.J. Med. Chem. 1987, 30, 1858. (b) Hecker, S. J.; Heathcock, C. H. J. Am. Chem. Soc. 1986, 108, 4586. (c) Rosen, T.; Heathcock, C. H. J. Am. Chem. Soc. 1985, 107, 3731. (10) For a recent review see: Willis, M. C. J Chem. Soc., Perkins Tran. 1 1999, 1765. (11) For representative examples of chiral auxiliary-based methods see: (a) Albers, T.; Biagini, S. C. G.; Hibbs, D. E.; Hursthouse, M. B.; Malik, K. M. A.; North, M.; Uriarte, E.; Zagotto, G. Synthesis1996, 393. (b) Konoike, T.; Araki, Y. J. Org. Chem.1994, 59, 7849. (c) Shimizu, M.; Matsukawa, K.; Fujisawa, T.Bull. Chem. Soc. Jpn. 1993, 66, 2128. (d) Theisen, P. D.; Heathcock, C. H.J. Org. Chem.1993, 58, 142. (12) For the most successful examples of chiral mediator-based methods see: (a) Seebach, D.; Jaeschke, G.; Wang, Y. M. Angew. Chem., Int. Ed. Engl. 1995, 34, 2395. (b) Jaeschke, G.; Seebach, D. J. Org. Chem.1998, 63, 1190. (c) Bolm, C.; Gerlach, A.; Dinter, C. L. Synlett1999, 195. (13) (a) Hiratake, J.; Yamamoto, Y.; Oada, J. J. Chem. Soc., Chem. Commun.1985, 1717. (b) Hiratake, J.; Inagaki, M.; Yamamoto, Y.; Oada, J. J. Chem. Soc., Perkin. Trans. 1 1987, 1053. (14) (a) Aitken, R. A.; Gopal, J.; Hirst, J. A. J Chem. Soc., Chem. Commun. 1988, 632. (b) Aitken, R. A.; Gopal, J. Tetrahedron: Asymmetry 1990, 1, 517. (15) For enzyme-catalyzed alcoholysis of cyclic anhydrides see: (a) Ozegowski, R.; Kunath, A.; Schick, H. Tetrahedron: Asymmetry 1995, 6, 1191. (b) Yamamoto, K.; Nishioka, T.; Oada, J. Tetrahedron Lett. 1988, 29, 1717. (c) Yamamoto, Y.; Yamamoto, K.; Nishioka, T.; Oada, J. Agric. Biol. Chem.1988, 52, 3087. (16) For a Lewis base-catalyzed highly enantioselective acylation of meso diols see: Ruble, J. C.; Tweddell, J.; Fu, G. C. J. Org. Chem. 1998, 63, 2794. (17) For leading references see: (a) Sharpless, K. B.; Amberg, W.; Bennani, Y. L.; Crispino, G. A.; Hartung, J.; Jeong, K.-S.; Kwong, H.-L.; Morikawa, K.; Wang, Z.-M.; Xu, D.; Zhang, X.-L.J. Org. Chem.1991, 56, 4585. (b) Sharpless, K. B.; Amberg, W.; Bennani, Y. L.; Crispino, G. A.; Hartung, J.; Jeong, K.-S.; Kwong, H.-L.; Morikawa, K.; Wang, Z.-M.; Xu, D.; Zhang, X.-L. J. Org. Chem.1992, 57, 2768. (c) Crispino, G. A.; Jeong, K.-S.; Kolb, H. C.; Wang, Z.-M.; Xu, D.; Sharpless, K. B. J Org. Chem.1993, 58, 3785. (d) Kolb, H. C.; VanNieuwenhze, M. S.; Sharpless, K. B. Chem. Re V. 1994, 94, 2483. (e) Becker, H.; Sharpless, K. B. Angew. Chem., Int. Ed. Engl. 1996, 35, 451. (f) Marko, I. E.; Svendsen, J. S. Dihydroxylation of Carbon -Carbon Double Bonds. InComprehensi Ve Asymmetric Catalysis ; Jacobsen, E. N., Pfaltz, A., Yamamoto, H., Eds; Springer: Heidelberg, 1999; Chapter 20. (18) (a) Dijkstra, G. D. H.; Kellogg, R. M.; Wynberg, H.; Svendsen, J. S.; Marko, I.; Sharpless, K. B. J. Am. Chem. Soc. 1989, 111, 8069. (b) Kolb, H. C.; Andersson, P. G.; Sharpless, K. B. J. Am. Chem. Soc. 1994, 116, 1278. (19) (a) Corey, E. J.; Noe, M. C. J. Am. Chem. Soc. 1993, 115, 12579. (b) Corey, E. J.; Noe, M. C.; Sarshar, S. Tetrahedron Lett.1994, 35, 2861. (c) Corey, E. J.; Noe, M. C. J. Am. Chem. Soc. 1996, 118, 319. (d) Corey, E. J.; Noe, M. C.J. Am. Chem. Soc. 1996, 118, 11038. Table 1. Desymmetrization of 2,3-Dimethylsuccinic Anhydride ( 3)

https://people.brandeis.edu/%7Edeng/publication/deng4.pdf

Yonggang Chen

Papers

Asymmetric Organic Catalysis with Modified Cinchona Alkaloids

Asymmetric Alcoholysis of Cyclic Anhydrides

A Highly Enantioselective and General Conjugate Addition of Thiols to Cyclic Enones with an Organic Catalyst This work was financially supported by National Institutes of Health (GM-61591), Research Corporation (RI-0311), and the Harcourt General Charitable Foundation.

A Highly Enantioselective Catalytic Desymmetrization of Cyclic Anhydrides with Modified Cinchona Alkaloids

A highly enantioselective and general conjugate addition of thiols to cyclic enones with an organic catalyst.