Pub Date : 2019-03-04DOI: 10.1039/9781788016490-00066
J. M. Saa, Victor J. Lillo, J. Mansilla
The main paradigm of today's chemistry is sustainability. In pursuing sustainability, we need to learn from chemical processes carried out by Nature and realize that Nature does not use either strong acids, or strong bases or fancy reagents to achieve outstanding chemical processes. Instead, enzyme activity leans on the cooperation of several chemical entities to avoid strong acids or bases or to achieve such an apparently simple goal as transferring a proton from an NuH unit to an E unit (NuH + E → Nu–EH). Hydrogen bond catalysis emerged strongly two decades ago in trying to imitate Nature and avoid metal catalysis. Now to mount another step in pursuing the goal of sustainability, the focus is upon cooperativity between the different players involved in catalysis. This chapter looks at the concept of cooperativity and, more specifically, (a) examines the role of cooperative hydrogen bonded arrays of the general type NuH⋯(NuH)n⋯NuH (i.e. intermolecular cooperativity) to facilitate general acid–base catalysis, not only in the solution phase but also under solvent-free and catalyst-free conditions, and, most important, (b) analyzes the capacity of designer chiral organocatalysts displaying intramolecular networks of cooperative hydrogen bonds (NCHBs) to facilitate enantioselective synthesis by bringing conformational rigidity to the catalyst in addition to simultaneously increasing the acidity of key hydrogen atoms so to achieve better complementarity in the highly polarized transition states.
{"title":"CHAPTER 3. Catalysis by Networks of Cooperative Hydrogen Bonds","authors":"J. M. Saa, Victor J. Lillo, J. Mansilla","doi":"10.1039/9781788016490-00066","DOIUrl":"https://doi.org/10.1039/9781788016490-00066","url":null,"abstract":"The main paradigm of today's chemistry is sustainability. In pursuing sustainability, we need to learn from chemical processes carried out by Nature and realize that Nature does not use either strong acids, or strong bases or fancy reagents to achieve outstanding chemical processes. Instead, enzyme activity leans on the cooperation of several chemical entities to avoid strong acids or bases or to achieve such an apparently simple goal as transferring a proton from an NuH unit to an E unit (NuH + E → Nu–EH). Hydrogen bond catalysis emerged strongly two decades ago in trying to imitate Nature and avoid metal catalysis. Now to mount another step in pursuing the goal of sustainability, the focus is upon cooperativity between the different players involved in catalysis. This chapter looks at the concept of cooperativity and, more specifically, (a) examines the role of cooperative hydrogen bonded arrays of the general type NuH⋯(NuH)n⋯NuH (i.e. intermolecular cooperativity) to facilitate general acid–base catalysis, not only in the solution phase but also under solvent-free and catalyst-free conditions, and, most important, (b) analyzes the capacity of designer chiral organocatalysts displaying intramolecular networks of cooperative hydrogen bonds (NCHBs) to facilitate enantioselective synthesis by bringing conformational rigidity to the catalyst in addition to simultaneously increasing the acidity of key hydrogen atoms so to achieve better complementarity in the highly polarized transition states.","PeriodicalId":10054,"journal":{"name":"Catalysis Series","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88364888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-03-04DOI: 10.1039/9781788016490-00137
S. Yamada
The cation–π interaction is an attractive noncovalent interaction between a cation and a π-face. Owing to the stronger interaction energy than those of the other π interactions, such as π–π and CH–π interactions, the cation–π interaction has recently been recognized as a new tool for controlling the regio- and stereoselectivities in various types of organic reactions. This chapter attempts to cover a variety of organic reactions assisted by interactions between unreactive onium ions and π-faces, which will provide comprehensive knowledge on the role of cation–π interactions in organic synthesis.
{"title":"CHAPTER 6. Onium Ion-assisted Organic Reactions Through Cation–π Interactions","authors":"S. Yamada","doi":"10.1039/9781788016490-00137","DOIUrl":"https://doi.org/10.1039/9781788016490-00137","url":null,"abstract":"The cation–π interaction is an attractive noncovalent interaction between a cation and a π-face. Owing to the stronger interaction energy than those of the other π interactions, such as π–π and CH–π interactions, the cation–π interaction has recently been recognized as a new tool for controlling the regio- and stereoselectivities in various types of organic reactions. This chapter attempts to cover a variety of organic reactions assisted by interactions between unreactive onium ions and π-faces, which will provide comprehensive knowledge on the role of cation–π interactions in organic synthesis.","PeriodicalId":10054,"journal":{"name":"Catalysis Series","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73456876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-03-04DOI: 10.1039/9781788016490-00628
R. Á. Boto, T. Woller, J. Contreras‐García, Israel Fernández
This chapter illustrates the good performance of the recently introduced noncovalent interactions (NCI) method in understanding molecular reactivity. This method is not only helpful in identifying the nature of the NCIs but can be also used to gain a deeper insight into the influence of such interactions on the outcome of different fundamental transformations in chemistry, including catalysed processes. To this end, representative catalysed transformations were selected where the NCI method was key to rationalizing different aspects such as reactivity trends and selectivity. The catalysed reactions chosen range from relatively simple transformations such as Diels–Alder cycloadditions to more intricate transition metal- and organo-catalysed processes.
{"title":"CHAPTER 29. Analysis of Reactivity from the Noncovalent Interactions Perspective","authors":"R. Á. Boto, T. Woller, J. Contreras‐García, Israel Fernández","doi":"10.1039/9781788016490-00628","DOIUrl":"https://doi.org/10.1039/9781788016490-00628","url":null,"abstract":"This chapter illustrates the good performance of the recently introduced noncovalent interactions (NCI) method in understanding molecular reactivity. This method is not only helpful in identifying the nature of the NCIs but can be also used to gain a deeper insight into the influence of such interactions on the outcome of different fundamental transformations in chemistry, including catalysed processes. To this end, representative catalysed transformations were selected where the NCI method was key to rationalizing different aspects such as reactivity trends and selectivity. The catalysed reactions chosen range from relatively simple transformations such as Diels–Alder cycloadditions to more intricate transition metal- and organo-catalysed processes.","PeriodicalId":10054,"journal":{"name":"Catalysis Series","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90975082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-03-04DOI: 10.1039/9781788016490-00440
Víctor L. Rechac, Encarnación Peris Sanchis, F. X. L. I. Xamena
Metal–organic frameworks (MOFs) have attracted enormous interest in recent years owing to their potential use as heterogeneous catalysts. MOF catalysts can be designed with active sites at the metallic units or at the organic ligands or trapped inside their regular pore system. This chapter illustrates how cavity effects (i.e. the chemical environment in which the active sites are located) can have a large influence on their final catalytic properties through specific host–guest interactions, thereby introducing additional tools to modulate chemical specificity.
{"title":"CHAPTER 20. Cavity Effects in Metal–Organic Frameworks","authors":"Víctor L. Rechac, Encarnación Peris Sanchis, F. X. L. I. Xamena","doi":"10.1039/9781788016490-00440","DOIUrl":"https://doi.org/10.1039/9781788016490-00440","url":null,"abstract":"Metal–organic frameworks (MOFs) have attracted enormous interest in recent years owing to their potential use as heterogeneous catalysts. MOF catalysts can be designed with active sites at the metallic units or at the organic ligands or trapped inside their regular pore system. This chapter illustrates how cavity effects (i.e. the chemical environment in which the active sites are located) can have a large influence on their final catalytic properties through specific host–guest interactions, thereby introducing additional tools to modulate chemical specificity.","PeriodicalId":10054,"journal":{"name":"Catalysis Series","volume":"133 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81737699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-03-04DOI: 10.1039/9781788016490-00377
B. A. Neto, Haline G. O. Alvim, A. Lapis
In this book chapter the effects produced in using ionic liquids over multicomponent reactions are presented and discussed. Ionic liquids may be used as reaction media (solvents) or as catalysts for several multicomponent reactions. It is observed that many multicomponent reactions characteristically proceed through charged intermediates, thereby rendering them as desirable features to interact with cations and/or anions of ionic liquids. These interactions are mostly ruled by Coulombic attraction/stabilisation between the charged intermediates and the ionic liquid ions. These Coulombic interactions give rise to new ion pairs and larger supramolecular aggregates (higher ion clusters). Additional interactions such as hydrogen bonds and van der Waals forces also play a role in the formation, directionality (entropic drivers) and stabilisation of these ion pairs (and larger supramolecular clusters) between the charged intermediates and the ionic liquid ions; an effect typically noted for imidazolium derivatives. Understanding the multicomponent reaction mechanism in this context is essential in aiming at predicting a positive ionic liquid effect. Many multicomponent reactions have proven to be capable of undergoing two or more competitive reaction mechanisms, but usually the final multicomponent reaction adduct is the same regardless of the reaction pathway. Ionic liquids may also contribute to tune the reaction through one specific mechanism. As we intend to show herein, the combination of multicomponent reactions and ionic liquids typically returns excellent results and produces many achievements, although both are a huge challenge to understand and to predict their effects over multicomponent reactions.
{"title":"CHAPTER 17. Ionic Liquid Effect in Catalysed Multicomponent Reactions","authors":"B. A. Neto, Haline G. O. Alvim, A. Lapis","doi":"10.1039/9781788016490-00377","DOIUrl":"https://doi.org/10.1039/9781788016490-00377","url":null,"abstract":"In this book chapter the effects produced in using ionic liquids over multicomponent reactions are presented and discussed. Ionic liquids may be used as reaction media (solvents) or as catalysts for several multicomponent reactions. It is observed that many multicomponent reactions characteristically proceed through charged intermediates, thereby rendering them as desirable features to interact with cations and/or anions of ionic liquids. These interactions are mostly ruled by Coulombic attraction/stabilisation between the charged intermediates and the ionic liquid ions. These Coulombic interactions give rise to new ion pairs and larger supramolecular aggregates (higher ion clusters). Additional interactions such as hydrogen bonds and van der Waals forces also play a role in the formation, directionality (entropic drivers) and stabilisation of these ion pairs (and larger supramolecular clusters) between the charged intermediates and the ionic liquid ions; an effect typically noted for imidazolium derivatives. Understanding the multicomponent reaction mechanism in this context is essential in aiming at predicting a positive ionic liquid effect. Many multicomponent reactions have proven to be capable of undergoing two or more competitive reaction mechanisms, but usually the final multicomponent reaction adduct is the same regardless of the reaction pathway. Ionic liquids may also contribute to tune the reaction through one specific mechanism. As we intend to show herein, the combination of multicomponent reactions and ionic liquids typically returns excellent results and produces many achievements, although both are a huge challenge to understand and to predict their effects over multicomponent reactions.","PeriodicalId":10054,"journal":{"name":"Catalysis Series","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82627562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-03-04DOI: 10.1039/9781788016490-00283
Nuno M. R. Martins, L. Martins
The relative complexity of noncovalent interactions has made them challenging to study. Nevertheless, theory and modelling have now reached the stage that allows their physical origins to be explained and reliable insight to be gained into their effects on chemical transformations. This chapter discusses the influence of coordination and noncovalent interactions in Baeyer–Villiger oxidations. These attractive forces can be powerful tools in the formation/stabilization of intermediates and in controlling the product outcome of a reaction.
{"title":"CHAPTER 13. Baeyer–Villiger Oxidation Promoted by Noncovalent Interactions","authors":"Nuno M. R. Martins, L. Martins","doi":"10.1039/9781788016490-00283","DOIUrl":"https://doi.org/10.1039/9781788016490-00283","url":null,"abstract":"The relative complexity of noncovalent interactions has made them challenging to study. Nevertheless, theory and modelling have now reached the stage that allows their physical origins to be explained and reliable insight to be gained into their effects on chemical transformations. This chapter discusses the influence of coordination and noncovalent interactions in Baeyer–Villiger oxidations. These attractive forces can be powerful tools in the formation/stabilization of intermediates and in controlling the product outcome of a reaction.","PeriodicalId":10054,"journal":{"name":"Catalysis Series","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77540907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-03-04DOI: 10.1039/9781788016490-00608
G. Velmurugan, R. V. Solomon, Dhurairajan Senthilnathan, P. Venuvanalingam
Noncovalent interactions (NCIs) are Nature's choice for maintaining biological structure and carrying out many biological functions. These delicate forces become stronger and more specific when acting together. They were detected very early as short contacts in crystals or in gas-phase complexes but their systematic understanding is recent. Theoretical methods have greatly aided in understanding their nature and variety and this eventually led to their use in developing chemical, material, biological and technological applications. Recent developments in computer hardware and software have enabled scientists to probe the movements at the atomic level in the active site of complex biological systems and understand the biological processes. This chapter is devoted to explaining the role of NCIs in biocatalysis from a computational perspective. It first introduces the popular theoretical methods used to characterize NCIs and then explains the role of the three main NCIs, namely hydrogen bonding, halogen bonding and hydrophobic interactions, in biocatalysis through six case studies from the literature. The chapter ends with a summary and future directions of this topic.
{"title":"CHAPTER 28. Noncovalent Interactions in Biocatalysis – A Theoretical Perspective","authors":"G. Velmurugan, R. V. Solomon, Dhurairajan Senthilnathan, P. Venuvanalingam","doi":"10.1039/9781788016490-00608","DOIUrl":"https://doi.org/10.1039/9781788016490-00608","url":null,"abstract":"Noncovalent interactions (NCIs) are Nature's choice for maintaining biological structure and carrying out many biological functions. These delicate forces become stronger and more specific when acting together. They were detected very early as short contacts in crystals or in gas-phase complexes but their systematic understanding is recent. Theoretical methods have greatly aided in understanding their nature and variety and this eventually led to their use in developing chemical, material, biological and technological applications. Recent developments in computer hardware and software have enabled scientists to probe the movements at the atomic level in the active site of complex biological systems and understand the biological processes. This chapter is devoted to explaining the role of NCIs in biocatalysis from a computational perspective. It first introduces the popular theoretical methods used to characterize NCIs and then explains the role of the three main NCIs, namely hydrogen bonding, halogen bonding and hydrophobic interactions, in biocatalysis through six case studies from the literature. The chapter ends with a summary and future directions of this topic.","PeriodicalId":10054,"journal":{"name":"Catalysis Series","volume":"99 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82240107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-03-04DOI: 10.1039/9781788016490-00503
Y. Zhai, S. Wang, S. Chuang
CO2 capture from fossil fuel (coal and natural gas) power plants has been considered a key strategy in mitigating global climate changes. One promising approach under development is the use of solid amine sorbents to bind CO2 in the form of ammonium carbamate from the flue gas of coal-fired power plants in a CO2 capture process. The CO2 capture process by solid amines consists of a number of steps: CO2 adsorption, diffusion and desorption. These steps are governed by the nature of the hydrogen bonding between the ammonium cation and the carbamate anion. This chapter discusses the sources of greenhouse gas emissions, basic principles governing the trapping of infrared energy by greenhouse gases, especially CO2, and the mechanistic step involved in the thermal swing CO2 capture process by solid amines. Infrared spectroscopy is used to illustrate the nature of hydrogen bonding in adsorbed CO2 (i.e. ammonium carbamate) and co-adsorbed CO2/H2O (i.e. hydronium carbamate). In situ infrared spectroscopy shows that hydrogen bonding interactions among these adsorbed species shift the stretching band of N–H and O–H to lower wavenumbers. The extent of hydrogen bonding is reflected in the degree of shift and broadness of the N–H and O–H stretching bands. Fine tuning solid amine (immobilized amine) sorbents for CO2 capture processes requires controlling the structure of amine sites to facilitate CO2 adsorption, diffusion and desorption.
{"title":"CHAPTER 23. The Nature of Hydrogen Bonding in Adsorbed CO2 and H2O on Solid Amines in CO2 Capture","authors":"Y. Zhai, S. Wang, S. Chuang","doi":"10.1039/9781788016490-00503","DOIUrl":"https://doi.org/10.1039/9781788016490-00503","url":null,"abstract":"CO2 capture from fossil fuel (coal and natural gas) power plants has been considered a key strategy in mitigating global climate changes. One promising approach under development is the use of solid amine sorbents to bind CO2 in the form of ammonium carbamate from the flue gas of coal-fired power plants in a CO2 capture process. The CO2 capture process by solid amines consists of a number of steps: CO2 adsorption, diffusion and desorption. These steps are governed by the nature of the hydrogen bonding between the ammonium cation and the carbamate anion. This chapter discusses the sources of greenhouse gas emissions, basic principles governing the trapping of infrared energy by greenhouse gases, especially CO2, and the mechanistic step involved in the thermal swing CO2 capture process by solid amines. Infrared spectroscopy is used to illustrate the nature of hydrogen bonding in adsorbed CO2 (i.e. ammonium carbamate) and co-adsorbed CO2/H2O (i.e. hydronium carbamate). In situ infrared spectroscopy shows that hydrogen bonding interactions among these adsorbed species shift the stretching band of N–H and O–H to lower wavenumbers. The extent of hydrogen bonding is reflected in the degree of shift and broadness of the N–H and O–H stretching bands. Fine tuning solid amine (immobilized amine) sorbents for CO2 capture processes requires controlling the structure of amine sites to facilitate CO2 adsorption, diffusion and desorption.","PeriodicalId":10054,"journal":{"name":"Catalysis Series","volume":"20 5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89516848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-03-04DOI: 10.1039/9781788016490-00564
D. Zuccaccia, P. Belanzoni, L. Belpassi, G. Ciancaleoni, A. D. Zotto
In this chapter, the role of ion pairing in the mechanism of the reactions promoted by gold(i) catalysts L–Au–X is elucidated by means of both experimental findings and theoretical calculations. The synergy of the approach allowed the full elucidation of the role of the counterion X−. The catalytic performance in the alkoxylation and hydration of alkynes promoted by gold(i) is influenced by the coordinating ability and basicity (proton affinity) of the counterion, the anion/cation relative orientation and the appropriate matching of X− and L. Finally, how the nature of the anion plays a fundamental role in solvent-, silver- and acid-free gold(i)-catalysed hydration of alkynes is highlighted.
{"title":"CHAPTER 26. Role of Ion Pairing in the Mechanisms of Au(i)-catalysed Reactions: Theory and Experiment","authors":"D. Zuccaccia, P. Belanzoni, L. Belpassi, G. Ciancaleoni, A. D. Zotto","doi":"10.1039/9781788016490-00564","DOIUrl":"https://doi.org/10.1039/9781788016490-00564","url":null,"abstract":"In this chapter, the role of ion pairing in the mechanism of the reactions promoted by gold(i) catalysts L–Au–X is elucidated by means of both experimental findings and theoretical calculations. The synergy of the approach allowed the full elucidation of the role of the counterion X−. The catalytic performance in the alkoxylation and hydration of alkynes promoted by gold(i) is influenced by the coordinating ability and basicity (proton affinity) of the counterion, the anion/cation relative orientation and the appropriate matching of X− and L. Finally, how the nature of the anion plays a fundamental role in solvent-, silver- and acid-free gold(i)-catalysed hydration of alkynes is highlighted.","PeriodicalId":10054,"journal":{"name":"Catalysis Series","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79353270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-03-04DOI: 10.1039/9781788016490-00548
M. N. Kopylovich, A. Ribeiro, E. C. Alegria
Chemical transformations induced by mechanical force in solids are remarkable since they facilitate syntheses that are normally difficult to achieve in solution and thus allow the preparation of new molecules and materials or drastic improvements of the yields and selectivities. In many cases, the noncovalent interactions (NCIs) with mechanochemical treatment differ significantly from those which occur in analogous solvent-assisted processes. Moreover, if a “mechanocatalyst” is introduced into the system, it can additionally alter the NCIs, bond energies and properties of the reaction intermediates. As result, the outcome of many mechanocatalytic reactions can be very different in terms of efficiency or even reaction pathways compared with the traditional solution-based procedures or noncatalytic mechanochemical processes. Accordingly, in this chapter, certain mechanocatalytic reactions in which the NCIs play a key role are overviewed and discussed. Additionally, an overview of some experimental techniques used to study mechanochemical activation and the respective NCIs is also provided.
{"title":"CHAPTER 25. Mechanochemical Activation and Catalysis","authors":"M. N. Kopylovich, A. Ribeiro, E. C. Alegria","doi":"10.1039/9781788016490-00548","DOIUrl":"https://doi.org/10.1039/9781788016490-00548","url":null,"abstract":"Chemical transformations induced by mechanical force in solids are remarkable since they facilitate syntheses that are normally difficult to achieve in solution and thus allow the preparation of new molecules and materials or drastic improvements of the yields and selectivities. In many cases, the noncovalent interactions (NCIs) with mechanochemical treatment differ significantly from those which occur in analogous solvent-assisted processes. Moreover, if a “mechanocatalyst” is introduced into the system, it can additionally alter the NCIs, bond energies and properties of the reaction intermediates. As result, the outcome of many mechanocatalytic reactions can be very different in terms of efficiency or even reaction pathways compared with the traditional solution-based procedures or noncatalytic mechanochemical processes. Accordingly, in this chapter, certain mechanocatalytic reactions in which the NCIs play a key role are overviewed and discussed. Additionally, an overview of some experimental techniques used to study mechanochemical activation and the respective NCIs is also provided.","PeriodicalId":10054,"journal":{"name":"Catalysis Series","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76606369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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