1
|
Silva IDA, Bartalucci E, Bolm C, Wiegand T. Opportunities and Challenges in Applying Solid-State NMR Spectroscopy in Organic Mechanochemistry. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2304092. [PMID: 37407000 DOI: 10.1002/adma.202304092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/12/2023] [Accepted: 06/28/2023] [Indexed: 07/07/2023]
Abstract
In recent years it is shown that mechanochemical strategies can be beneficial in directed conversions of organic compounds. Finding new reactions proved difficult, and due to the lack of mechanistic understanding of mechanochemical reaction events, respective efforts have mostly remained empirical. Spectroscopic techniques are crucial in shedding light on these questions. In this overview, the opportunities and challenges of solid-state nuclear magnetic resonance (NMR) spectroscopy in the field of organic mechanochemistry are discussed. After a brief discussion of the basics of high-resolution solid-state NMR under magic-angle spinning (MAS) conditions, seven opportunities for solid-state NMR in the field of organic mechanochemistry are presented, ranging from ex situ approaches to structurally elucidated reaction products obtained by milling to the potential and limitations of in situ solid-state NMR approaches. Particular strengths of solid-state NMR, for instance in differentiating polymorphs, in NMR-crystallographic structure-determination protocols, or in detecting weak noncovalent interactions in molecular-recognition events employing proton-detected solid-state NMR experiments at fast MAS frequencies, are discussed.
Collapse
Affiliation(s)
| | - Ettore Bartalucci
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470, Mülheim/Ruhr, Germany
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074, Aachen, Germany
| | - Carsten Bolm
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074, Aachen, Germany
| | - Thomas Wiegand
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470, Mülheim/Ruhr, Germany
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074, Aachen, Germany
| |
Collapse
|
2
|
Margetić D. Recent applications of mechanochemistry in synthetic organic chemistry. PURE APPL CHEM 2023. [DOI: 10.1515/pac-2022-1202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Abstract
The promotion of chemical reactions by an unconventional energy source, mechanical energy (mechanochemistry) has increasing number of applications in organic synthesis. The advantages of mechanochemistry are versatile, from reduction of solvent use, increase of reaction efficiency to better environmental sustainability. This paper gives a short review on the recent developments in the fast growing field of organic mechanochemistry which are illustrated by selected examples.
Collapse
Affiliation(s)
- Davor Margetić
- Laboratory for Physical Organic Chemistry, Division of Organic Chemistry and Biochemistry , Ruđer Bošković Institute , Bijenička c. 54 , 10000 Zagreb , Croatia
| |
Collapse
|
3
|
Gonnet L, Borchers TH, Lennox CB, Vainauskas J, Teoh Y, Titi HM, Barrett CJ, Koenig SG, Nagapudi K, Friščić T. The " η-sweet-spot" ( ηmax) in liquid-assisted mechanochemistry: polymorph control and the role of a liquid additive as either a catalyst or an inhibitor in resonant acoustic mixing (RAM). Faraday Discuss 2023; 241:128-149. [PMID: 36239309 DOI: 10.1039/d2fd00131d] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Resonant acoustic mixing (RAM) offers a simple, efficient route for mechanochemical synthesis in the absence of milling media or bulk solvents. Here, we show the use of RAM to conduct the copper-catalysed coupling of sulfonamides and carbodiimides. This coupling was previously reported to take place only by mechanochemical ball milling, while in conventional solution environments it is not efficient, or does not take place at all. The results demonstrate RAM as a suitable methodology to conduct reactions previously accessed only by ball milling and provide a detailed, systematic overview of how the amount of liquid additive, measured by the ratio of liquid volume to weight of reactants (η, in μL mg-1), can affect the course of a mechanochemical reaction and the polymorphic composition of its product. Switching from ball milling to RAM allowed for the discovery of a new polymorph of the model sulfonylguanidine obtained by catalytic coupling of di(cyclohexyl)carbodiimide (DCC) and p-toluenesulfonamide, and the ability to control reaction temperature in RAM enabled in situ control of the polymorphic behaviour of this nascent product. We show that the reaction conversion for a given reaction time does not change monotonically but, instead, achieves a maximum for a well-defined η-value. This "η-sweet-spot" of conversion is herein designated ηmax. The herein explored reactions demonstrate sensitivity to η on the order of 0.01 μL mg-1, which corresponds to an amount of liquid additive below 5 mol% compared to the reactants, and is at least one to two orders of magnitude lower than the η-value typically considered in the design of liquid-assisted ball milling mechanochemical reactions. Such sensitivity suggests that strategies to optimise liquid-assisted mechanochemical reactions should systematically evaluate η-values at increments of 0.01 μL mg-1, or even finer. At η-values other than ηmax the reaction conversion drops off, demonstrating that the same liquid additive can act either as a catalyst or an inhibitor of a mechanochemical reaction, depending on the amount.
Collapse
Affiliation(s)
- Lori Gonnet
- Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montreal, QC, H3H 0B8, Canada.
| | - Tristan H Borchers
- Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montreal, QC, H3H 0B8, Canada.
| | - Cameron B Lennox
- Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montreal, QC, H3H 0B8, Canada.
| | - Jogirdas Vainauskas
- Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montreal, QC, H3H 0B8, Canada.
| | - Yong Teoh
- Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montreal, QC, H3H 0B8, Canada.
| | - Hatem M Titi
- Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montreal, QC, H3H 0B8, Canada.
| | - Christopher J Barrett
- Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montreal, QC, H3H 0B8, Canada.
| | - Stefan G Koenig
- Small Molecule Pharmaceutical Sciences, Genentech Inc., One DNA Way, South San Francisco, CA 94080, USA.
| | - Karthik Nagapudi
- Small Molecule Pharmaceutical Sciences, Genentech Inc., One DNA Way, South San Francisco, CA 94080, USA.
| | - Tomislav Friščić
- Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montreal, QC, H3H 0B8, Canada. .,School of Chemistry, University of Birmingham, Edgbaston, B15 2TT, UK.
| |
Collapse
|
4
|
Cuccu F, De Luca L, Delogu F, Colacino E, Solin N, Mocci R, Porcheddu A. Mechanochemistry: New Tools to Navigate the Uncharted Territory of "Impossible" Reactions. CHEMSUSCHEM 2022; 15:e202200362. [PMID: 35867602 PMCID: PMC9542358 DOI: 10.1002/cssc.202200362] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 06/01/2022] [Indexed: 05/10/2023]
Abstract
Mechanochemical transformations have made chemists enter unknown territories, forcing a different chemistry perspective. While questioning or revisiting familiar concepts belonging to solution chemistry, mechanochemistry has broken new ground, especially in the panorama of organic synthesis. Not only does it foster new "thinking outside the box", but it also has opened new reaction paths, allowing to overcome the weaknesses of traditional chemistry exactly where the use of well-established solution-based methodologies rules out progress. In this Review, the reader is introduced to an intriguing research subject not yet fully explored and waiting for improved understanding. Indeed, the study is mainly focused on organic transformations that, although impossible in solution, become possible under mechanochemical processing conditions, simultaneously entailing innovation and expanding the chemical space.
Collapse
Affiliation(s)
- Federico Cuccu
- Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Cagliari, Cittadella Universitaria, 09042, Monserrato, Cagliari, Italy
| | - Lidia De Luca
- Dipartimento di Chimica e Farmacia, Università degli Studi di Sassari, via Vienna 2, 07100, Sassari, Italy
| | - Francesco Delogu
- Dipartimento di Ingegneria Meccanica, Chimica e dei Materiali, Università degli Studi di Cagliari, Via Marengo 2, 09123, Cagliari, Italy
| | | | - Niclas Solin
- Department of Physics, Chemistry and Biology (IFM), Electronic and Photonic Materials (EFM), Building Fysikhuset, Room M319, Campus, Valla, Sweden
| | - Rita Mocci
- Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Cagliari, Cittadella Universitaria, 09042, Monserrato, Cagliari, Italy
| | - Andrea Porcheddu
- Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Cagliari, Cittadella Universitaria, 09042, Monserrato, Cagliari, Italy
| |
Collapse
|