The Role of Crystalline Intermediates in Mechanochemical Cyclorhodation Reactions Elucidated by in-Situ X-ray Powder Diffraction and Computation.

Autor: Hernández JG; Grupo Ciencia de los Materiales, Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia, Calle 70 No 52-21, Medellín, Colombia., Ardila-Fierro KJ; Grupo Ciencia de los Materiales, Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia, Calle 70 No 52-21, Medellín, Colombia., Gómez S; Scuola Normale Superiore, Classe di Scienze, Piazza dei Cavalieri 7, 56126, Pisa, Italy., Stolar T; Division of Physical Chemistry, Ruđer Bošković Institute, Bijenička c. 54, 10000, Zagreb, Croatia., Rubčić M; Faculty of Science Department of Chemistry, University of Zagreb, Horvatovac 102a, 10000, Zagreb, Croatia., Topić E; Faculty of Science Department of Chemistry, University of Zagreb, Horvatovac 102a, 10000, Zagreb, Croatia., Hadad CZ; Instituto de Química, Facultad de Ciencias Exactas y Naturales Universidad de Antioquia, UdeA, Calle 70 No 52-21, Medellín, Colombia., Restrepo A; Instituto de Química, Facultad de Ciencias Exactas y Naturales Universidad de Antioquia, UdeA, Calle 70 No 52-21, Medellín, Colombia.
Jazyk: angličtina
Zdroj: Chemistry (Weinheim an der Bergstrasse, Germany) [Chemistry] 2023 Sep 15; Vol. 29 (52), pp. e202301290. Date of Electronic Publication: 2023 Aug 16.
DOI: 10.1002/chem.202301290
Abstrakt: The occurrence of crystalline intermediates in mechanochemical reactions might be more widespread than previously assumed. For example, a recent study involving the acetate-assisted C-H activation of N-Heterocycles with [Cp*RhCl 2 ] 2 by ball milling revealed the formation of transient cocrystals between the reagents prior to the C-H activation step. However, such crystalline intermediates were only observed through stepwise intervallic ex-situ analysis, and their exact role in the C-H activation process remained unclear. In this study, we monitored the formation of discrete, stoichiometric cocrystals between benzo[h]quinoline and [Cp*RhCl 2 ] 2 by ball milling using in-situ synchrotron X-ray powder diffraction. This continuous analysis revealed an initial cocrystal that transformed into a second crystalline form. Computational studies showed that differences in noncovalent interactions made the [Cp*RhCl 2 ] 2 unit in the later-appearing cocrystal more reactive towards NaOAc. This demonstrated the advantage of cocrystal formation before the acetate-assisted metalation-deprotonation step, and how the net cooperative action of weak interactions between the reagents in mechanochemical experiments can lead to stable supramolecular assemblies, which can enhance substrate activation under ball-milling conditions. This could explain the superiority of some mechanochemical reactions, such as acetate-assisted C-H activation, compared to their solution-based counterparts.
(© 2023 Wiley-VCH GmbH.)
Databáze: MEDLINE
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