TY  - JOUR
AU  - Hernandez, Jose
AU  - Ardila-Fierro, Karen J.
AU  - Gómez, Sara
AU  - Stolar, Tomislav
AU  - Rubčić, Mirta
AU  - Topić, Edi
AU  - Hadad, Cacier Z.
AU  - Restrepo, Albeiro
TI  - The Role of Crystalline Intermediates in Mechanochemical Cyclorhodation Reactions Elucidated by in‐Situ X‐ray Powder Diffraction and Computation
JO  - Chemistry - a European journal
VL  - 29
IS  - 52
SN  - 0947-6539
CY  - Weinheim
PB  - Wiley-VCH
M1  - PUBDB-2023-05174
SP  - e202301290
PY  - 2023
N1  - Waiting for fulltext 
AB  - 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<sub>2</sub>]<sub>2</sub> 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<sub>2</sub>]<sub>2</sub> 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<sub>2</sub>]<sub>2</sub> 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. 
LB  - PUB:(DE-HGF)16
C6  - 37347170
UR  - <Go to ISI:>//WOS:001049312100001
DO  - DOI:10.1002/chem.202301290
UR  - https://bib-pubdb1.desy.de/record/589418
ER  -