Asymmetric catalysis with chiral zeolite GTM materials: host-guest transfer of chirality

Abstract:

Heterogeneous asymmetric catalysts capable of producing chiral compounds in an enantiospecific manner represents a crucial challenge in our current society. The archetype of asymmetric catalysts is given by enzymes, where the chirality of L-aminoacids promotes the formation of asymmetric nanospaces where chirality is induced during a catalytic process. However, the excellent chiral catalytic performance of enzymes is hindered by their difficult recyclability and, especially, by the chiral limitation imposed by nature where only one enantiomer of a chiral product, dictated by the chiral selection of life, can be prepared. In this context, chiral zeolites have emerged as ideal candidates since they could combine their characteristic shape-selectivity with a potential enantio-selectivity that would be enhanced by the confinement effect. However, despite intensively searched for decades, only recently have enantio-enriched chiral zeolite materials been achieved through the use of chiral organic structure-directing agents. In this perspective, of remarkable relevance are the so-called GTM chiral zeolite materials that have been recently discovered in our laboratories.1-4 These materials, that have been produced from ephedrine and pseudoephedrine natural alkaloids as chiral inductors to build chiral organic structure-directing agents, display the -ITV framework structure, one of the most appealing zeolites since it combines the presence of extra-large and chiral pores, enabling the enantioselective processing of bulky chiral compounds, of great relevance in the pharma industry. These GTM materials have proved useful asymmetric catalysts for organic processes where chirality emerges from their chiral confined nanospace similar to that of enzymes.5 In this seminar I will summarize all the work performed in our lab on the discovery of these exceptional materials along the last years, including their synthesis, characterization and asymmetric catalytic activity, that has reached unprecedented enantiomeric excesses up to 88 %, now close to those reached by enzymatic systems, but with the crucial advantage associated to heterogeneous catalysts and especially the possibility of preparing both enantiomeric versions by using an easily accessible alkaloid.

[1] R. de la Serna, D. Nieto, R. Sainz, B. Bernardo-Maestro, Á. Mayoral, C. Márquez-Álvarez, J. Pérez-Pariente, L. Gómez-Hortigüela, J. Am. Chem. Soc. 144 (2022) 8249-8256.
[2] R. de la Serna, I. Arnaiz, C. Márquez-Álvarez, J. Pérez-Pariente, L. Gómez-Hortigüela, Chem. Commun. 58 (2022) 13083-13086.
[3] R. de la Serna, J. Pérez-Pariente, L. Gómez-Hortigüela, Catal. Today 426 (2024) 114389.
[4] R. de la Serna, J. Jurado-Sánchez, C. Márquez-Álvarez, J. Pérez-Pariente, L. Gómez-Hortigüela, Microporous Mesoporous Mater. 371 (2024) 113083.
[5] R. de la Serna, J. Jurado-Sánchez, J. Li, C. Márquez-Álvarez, J. Pérez-Pariente, L. Gómez-Hortigüela, ACS App. Mater. Inter. 40 (2024) 54067-54080.