The Origin of Anion−π Autocatalysis

Article Article scientifique Article The Origin of Anion−π Autocatalysis eng 2023-03-17 2023-04-24 author Gutierrez Lopez Maria De Los Angèles Department of Organic Chemistry, University of Geneva, CH-1211 Geneva, Switzerland 952755 Département de chimie organique (CHIOR) author Tan Meiling Department of Organic Chemistry, University of Geneva, CH-1211 Geneva, Switzerland 973529 Département de chimie organique (CHIOR) author Frontera Antonio 0000-0001-7840-2139 Departament de Química, Universitat de les Illes Balears, SP-07122 Palma de Mallorca, Spain author Matile Stefan 0000-0002-8537-8349 Department of Organic Chemistry, University of Geneva, CH-1211 Geneva, Switzerland 129654 Département de chimie organique (CHIOR) 1039-1051 10.1021/jacsau.2c00656 2691-3704 https://pubs.acs.org/doi/10.1021/jacsau.2c00656 The autocatalysis of epoxide-opening ether cyclizations on the aromatic surface of anion−π catalysts stands out as a leading example of emergent properties expected from the integration of unorthodox interactions into catalysis. A working hypothesis was proposed early on, but the mechanism of anion−π autocatalysis has never been elucidated. Here, we show that anion−π autocatalysis is almost independent of peripheral crowding in substrate and product. Inaccessible asymmetric anion−π autocatalysis and sometimes erratic reproducibility further support that the origin of anion−π autocatalysis is more complex than originally assumed. The apparent long-distance communication without physical contact calls for the inclusion of water between substrate and product on the catalytic aromatic surface. Efficient anion−π autocatalysis around equimolar amounts but poor activity in dry solvents and with excess water indicate that this inclusion of water requires high precision. Computational models suggest that two water molecules transmit dual substrate activation by the product and serve as proton shuttles along antiparallel but decoupled hydrogen-bonded chains to delocalize and stabilize evolving charge density in the transition state by “anion−π double bonds”. This new transition-state model of anion−π autocatalysis provides a plausible mechanism that explains experimental results and brings anion−π catalysis to an unprecedented level of sophistication. Dewey 540 36 Département de chimie organique 141 false 761 Groupe Matile JACS Au 3 4 c022af8c-ef68-44b8-bd34-38ea79b485a7 Article (Published version) Public Article-scientifique-from-unpaywall.pdf 3140191 application/pdf CC BY dae1be28a35861578d826d581164cfd2ec4182d3b68a3e7e29015646d20b7d61 Vignette Public images_large_au2c00656_0011.jpg 214308 openAccess Faculté des sciences / Section de chimie et biochimie / Département de chimie organique

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The Origin of Anion−π Autocatalysis	JACS Au			2023	119	305

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