2026-04-17T01:40:35Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/1427792025-12-04T21:45:33Zcom_2072_1057col_2072_478917col_2072_478933

00925njm 22002777a 4500 dc Cortes-Clerget, Margery author Jover Modrego, Jesús author Dussart, Jade author Kolodziej, Emilie author Monteil, Maelle author Migianu-Griffoni, Evelyne author Gager, Olivier author Deschamp, Julia author Lecouvey, Marc author 2019-10-22T11:43:43Z 2019-10-22T11:43:43Z 2017-05-11 2019-10-22T11:43:43Z Enamine catalysis is a widespread activation mode in the field of organocatalysis and is often encountered in bifunctional organocatalysts. We previously described H-Pro-Pro-pAla-OMe as a bifunctional catalyst for Michael addition between aldehydes and aromatic nitroalkenes. Considering that opposite selectivities were observed when compared to H-Pro-Pro-Glu-NH2, an analogue described by Wennemers, the activation mode of H-Pro-Pro-pAla-OMe was investigated through kinetic, linear effect studies, NMR analyses, and structural modifications. It appeared that only one bifunctional catalyst was involved in the catalytic cycle, by activating aldehyde through an (E)-enamine and nitroalkene through an acidic interaction. A restrained tripeptide structure was optimal in terms of distance and rigidity for better selectivities and fast reaction rates. Transition-state modeling unveiled the particular selectivity of this phosphonopeptide. Reaccions d'addició Teoria del funcional de densitat Catàlisi Addition reactions Density functionals Catalysis Bifunctional tripeptide with a phosphonic acid as a bronsted acid for Michael addition: mechanistic insights