A novelbifunctional organocatalyst library combining both aminocatalysis and phosphonicacid activation was used for the first time as an efficient tool for the stereoselectiveMichaeladdition of aldehydes with several aromatic nitroalkenes with good selectivities up to 95:5 dr and 93:7 er. Due to their high water solubility, the catalysts were easilyrecyclable and could be reused over several cycles
Amine Catalysis with Substrates Bearing
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‐Heterocyclic Moieties Enabled by Control over the Enamine Pyramidalization Direction
作者:Jasper S. Möhler、Tobias Schnitzer、Helma Wennemers
DOI:10.1002/chem.202002966
日期:2020.12
Stereoselective organocatalytic C−C bond formations that tolerate N‐heterocycles are valuable since these moieties are common motifs in numerous chiral bioactive compounds. Such transformations are, however, challenging since N‐heterocyclic moieties can interfere with the catalytic reaction. Here, we present a peptide that catalyzes conjugateaddition reactions between aldehydes and nitroolefins bearing a
A versatile one‐step photopolymerization approach for the immobilization of enantioselectiveorganocatalysts is presented. Chiral organocatalyst‐containing monoliths based on polystyrene divinylbenzene copolymer were generated inside channels of microfluidic chips. Exemplary performance tests were performed for the monolithic Hayashi–Jørgensen catalyst in continuous flow, which showed good results
Enamine Catalysis in Flow with an Immobilized Peptidic Catalyst
作者:Yukihiro Arakawa、Helma Wennemers
DOI:10.1002/cssc.201200740
日期:2013.2
Pep talk: An immobilizedpeptidiccatalyst achieves more than 600 turnovers in a continuous‐flow system, allowing the production of chiral γ‐nitroaldehydes with excellent stereoselectivities on a scale of >450 mmol (>100 g). Such a high efficiency opens the way for more practical applications of enaminecatalysis.
Asymmetric Organocatalysis Accelerated via Self‐Assembled Minimal Structures
作者:Arianna Sinibaldi、Francesca Della Penna、Marco Ponzetti、Francesco Fini、Silvia Marchesan、Andrea Baschieri、Fabio Pesciaioli、Armando Carlone
DOI:10.1002/ejoc.202101042
日期:2021.10.21
Self-assembling minimalistic peptides embedded with an organocatalytic moiety were designed and tested in a Michael reaction as a proof of concept for acceleratedorganocatalysis.