Translating the Enantioselective Michael Reaction to a Continuous Flow Paradigm with an Immobilized, Fluorinated Organocatalyst
作者:Irina Sagamanova、Carles Rodríguez-Escrich、István Gábor Molnár、Sonia Sayalero、Ryan Gilmour、Miquel A. Pericàs
DOI:10.1021/acscatal.5b01746
日期:2015.11.6
enantioselective, continuous flow processes allowing either the multigram synthesis of a single Michael adduct over a 13 h period or the sequential generation of a library of enantiopure Michael adducts from different combinations of substrates (13 examples, 16 runs, 18.5 h total operation). A customized in-line aqueous workup, followed by liquid–liquid separation in flow, allows for product isolation
Amine Catalysis with Substrates Bearing
<i>N</i>
‐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
Synthesis of <i>N</i>-alkylated lipopeptides and their application as organocatalysts in asymmetric Michael addition in aqueous environments
作者:José A. C. Delgado、Fidel E. M. Vicente、Alexander F. de la Torre、Vitor A. Fernandes、Arlene G. Corrêa、Márcio W. Paixão
DOI:10.1039/d1nj01112j
日期:——
through an isocyanide-based multicomponent reaction. Various structural motifs were tunably introduced on the catalyst backbone with the aim of incorporating amphiphilic features. Consequently, they have further been evaluated in the 1,4-addition of aldehydes to trans-β-nitrostyrene having water as the sole solvent. Under sustainable reactionconditions, Michael adducts were obtained in excellent yields
AbstractStereoselective Michael addition of enolizable carbonyl compounds to a furane-derived nitroalkene was catalyzed by di- and tripeptide organocatalysts. The most competent catalysts were tripeptides possessing Pro–Pro–Glu structure. With aldehydes, Michael adducts were obtained in high yields and with medium-to-high diastereo- (up to 13:1 d.r.) and enantiomeric purities (up to 99% ee). The reaction was less stereoselective
Organocatalytic asymmetric Michael addition of aldehydes and ketones to nitroalkenes catalyzed by adamantoyl <scp>l</scp>-prolinamide
作者:Yongchao Wang、Dong Li、Jun Lin、Kun Wei
DOI:10.1039/c4ra11214h
日期:——
series of adamantoyl L-prolinamides have been synthesized. These compounds have been found to be highly efficient organocatalysts for the Michaeladdition of aldehydes and ketones to nitroalkenes. Under the optimized reaction conditions, the corresponding Michael adducts were obtained in good yields (up to 95%), excellent enantioselectivities (up to 99% ee) and moderate diastereoselectivities.