Superparamagnetic Nanoparticle-Supported (S)-Diphenyl- prolinol Trimethylsilyl Ether as a Recyclable Catalyst for Asymmetric Michael Addition in Water
作者:Bang Gen Wang、Bao Chun Ma、Qiong Wang、Wei Wang
DOI:10.1002/adsc.201000508
日期:2010.11.22
A new superparamagneticnanoparticle-supported (S)-diphenylprolinol trimethylsilylether (Jørgensen–Hayashi catalyst) was synthesized and applied for the asymmetricMichaeladdition of aldehydes to nitroalkenes in water, which gives products in moderate to good yields (up to 96%), good enantioselectivity (up to 90% ee) and diastereoselectivities (up to 99:1). The immobilized catalyst could be easily
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
Synthesis of a bipyridine-derived achiral thiourea trifluoromethanesulfonic acid salt and its application as an additive in organocatalytic asymmetric reactions
作者:Ayhan Sıtkı Demir、Sinan Basceken
DOI:10.1016/j.tetlet.2013.08.004
日期:2013.10
The host–guest complex of a proline–thiourea bipyridine trifluoromethanesulfonic acidsalt can catalyze organocatalytic asymmetricreactions such as aldol, Michael, and Mannich in polar protic medium with high stereoselectivities. The privileged bipyridine backbone and the thiourea motif are essential to the activity and enantioselectivity through hydrogen bonding interactions.
be used as conformational control units of organocatalysts to tune their catalytic properties. New hybrid dipeptide‐like organocatalysts based on ζ‐sugar aminoacids and proline were prepared and tested for the asymmetric Michael addition of aldehydes to β‐nitrostyrenes. Taking full advantage of the modular nature of the carbohydrate motif, both reactivity and stereoselectivity were significantly improved
A novel bifunctional proline amide–carboxylic acid catalyst was used for the highly stereoselective Michael reaction of various aldehydes with different nitroalkenes. This catalyst was easily prepared using commonly available anhydrides and proline linked with a diamine spacer. The asymmetric catalytic Michael reactions afforded high yields (up to 98 %), diastereoselectivities ( ratio: up to 86:14)