Indolinol-catalyzed asymmetric Michael reaction of aldehydes to nitroalkenes in brine
作者:Xin Hu、Yi-Fei Wei、Nan Wu、Zhiguo Jiang、Can Liu、Ren-Shi Luo
DOI:10.1016/j.tetasy.2016.03.006
日期:2016.6
(2S,3aS,7aS)-Perhydroindolinol A facilitated the reaction of a wide range of aldehyde and nitroalkene substrates to provide Michael adducts with excellent enantioselectivities (up to 98% ee), excellent yields and high diastereoselectivities (syn/anti up to 99:1). Our results indicated that perhydroindolinols were also highly efficient organocatalysts for asymmetric Michael reactions in brine, while also being environmentally friendly. (C) 2016 Elsevier Ltd. All rights reserved.
Asymmetric Conjugate Addition of Unmodified Propionaldehyde to β- Nitrostyrenes Catalyzed by Readily Available Proline-Based Dipeptidols
作者:Ren-Yong Yang、Chao-Shan Da、Lei Yi、Feng-Chun Wu、Hong Li
DOI:10.2174/157017809787003061
日期:2009.1.1
Organocatalytic asymmetric additions of unmodified aldehydes to β-nitrostyrenes are important carbon-carbon bond formation reactions and have become very attractive recently, because they are metal-free and environmentally benign. This work employed a series of L-proline-based diphenyl dipeptidols to catalyze this reaction. The results showed that these dipeptidols were effective organocatalysts with the yield up to 99%. 3a was optimal with the highest enantioselectivity up to 75% and dr (syn/anti) up to 94/6. In addition, the mechanism of this asymmetric reaction is also discussed.
Calcium carbonate as heterogeneous support for recyclable organocatalysts
作者:Carlos Lizandara-Pueyo、Xinyuan Fan、Carles Ayats、Miquel A. Pericàs
DOI:10.1016/j.jcat.2020.11.013
日期:2021.1
The controlled synthesis of calcium carbonate particles surface-functionalized with azido groups and its subsequent copper-catalyzed alkyne-azide cycloaddition (CuAAC) reactions with organocatalystsbearing alkyne anchors allowed the preparation of novel catalytic materials. A calcium carbonate-supported α,α-diarylprolinol silyl ether prepared in this manner catalyzes Michaeladdition of aldehydes to
intermediate, were used as chiral organocatalysts in asymmetricMichaeladditionreactions of aldehydes to nitroolefins. These proline-like catalysts are unique for their rigid bicyclic structure with two H atoms attached to the bridgehead C atoms lying on the opposite side of the ring. They therefore showed high efficiency in asymmetricMichaeladditions of aldehydes to nitroolefins. Under the optimal conditions
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