نتایج جستجو برای: aza conjugate addition reaction

تعداد نتایج: 1122661  

Journal: :Advanced Synthesis & Catalysis 2021

The development of a stereoselective aza-Piancatelli reaction to access 4-aminocyclopentenones is reported. This transformation relies on the use chiral o-sulfinyl anilines as inductors afford targeted products in good excellent yields. Remarkably, high value-added cyclopentenones could be obtained drs up >95:5, depending upon furan substitution pattern.

Silica ferric hydrogensulfate is an efficient heterogeneous catalyst for the cyclization of 2- aminochalcones to the corresponding 2,3-dihydroquinolin- 4(1H)-ones. This intramolecular aza Michael reaction was carried out in high yields using chalcones bearing of electron donating and electron withdrawing groups. The catalyst is reusable without significant decreases in its activity after four t...

2008
Markus Weymann Horst Kunz

Initially, lasubin II was synthesized diastereoselectively in racemic form [3]. Asymmetric syntheses of lasubin II were achieved based on stereoselective transformations of enantiomerically pure substrates [4] or, for example, via a diastereoselective aza-Diels-Alder reaction using a resolved chiral arylaldehyde tricarbonylchromium complex [5]. Recently, an enantioselectively catalyzed aza-Diel...

Journal: :Molecules 2015
Chao Li Kun Jiang Ying-Chun Chen

An asymmetric annulation reaction of γ-butenolides and cyclic 1-azadienes containing a 1,2-benzoisothiazole-1,1-dioxide motif has been studied, proceeding in a tandem Michael addition-aza-Michael addition sequence. Endo-type cycloadducts bearing fused tetracyclic skeletons were isolated in fair yields and with high enantioselectivity (up to >99% ee) under the catalysis of modified cinchona alka...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2004
Matthew P Rainka Yimon Aye Stephen L Buchwald

A chiral copper-hydride catalyst for the asymmetric conjugate reduction of alpha,beta-unsaturated carbonyl compounds has been used for the reduction of substrates containing beta-nitrogen substituents. A new set of reaction conditions has allowed for a variety of beta-azaheterocyclic acid derivatives to be synthesized in excellent yields and with high degrees of enantioselectivity. In addition,...

Journal: :Journal of materials chemistry. A, Materials for energy and sustainability 2021

Double conjugate addition leads to an increased stability and voltage for this amine functionalised quinoidal anolyte designed basic aqueous redox flow batteries, suggesting that such a reaction does not always lead degradation.

Journal: :Chemical communications 2014
Shaoxia Lin Ling Li Fushun Liang Qun Liu

A novel and efficient method for the construction of γ-lactams with an all-carbon quaternary center is developed via a DABCO-catalyzed reaction of EWG-activated cyclopropanecarboxamides and electron-deficient alkenes. The process involves sequential ring-opening of activated cyclopropanes, intermolecular Michael addition and intramolecular aza-cyclization.

Journal: :Organic letters 2012
Biao Jiang Jue Wang Zuo-gang Huang

A stereocontrolled strategy toward the synthesis of nagelamide K has been developed. The dimeric imidazole acrylate, diimidazolidenesuccinate, was constructed as a synthetic precursor by a Ni-catalyzed coupling reaction; the microwave-promoted intramolecular aza-Michael addition afforded the imidazo[1,5-a]pyridine core structure of nagelamide K in high stereoselectivity. A detaurine-dediamino a...

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