نتایج جستجو برای: 1 2 diketones

تعداد نتایج: 3934068  

2010
Hülya Şenöz Nazan Tunoğlu

Acylation reaction of a variety of cyclic ketones via acylation of the corresponding enamines is welldefined in the literature. Enamine acylation of carbonyl compounds is a significant synthetic method because of its mildness and the ease of preparing various β-diketones [1-4]. Acylation reactions are performed by means of converting enamines to the enaminoketones and subsequent hydrolysis of t...

Journal: :Chemical communications 2011
Chun-Rong Liu Ben-Hu Zhu Jun-Cheng Zheng Xiu-Li Sun Zuowei Xie Yong Tang

A pyridine-catalyzed ylide cyclization affording dihydrofurans and dihydropyrroles has been developed. In the presence of a catalytic amount of pyridine and Fe(Tcpp)Cl, α-ylidene-β-diketones and α,β-unsaturated imines react with diazoacetates providing dihydrofurans and dihydropyrroles respectively, in up to 96% yield with high diastereoselectivities.

2013
Yumeng Xi Boliang Dong Xiaodong Shi

Gold-catalyzed O-vinylation of cyclic 1,3-diketones has been achieved for the first time, which provides direct access to various vinyl ethers. A catalytic amount of copper triflate was identified as the significant additive in promoting this transformation. Both aromatic and aliphatic alkynes are suitable substrates with good to excellent yields.

2012
Sergei Žari Tiiu Kailas Marina Kudrjashova Mario Öeren Ivar Järving Toomas Tamm Margus Lopp Tõnis Kanger

The organocatalytic Michael addition of malonates to symmetric unsaturated 1,4-diketones catalyzed by thiourea and squaramide derivatives with Cinchona alkaloids afforded the formation of a new C-C bond in high yields (up to 98%) and enantiomeric purities (up to 93%). The absolute configuration of the product was suggested from comparison of the experimental and calculated VCD spectra of the re...

2012
Jérôme Husson Michael Knorr

Different synthetic routes leading to terpyridines functionalised with furan heterocycles are reviewed. The methodologies used to prepare such compounds include the ring closure of 1,5-diketones and cross-coupling reactions. These versatile terpyridines and their derived metal complexes find applications in various fields including coordination chemistry, medicinal chemistry and material sciences.

2016
Andreas Steinbacher Pramod Kumar Verma Federico Koch Patrick Nuernberger Tobias Brixner

The photodynamics in symmetric and unsymmetric β-diketones are studied with transient absorption in the deep-UV. Excitation leads to ultrafast ESIPT while further relaxation and isomerization processes depend on the molecular symmetry and solvent environment. OCIS codes: (320.7150) Ultrafast spectroscopy; (300.6540) Spectroscopy, ultraviolet; (190.7110) Ultrafast nonlinear optics

Journal: :Chemical communications 2009
David Tejedor Gabriela Méndez-Abt Javier González-Platas Miguel A Ramírez Fernando García-Tellado

Ambiphilic allenes are generated by an organocatalyzed domino reaction of alkyl propiolates and aromatic 1,2-diketones; in the absence of any external chemical agent, these allenes perform a thermally-driven dimerization reaction to generate the corresponding fully-substituted cyclobutanes in a regio- and highly stereoselective manner.

Journal: :Chemical communications 2013
Gemma C Geary Eric G Hope Kuldip Singh Alison M Stuart

The air and moisture stable fluoroiodane 8, readily prepared on a 6 g scale by nucleophilic fluorination of the hydroxyiodane 7 with TREAT-HF, has been used as an electrophilic fluorinating reagent for the first time to monofluorinate 1,3-ketoesters and difluorinate 1,3-diketones in good isolated yields.

Journal: :Chemical communications 2008
Dieter Enders Jianwei Han Alexander Henseler

The asymmetric intermolecular Stetter reaction is catalyzed by a novel triazolium salt derived N-heterocyclic carbene leading to 1,4-diketones in moderate to excellent yields (49-98%) and moderate to good enantioselectivities (56-78% ee), which could be enhanced by one recrystallization to excellent levels (90-99% ee).

Journal: :iranian journal of catalysis 2013
bahareh sadeghi fereshteh karimi

1,2-diketones have been reacted in one-pot method with 1,2-diamines at room temperature with zno nanoparticles as a catalyst. zno nanoparticles as an available and reusable catalyst is used for the synthesis of quinoxalinein improved yields.

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