نتایج جستجو برای: aryl aldehydes

تعداد نتایج: 22250  

Journal: :Angewandte Chemie 2014
Jeffrey S Arnold Edward T Mwenda Hien M Nguyen

Dynamic kinetic asymmetric amination of branched allylic acetimidates has been applied to the synthesis of 2-alkyl-dihydrobenzoazepin-5-ones. These seven-membered-ring aza ketones are prepared in good yield with high enantiomeric excess by rhodium-catalyzed allylic substitution with 2-amino aryl aldehydes followed by intramolecular olefin hydroacylation of the resulting alkenals. This two-step ...

Journal: :Chemical record 2017
Mingsheng Xie Lili Lin Xiaoming Feng

In this review, the recent developments in catalytic asymmetric inverse-electron-demand hetero-Diels-Alder reaction, which is recognized as one of the most powerful routes to construct highly functionalized and enantioenriched six-membered heterocycles, are described. The article is organized on the basis of different kinds of electron-deficient heterodienes, including α,β-unsaturated ketones/a...

2015
Masoumeh Sedighi Naser Montazeri

Cellulose sulfonic acid efficiently catalyzes the one-pot reaction of 4hydroxycoumarin and aryl aldehydes under mild reaction conditions to yield biscoumarin derivatives in high yields. This method is of great value because of its easy processing, short reaction time and high yields. We anticipate the present method will receive the attention of medicinal chemists and be used for elaborate synt...

2010
M. C. Sharma D. V. Kohli Smita Sharma A. D. Sharma

Several substituted-benzimidazole 3-(4-{5-Amino-6-fluoro-1-[2'-(1H-tetrazole-5-yl)-biphenyl-4ylmethyl]-1H-benzoimidazol-2-yl}-phenyl) -2-(substituted)thiazolidin-4-one were synthesized by condensation of various steps with various substituted aryl aldehydes reaction. Elemental analysis, IR, 1HNMR and mass spectral data confirmed the structure of the newly synthesized compounds. Synthesized and ...

Journal: :Chemical communications 2014
Veejendra K Yadav Ashish K Verma Piyush Kumar Vijaykumar Hulikal

The application of 2-arylcyclopropylmethanols as substitutes to homoallyl aryl alcohols and their reactions with aliphatic aldehydes in the presence of SnCl4 in CH2Cl2 leads to an efficient Prins cyclization to generate cis-2,6-disubstituted tetrahydropyrans in high yields. The reaction is free from 2-oxonia-Cope rearrangement. This protocol was used to synthesize (±)-centrolobine in an overall...

Journal: :Organic & biomolecular chemistry 2008
Shenghai Guo Yuanhong Liu

An efficient and one-pot procedure for the synthesis of arylated and stereodefined allylic alcohols has been achieved through zirconium-mediated multicomponent coupling reactions of alkynes, aldehydes (or ketones), and aryl iodides. The subsequent intramolecular Friedel-Crafts reactions of these allylic alcohols catalyzed by Brønsted or Lewis acids afford highly substituted indenes and spiroind...

Journal: :Advanced Synthesis & Catalysis 2021

Oxidized active carbon (oAC) catalyses the formation of polysubstituted quinolines from o-vinyl anilines and aldehydes. The reaction proceeds in a cascade manner through condensation, electrocyclization dehydrogenation, gives access to wide range with alkyl and/or aryl substituents as demonstrated 40 examples. metal-free catalytic procedure allows heterogeneous protocol for synthesis various qu...

2002
Min Shi Chao-Qun Li Jian-Kang Jiang

In the Baylis-Hillman reaction of aryl aldehydes with phenyl vinyl ketone we have observed exclusive formation of diadducts 4, and that the yields of diadduct can reach 80% with increasing amounts of phenyl vinyl ketone. On the other hand, for phenyl acrylate and phenyl thioacrylate, only the normal Baylis-Hillman adduct was obtained. The effects of substituents were also examined and a plausib...

Journal: :Organic & biomolecular chemistry 2015
Benedikt Melzer Franz Bracher

Methoxy- and benzyloxy-substituted isoquinolines are regioselectively metalated at C-1 with the Knochel-Hauser base, subsequent trapping with aromatic aldehydes gives aryl(isoquinolin-1-yl)carbinols as building blocks for divergent syntheses of different types of benzylisoquinoline alkaloids. Photochemical cyclization of ortho-bromo analogues under reductive conditions gives oxoaporphine alkalo...

2013
Mohammad Bakherad Saeideh Jajarmi

ABSTRACT Copper-free, Pd/C-catalyzed, one-pot reaction of 2,3-dichloroquinoxaline with hydrazine hydrate, bromine, phenylacetylene, and a variety of aldehydes provides an efficient and direct method for the preparation of 1-aryl-4-(2-phenylethynyl)[1,2,4]triazolo[4,3-a]quinoxalines in water at 70 °C. This methodology involves the use of inexpensive reagents or catalysts, and thus permits a new ...

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