Boron-Wittig olefination with gem-bis(boryl)alkanes

2021 ◽  
Author(s):  
Ana B. Cuenca ◽  
Elena Fernández
Keyword(s):  
Wittig Reaction ◽  
Carbonyl Derivatives ◽  
Wittig Olefination

Boron-Wittig reaction as the condensation of lithium α-bis(boryl)carbanions with carbonyl derivatives on route to substituted borylalkenes.

scholarly journals A Wittig-olefination–Claisen-rearrangement approach to the 3-methylquinoline-4-carbaldehyde synthesis

2012 ◽  
Vol 8 ◽  
pp. 1725-1729 ◽  
Author(s):  
Mukund G Kulkarni ◽  
Mayur P Desai ◽  
Deekshaputra R Birhade ◽  
Yunus B Shaikh ◽  
Ajit N Dhatrak ◽  
...  
Keyword(s):  
Efficient Method ◽  
Wittig Reaction ◽  
Claisen Rearrangement ◽  
Aldehyde Group ◽  
Oxidative Cleavage ◽  
Reductive Cyclization ◽  
Vinyl Ethers ◽  
Terminal Olefin ◽  
Wittig Olefination ◽  
Step Procedure

Efficient syntheses are described for the synthetically important 3-methylquinoline-4-carbaldehydes 6a–h from o-nitrobenzaldehydes 1a–h employing a Wittig-olefination–Claisen-rearrangement protocol. The Wittig reaction of o-nitrobenzaldehydes with crotyloxymethylene triphenylphosphorane afforded crotyl vinyl ethers 2a–h, which on heating under reflux in xylene underwent Claisen rearrangement to give 4-pentenals 3a–h. Protection of the aldehyde group of the 4-pentenals as acetals 4a–h and subsequent oxidative cleavage of the terminal olefin furnished nitroaldehydes 5a–h. Reductive cyclization of these nitroaldehydes yielded the required 3-methylquinoline-4-carbaldehydes 6a–h in excellent yields. Therefore, an efficient method was developed for the preparation of 3-methylquinoline-4-carbaldehydes from o-nitrobenzaldehydes in a simple five-step procedure.

scholarly journals Solvent reduced wittig olefination reactions with halo containing conjugated phosphoranes

2006 ◽  
Vol 4 (3) ◽  
Author(s):  
Thies Thiemann ◽  
Yasuko Tanaka ◽  
Keiko Ideta ◽  
Shuntaro Mataka
Keyword(s):  
Wittig Reaction ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Analogous Reaction ◽  
Cross Coupling Reaction ◽  
Wittig Olefination ◽  
Olefination Reactions

AbstractThe Wittig reaction of carbaldehydes with alkoxycarbonylhalomethylidenetriphenylphosphoranes can be performed with ease in solventless systems. The analogous reaction of carbaldehydes with acylhalomethylidenetriphenylphosphoranes requires a small amount of solvent, such as chloroform, in order for the reaction to proceed. The products of the reaction are versatile precursors for further transformations, such as the Suzuki-Miyaura cross-coupling reaction.

scholarly journals Characterization and Synthesis of Some α, β-unsaturated Ester Derivatives from Aliphatic Aldehydes

2010 ◽  
Vol 2 (2) ◽  
pp. 343-350
Author(s):  
M. A. Bari ◽  
M.M. Karim ◽  
M. M. Hoque ◽  
M. A. J. Miah
Keyword(s):  
Large Scale ◽  
Wittig Reaction ◽  
Acid Ethyl Ester ◽  
Aliphatic Aldehyde ◽  
Diazo Compounds ◽  
Unsaturated Ester ◽  
Reaction Conditions ◽  
Wittig Olefination ◽  
Synthetic Intermediates

Ethyl diazoacetate compound is useful synthetic intermediates for α, β-unsaturated ester in organic synthesis but, due to its toxicity and unpredictable explosive behaviour, its unique reactivity has not been fully exploited and the use on large scale has been avoided. We have developed a reliable method that generates EDA compound in situ. Our approach is based on the Wittig reaction, which utilizes EDA as diazo precursors. In the presence of Cu(OTf)2, we found that diazo compounds can be cleanly converted to alkenyl compounds under mild reaction conditions and in a narrow range of solvents. These diazo compounds can then be induced to react directly with aldehydes to synthesize olefin. We have shown the usefulness of this chemistry in a number of different transformations, such as Wittig olefination reactions chemistry as applied toward the synthesis of more complicated molecules. Keywords:  α, β-unsaturated ester; Acryclic acid ethyl ester; Aliphatic aldehyde; Cu(II) triflate; Triphenylphosphine. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i2.4167               J. Sci. Res. 2 (2), 343-350 (2010) 

Facile Synthesis of (E)-5-Styrylpyrimidines via Wittig Reaction Using So-dium Tripolyphosphate in Water

2020 ◽  
Vol 17 ◽  
Author(s):  
Anilkumar S. Patel ◽  
Sahaj A. Gandhi ◽  
Rajesh D. Modh ◽  
Urmila H. Patel ◽  
Yogesh T. Naliapara ◽  
...  
Keyword(s):  
Wittig Reaction ◽  
Sodium Tripolyphosphate ◽  
Facile Synthesis ◽  
Aryl Aldehydes ◽  
Wittig Olefination ◽  
High Yields ◽  
Very High

Abstract: An inexpensive and eco-friendly Wittig olefination protocol has been developed to prepare novel (E)-5-styrylpy-rimidines. The reaction of pyrimidine phosphonium ylide with different aryl/hetero-aryl aldehydes underwent smoothly in the presence of sodium tripolyphosphate (STPP) in aqueous condition giving (E)-5-styrylpyrimidines (10a-t) in very high yields (77-96 %).

Double Ring-Closing Approach for the Synthesis of 2,3,6,7-Substituted Anthracene Derivatives

2020 ◽  
Author(s):  
Birgit Meindl ◽  
Katharina Pfennigbauer ◽  
Berthold Stöger ◽  
Martin Heeney ◽  
Florian Glöcklhofer
Keyword(s):  
Wittig Reaction ◽  
Condensation Reaction ◽  
Synthetic Methods ◽  
Anthracene Derivative ◽  
Double Ring ◽  
Mild Conditions ◽  
Wide Range ◽  
Anthracene Derivatives

Anthracene derivatives have been used for a wide range of applications and many different synthetic methods for their preparation have been developed. However, despite continued synthetic efforts, introducing substituents in some positions has remained difficult. Here we present a method for the synthesis of 2,3,6,7-substituted anthracene derivatives, one of the most challenging anthracene substitution patterns to obtain. The method is exemplified by the preparation of 2,3,6,7-anthracenetetracarbonitrile and employs a newly developed, stable protected 1,2,4,5-benzenetetracarbaldehyde as the precursor. The precursor can be obtained in two scalable synthetic steps from 2,5-dibromoterephthalaldehyde and is converted into the anthracene derivative by a double intermolecular Wittig reaction under very mild conditions followed by a deprotection and intramolecular double ring-closing condensation reaction. Further modification of the precursor is expected to enable the introduction of additional substituents in other positions and may even enable the synthesis of fully substituted anthracene derivatives by the presented approach.<br>

Drug Design of Inhibitors of Alzheimer’s Disease (AD): POM and DFT Analyses of Cholinesterase Inhibitory Activity of β-amino di-Carbonyl Derivatives

2019 ◽  
Vol 19 (8) ◽  
pp. 688-705
Author(s):  
Taibi Ben Hadda ◽  
Abdur Rauf ◽  
Hsaine Zgou ◽  
Fatma Sezer Senol ◽  
Ilkay Erdogan Orhan ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cholinesterase Inhibitors ◽  
Metal Accumulation ◽  
Microtiter Plate ◽  
Metal Chelation ◽  
Carbonyl Derivatives ◽  
Cholinesterase Inhibitory Activity ◽  
Inhibitory Potential

Background:Since deficit of acetylcholine has been evidenced in the Alzheimer’s disease (AD) patients, cholinesterase inhibitors are currently the most specified drug category for the remediation of AD.Method:In the present study, 16 compounds (1-16) with dicarbonyl skeletons have been synthesized and tested for their inhibitory potential in vitro against AChE and BChE using ELISA microtiter plate assays at 100 μg/mL. Since metal accumulation is related to AD, the compounds were also tested for their metal-chelation capacity.Results and Conclusion:All the investigated dicarbonyl compounds exerted none or lower than 30% inhibition against both cholinesterases, whereas compounds 2, 8 and 11 showed 37, 42, 41% of inhibition towards BChE, being the most active. The highest metal-chelation capacity was observed with compound 8 (53.58 ± 2.06%). POM and DFT analyses are in good harmonization with experimental data.

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