نتایج جستجو برای: phosphorus ylide

تعداد نتایج: 41924  

Journal: :Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology 2015
Qiu Sun Chang Jiang Yao Burkhard König

Aryl chalcones rearrange and add methanol to give substituted propane-1-ones upon UV-A irradiation in the presence of PPh3. We propose two possible mechanisms for this photo-rearrangement. The reaction involves either the formation of a phosphine-carbonyl intermediate, nucleophilic addition of MeOH and 1,2-aryl migration or the formation of ylide and carbene intermediates. The intermediates tra...

Journal: :Chemical science 2015
Rebecca L Grange Elizabeth A Clizbe Emma J Counsell P Andrew Evans

We have devised a highly regio- and enantioselective iridium-catalyzed allylic amination reaction with the sulfur-stabilized aza-ylide, S,S-diphenylsulfilimine. This process provides a robust and scalable method for the construction of aryl-, alkyl- and alkenyl-substituted C-chiral allylic sulfilimines, which are important functional groups for organic synthesis. Additionally, the combination o...

Journal: :Organic & biomolecular chemistry 2012
Shveta Pandiancherri Sarah J Ryan David W Lupton

Lewis base catalysed 1,3-dipolar cycloaddition between α,β-unsaturated acyl fluorides and N-[(trimethylsilyl)methyl]amino ethers has been achieved using 1 mol% DMAP. Competition experiments and (19)F-NMR studies indicate that the cycloaddition occurs preferentially between the α,β-unsaturated acyl fluoride and the unstabilised azomethine ylide. In addition, an enantioselective variant, using ch...

2008
Yaghoub Sarrafi Kamal Alimohammadi

The title compound, C(21)H(21)N(3)O(3), was synthesized by a multi-component 1,3-dipolar cyclo-addition of azomethine ylide, derived from isatin and proline by a deca-rboxylative route, and (E)-1-phenyl-2-nitro-propene. In the mol-ecule, the spiro junction links a planar oxindole ring and a pyrrolidine ring in an envelope conformation. The mol-ecular packing is stabilized by an inter-molecular ...

Journal: :Molecules 2015
Natarajan Arumugam Abdulrahman I Almansour Raju Suresh Kumar J Carlos Menéndez Mujeeb A Sultan Usama Karama Hazem A Ghabbour Hoong-Kun Fun

A series of hitherto unreported anthracene-embedded dispirooxindoles has been synthesized via a one-pot three-component 1,3-dipolar cycloaddition reaction of an azomethine ylide, generated in situ from the reaction of isatin and sarcosine to 10-benzylideneanthracen-9(10H)-one as a dipolarophile in 1-butyl-3-methylimidazolium bromide([bmim]Br), an ionic liquid. This reaction proceeded regio- and...

Journal: :Organic & biomolecular chemistry 2015
Ravindra B Pathak Benjamin C Dobson Nandita Ghosh Khalid A Ageel Madeha R Alshawish Rungroj Saruengkhanphasit Iain Coldham

An efficient synthetic approach to the core structure of the manzamine alkaloids is reported, particularly in relation to incorporating a one-carbon unit in ring B from which the aldehyde in ircinal A or the beta-carboline unit in manzamine A could potentially be generated. The key steps involve a Johnson-Claisen rearrangement, enolate alkylation, dithiane alkylation and a stereoselective intra...

Journal: :The Journal of organic chemistry 2006
Douglass F Taber Christopher G Nelson

The preparation of potassium hydride as a 1:1 homogenate with paraffin, termed KH(P), is reported. KH(P), a solid at room temperature, is stable without special handling. On suspension in THF with a phosphonium salt, KH(P) rapidly generates the ylide. Wittig condensation with aromatic, aliphatic, and alpha,beta-unsaturated aldehydes proceeds with high Z selectivity. KH(P) should be a generally ...

Journal: :Chemical communications 2014
Xiaotong Jing Fabiao Yu Lingxin Chen

We have presented a near-infrared fluorescent probe Lyso-JN for the detection of nitroxyl (HNO) in cells and in vivo. Lyso-JN is comprised of three moieties: an Aza-BODIPY fluorophore, a HNO-response modulator, diphenylphosphino-benzoyl, and a lysosomal locator, alkylmorpholine. The detection mechanism is based on aza-ylide intramolecular ester aminolysis reaction with HNO. The probe holds the ...

Journal: :Angewandte Chemie 2015
Shingo Ito Yuki Tokimaru Kyoko Nozaki

A novel nitrogen-doped corannulene derivative, 8-tert-butyl-6b(2) -azapentabenzo[bc,ef,hi,kl,no]corannulene, was synthesized by 1,3-dipolar cycloaddition of a polycyclic aromatic azomethine ylide with a diarylethyne and subsequent palladium-catalyzed intramolecular cyclization. This molecule represents the first example of a corannulene derivative bearing an internal heteroatom, and exhibits un...

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