- Regioselective CH bond activation on stabilized nitrogen ylides promoted by Pd(II) complexes: Scope and limitations
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The orthopalladation of N-ylides [HxCyN-CHC-(O)Ar] (HxCyN = pyridine, benzylamine, imidazole, aniline, and phenylpyridine; Ar = aryl) has been studied. The incorporation of the Pd atom to these substrates is regioselective, since the orthopalladation is produced, in most of the cases, only at the aryl ring of the benzoyl group with concomitant C-bonding of the Nylide. The X-ray structure of one representative example is reported. Factors governing the observed orientation are discussed, because this regioselectivity is worthy of note, considering the deactivating nature of the carbonyl group. Two exceptions to the general trend have been observed. The first one is the double metalation of the ylide [PhMe2NCHC(O)Ph], which incorporates one Pd at each Ph. The second one is the palladation of the phenylpyridine derivative, which occurs at the pyridinic 2-phenyl ring and produces a six-membered palladacycle.
- Grande, Loreto,Serrano, Elena,Cuesta, Luciano,Urriolabeitia, Esteban P.
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p. 394 - 404
(2012/04/23)
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- Experimental and quantum chemical evidences for C-H···N hydrogen bonds involving quaternary pyridinium salts and pyridinium ylides
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The rates of equilibrium of eight quaternary pyridinium salts containing activated methylene groups with the corresponding ylides have been measured in DMSO solution containing strong bases (DBU, MTBD and P1-tBu). The effect of the ring substituents on th
- Dega-Szafran,Schroeder,Szafran,Szwajca,L?ska,Lewandowska
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