- Activation of pyridinium salts for electrophilic acylation: A method for conversion of pyridines into 3-acylpyridines
-
Cyanide adducts of N-MOM pyridinium salts react with strong acylating reagents to provide 3-acyl-4-cyano-1,4-dihydropyridines that can be aromatized to 3-acylpyridines using ZnCl2 in refluxing ethanol.
- Klapars,Vedejs
-
-
Read Online
- Reaction of N-vinylic phosphazenes with α,β-unsaturated aldehydes. Azatriene-mediated synthesis of dihydropyridines and pyridines derived from β-amino acids
-
Aza-Wittig reaction of N-vinylic phosphazenes (1,2 addition), derived from diphenylmethylphosphine or derived from trimethylphosphine with α,β-unsaturated aldehydes, leads to the formation of 3-azatrienes through a [2 + 2]-cycloaddition-cycloreversion sequence. The presence of an alkyl substituent in position 3 of N-vinylic phosphazenes increases the steric interactions, and [4 + 2] periselectivity (1,4 addition) is observed. Reaction of azatrienes with α,β-unsaturated aldehydes yields pyridines.
- Palacios, Francisco,Herran, Esther,Alonso, Concepcion,Rubiales, Gloria,Lecea, Begona,Ayerbe, Mirari,Cossio, Fernando P.
-
p. 6020 - 6030
(2007/10/03)
-
- Immunopotentiator agents
-
Novel compounds and methods for preparing same, immunopotentiating compositions, and a method for potentiating the immune system of a host animal. The method comprises administering to the animal an effective amount of an immunopotentiating compound of Formula I or Formula II, or a physiologically acceptable salt.
- -
-
Page column 20
(2010/02/05)
-
- NMR Properties and Synthesis of Ring-methylated 1,4-Dihydronicotinamides and the Corresponding Pyridinium Salts. Correlation of NMR with Ab Initio STO-3G Results
-
The synthesis of a series of ring-methylated 1-alkyl-1,4-dihydronicotinamides and the corresponding pyridinium salts is described.Their NMR properties involving aromatic-ring-shielding anisotropy, due to ring current effects, are discussed and compared with electron populations calculated from STO-3G results.
- Bossaerts, Jan D.,Dommisse, Roger A.,Alderweireldt, Frank C.,Geerlings, Paul
-
p. 2360 - 2384
(2007/10/02)
-