- A flexible, convergent approach to piperidines, pyridines, azepines, and related derivatives
-
A highly convergent approach has been developed for the construction of various nitrogen heterocycles using as the key step the intermolecular addition of an α-ketonyl radical onto a suitably protected allylic or homoallylic amine.
- Boivin, Jean,Pothier, Julien,Zard, Samir Z.
-
p. 3701 - 3704
(2007/10/03)
-
- Thermal Rearrangements of Cyclic Amine Ylides. IV. Rearrangement of β,γ-Unsaturated 1-Alkylpiperidine N-Oxides: Formation of 1,2-Oxazepine Derivatives
-
The thermolysis of 1-methyl-2-vinylpiperidine N-oxide (13) resulted in Meisenheimer rearrangement to give the hexahydro-1,2-oxazepine (23) and no -sigmatropic rearrangement product (24).Similarly, the 1-methyl-1,2,5,6-tetrahydropyridine N-oxide
- Sashida, Haruki,Tsuchiya, Takashi
-
p. 4117 - 4123
(2007/10/02)
-
- Regioselective Addition of Grignard Reagents to 1-Acylpyridinium Salts. A Convenient Method for the Synthesis of 4-Alkyl(aryl)pyridines
-
The addition of Grignard reagents to 1-acylpyridinium salts afforded 1-acyl-2-alkyl(aryl)-1,2-dihydropyridines and 1-acyl-4-alkyl(aryl)-1,4-dihydropyridines.The regioselectivity of this reaction, 1,2- vs. 1,4-addition, was examined and found to be dependent upon the structures of the Grignard reagent and the 1-acyl group.Pyridine, 2-picoline, and 3-picoline were studied, and in most cases, significant amounts of 1,4-addition occurred.When a catalytic amount of cuprous iodide was present, nearly exclusive 1,4-addition resulted.The crude 1,4-dihydropyridines were aromatized by heating with sulfur to provide 4-substituted pyridines and picolines in good yield and high isomeric purity.
- Comins, Daniel L.,Abdullah, Abdul H.
-
p. 4315 - 4319
(2007/10/02)
-