82126-20-3Relevant articles and documents
Copper-Catalyzed multicomponent coupling of organoindium reagents with nitrogen-Containing aromatic heterocycles
Beveridge, Ramsay E.,Black, Daniel A.,Arndtsen, Bruce A.
experimental part, p. 3650 - 3656 (2010/09/03)
A mild, copper-catalyzed coupling of organoindium reagents with nitrogen-containing aromatic heterocycles and chloroformates is described. This reaction proceeds with a range of organoindium reagents, yielding predominately or exclusively the 1,4-addition products with pyridine. In addition, a range of other nitrogen-containing heterocycles can be employed in this reaction (e.g. benzoxazole, benzothiazole, phthalazine). As an illustration of the utility of this reaction, this heterocycle functionalization is coupled with a subsequent oxidation to achieve the one-pot synthesis of functionalized pyridine and benzothiazole derivatives.
A Convenient Method for the Regioselective Synthesis of 4-Alkyl(aryl)pyridines Using Pyridinium Salts
Akiba, Kin-ya,Iseki, Yuji,Wada, Makoto
, p. 1994 - 1999 (2007/10/02)
RCu.BF3 reacted with 1-ethocycarbonylpyridinium chloride at the 4-position with almost complete regioselectivity (>99percent) to afford the corresponding 1,4-dihydropyridine derivatives in high yields (81-94percent).The dihydropyridines were oxidized by oxygen to give 4-alkyl(aryl)pyridines (38-68percent).Grignard reagents also reacted with 1-t-butyldimethylsilylpyridinium triflate with almost complete regioselectivity (>99percent) to afford the corresponding 1,4-dihydropyridines, which were easily oxidized to give 4-substituted pyridines in higher yields than above (58-70percent).
Regioselective Addition of Grignard Reagents to 1-Acylpyridinium Salts. A Convenient Method for the Synthesis of 4-Alkyl(aryl)pyridines
Comins, Daniel L.,Abdullah, Abdul H.
, p. 4315 - 4319 (2007/10/02)
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.