Copper-Catalyzed Synthesis of Fused Imidazopyrazine N-Oxide Skeletons
Keyword(s):
N-Propargyl-2-aroylimidazoles synthesized and converted into the corresponding ketoximes. Under various conditions, several mono- and diketoxime imidazole derivatives were formed by converting the carbonyl or carbonyl and propargyl groups into oxime groups. N-Propargyl monooxime imidazole derivatives were cyclized by treatment with CuI to give various imidazopyrazine N-oxides. Several copper salts, such as CuOAc, CuSO4, and CuOTf, formed the same cyclization product. This cyclization reaction occurred only in the presence of Cu(I) or Cu(II) salts; other transition metals such as Au, Ag, In, and Fe did not yield cyclic products. The nucleus-independent chemical shift method was used to calculate the aromaticity of the bicyclic rings.
2008 ◽
Vol 80
(3)
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pp. 563-569
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2000 ◽
Vol 6
(8)
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pp. 1446-1454
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2009 ◽
Vol 74
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pp. 1105-1111
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2004 ◽
Vol 108
(49)
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pp. 10873-10896
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2008 ◽
Vol 854
(1-3)
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pp. 110
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