Application of Biginelli reaction to the synthesis of ferrocenylpyrimidones and [3]-ferrocenophane-containing pyrimido[4,5-d]pyrimidinediones
摘要:
A series of ferrocene-containing mono- and bis-dihydropyrimidines (DHP's) were prepared by boric acid mediated three-component Biginelli reactions of formyl- and 1,1'-diformylferrocene, 1,3-dioxo-components and urea. A few further transformations including hydrogenolysis of a benzyl 4-ferrocenyl-DHP-5-carboxylate were also performed. Novel cis-fused saturated pyrimido[4,5-d]pyrimidine-2,7(1H, 3H)-diones incorporating [3]-ferrocenophane moiety were constructed by means of iron(III)-catalyzed Biginelli-like condensations of 1,1'-diformylferrocene with urea and in situ generated methyl ketone-derived silyl enol ethers. The structures of the new compounds were established by IR and NMR spectroscopy, including HMQC, HMBC and DEPT measurements. (C) 2009 Elsevier B. V. All rights reserved.