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[摘要]：Two highly efficient and general one-pot annulation reactions are described for the synthesis of imidazopyridine derivs. (IPs). The two procedures are complementary to each other: whereas the first one allows the prodn. of simpler IPs, the second leads to IPs with functionalized imidazole moiety. Both methodologies consist of an activation step, which raises the electrophilicity of the N-heterocyclic starting material (i.e., quaternization of the N-heterocycle), followed by a cascade reaction involving nucleophilic addn., substitution, rearrangement, and oxidn. steps. These methodologies can be used in the synthesis of a library of drug-like mols. The authors warn that the intermediates, e.g. N-(2-bromoethyl)phenanthridinium bromide, are extreme irritants and allergenics. |
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