An efficient iron/acetic acid mediated one pot reductive cyclization protocol was successfully developed for the synthesis of acridinone and quinoline derivatives.

We report a microwave-assisted intramolecular anomeric protection (iMAP) of glucosamine, which facilitates concise transformation of 1,6-anhydroglucosamine into 1,6-anhydrogalactosamine and 1,6-anhydroallosamine. The iMAP simultaneously obviates both the O1 and O6 protection, and the differentiation between O3 and O4 can be well-controlled by the N2 functionality because of the hydrogen bonding between N2 and O4. Epimerization of O4 afforded the galactosamine derivative and that of O3 yielded allosamine.

An efficient, one-pot method for the synthesis of dibenzodiazepinone derivatives involving copper-catalyzed tandem C À N bond formation is reported. The use of various halo amide and 2-iodoaniline derivatives permitted the synthesis of an array of dibenzodiazepinone derivatives in moderate to good yields. Moreover, a dibenzodiazepinone derivative {2-(

Iron/acetic acid mediated synthesis of 6,7-dihydrodibenzo [b,j] [1,7]phenanthroline derivatives via intramolecular reductive cylization An efficient iron/acetic acid mediated intramolecular reductive cyclization protocol for the synthesis of novel 6,7dihydrodibenzo[b,j][1,7] phenanthroline derivatives is described. In this two-step procedure, aldol addition and 10 reductive cyclization methods are effectively utilized for the construction of C-C and C-N bonds. This highly efficient process proceeds under mild conditions, tolerates different functional groups, and provides various substituted 6,7dihydrodibenzo [b,j] [1,7]phenanthroline derivatives in good 15 to excellent yields. In addition, various synthetic utilities of these derivatives are also described.

The unusual alcohol mediated formation of 4-oxo-2-aryl-4H-chromene-3-carboxylate (flavone-3-carboxylate) derivatives from 4-hydroxycoumarins and β-nitroalkenes in an alcoholic medium is described. The transformation occurs via the in situ formation of a Michael adduct, followed by the alkoxide ion mediated rearrangement of the intermediate. The effect of the different alcohol and nonalcohol media on the reaction was investigated.