A new synthetic approach is described for building the coumarin scaffold through the Lewis acid‐promoted cyclization of novel aryl 3‐(dimethylamino)prop‐2‐enoates 2a–2f. The latter precursors were prepared via aminomethylenation of the corresponding aryl acetates 4a–4f with the Bredereck reagent. This approach was used for the synthesis of biologically active natural compounds 1a–1f, through a three‐step procedure starting from the corresponding phenols.

A highly efficient and regioselective synthesis of 1,2-dihydroquinolines via a multicomponent reaction between an aniline and two ketones is described. This reaction was catalyzed by magnesium bromide and carried out under solvent-free conditions. When the reaction was performed by using 3-substituted anilines and nonsymmetrically substituted ketones, principally a single product was found among the four expected regioisomers. A variety of anilines and ketones, including cyclic ketones, were evaluated providing a series of 1,2-dihydroquinolines with diverse substitution patterns. A study of the mechanism is discussed. There is evidence of the in situ formation of the imine as a result of the reaction between the aniline and one of the ketones, before annulation to the heterocyclic ring.

An efficient synthetic approach to the substituted benzo[b]furan and benzo[b]thiophene scaffolds by iodine‐mediated cyclization of the corresponding enaminones is described. This protocol was applied to a large series of these latter precursors to afford the respective benzoheterocycles substituted at the C‐2 position by a carbonyl group functionality. A study of the factors that control this process reveals that the reactivity depends on the presence of electron‐donor groups in the aryl ring of the aryloxycarbonylic and arylthiocarbonylic moieties.

Synthesis of Nuevamine Aza-Analogues by a Sequence: I-MCR-Aza-Diels--Alder-Pictet-Spengler. -A one-pot procedure including Ugi three-component reaction, aza-Diels-Alder cycloaddition and aromatization provides key intermediates (V). They are converted to alkaloid scaffolds of type (VI) by S-oxidation, acyloxysulfonium β-elimination and Pictet-Spengler cyclization. -(ISLAS-JACOME, A.; CARDENAS-GALINDO, L. E.; JEREZANO, A. V.; TAMARIZ, J.; GONZALEZ-ZAMORA, E.; GAMEZ-MONTANO*, R.; Synlett 2012, 20, 2951-2956, http://dx.doi.org/10.1055/s-0032-1317622 ; Dep. Quim., Univ. Guanajuato, 36050 Guanajuato, Mex.; Eng.) -Mais 17-152