Oxalylacetylenes act as dielectrophiles in the annulation of quinolines with highly functionalized 1,3-oxazine cycle decorated by the ethynyl, oxalyl, ester and aryl substituents. The annulation proceeds under mild condition (room temperature, without catalysts) in 2:1 mode with respect to acetylene and quinoline to deliver 1,3-oxazinoquinolines in 45-88% yields. A beneficial feature of the reaction is that, in contrast to results on the reaction of quinolines with trifluoroacetylacetylenes in the presence of water, where H2O acted as a third electrophile, this reaction well tolerates the aqueous medium. This reaction tolerates also isoquinoline and phenanthridine.

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Acylethynylpyrroles, now readily available by the cross-coupling of pyrroles with acylbromoacetylenes in solid Al2O3 media, in the presence of 1-methylimidazole underwent unprecedentedly easy (40–45 °C) cyclodimerization into bis(acylmethylidene)dipyrrolo[1,2-a:1′,2′-d]pyrazines in up to 51% yield. Some other organic and inorganic basic catalysts can also trigger this cyclodimerization, but less efficiently.

Early unknown pharmaceutically oriented heterocyclic systems of benzo[1,4]diazocinone/pyrrole ensembles have been synthesized in up to 93 % yields by the catalyst‐free mild insertion of pyrrolylacetylenic ketones into benzimidazoles. The reaction represents an extraordinary easy expansion of the aromatic five‐membered heterocyclic ring up to pyrrole‐ringed, highly unsaturated eight‐membered heterocyclic system. The proposed mechanism of the reaction proceeding through dipole and ylide intermediates is confirmed by quantum chemical calculations (DFT).

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