New multicomponent domino reactions of arylglyoxals with pyrazol-5-amines have been established, providing selective access to unprecedented pyrazolo-fused 1,7-naphthyridines, 1,3-diazocanes, and pyrroles (up to 52 examples). The unreported dipyrazolo-fused 1,7-naphthyridines were regioselectively synthesized through a special double [3 + 2 + 1] heteroannulation accompanied by direct C-C format...

An efficient combination between the Passerini three-component reaction and aldol condensation has been developed for the synthesis of bicyclic isocoumarins with different substituted patterns via solvent-dependent domino pathways. These two operationally friendly methods simultaneously install C-O and C-C bonds in a one-pot manner, allowing the utilization of low-cost and readily accessible 2-...

A facile synthesis of highly functionalized 2H-iminopyran derivatives by the multi-component reaction of cyclohexyl isocyanide, dialkyl acetylenedicarboxylates, arylglyoxals and arylamines is described. The zwitterionic intermediate produced by addition of cyclohexyl isocyanide to electron-deficient acetylene diesters was trapped by the electrophilic imine moiety of α-iminoketones, derived from...

A new, simplified method for the synthesis of dimethyl aryl acylsulfonium salts has been developed. A series of dimethyl aryl acylsulfonium bromides were prepared by the reaction of aryl methyl ketones with hydrobromic acid and dimethylsulfoxide (DMSO). This sulfonium salt confirms that bromine production and the bromination reaction take place in the DMSO-HBr oxidation system. What's more, it ...

A novel four-component bicyclization strategy has been established, allowing a flexible and practical approach to 37 examples of multicyclic pyrazolo[3,4-b]pyridines from low-cost and readily accessible arylglyoxals, pyrazol-5-amines, aromatic amines, 4-hydroxy-6-methyl-2H-pyran-2-one, and cyclohexane-1,3-diones. The polysubstituted cyclopenta[d]pyrazolo[3,4-b]pyridines were stereoselectively s...

A simple and efficient synthesis of some polyfunctionalized pyrrole derivatives by a triphenylphosphine-promoted condensation reaction between dialkyl acetylenedicarboxylates, arylglyoxals, and ammonium acetate is described. This present  method carries several advantages, such as good yields, a simple procedure, non-hazardous reaction conditions and starting from easily accessible...

A new and improved protocol for the synthesis, in good to excellent yields, of acridine-1,8(2H,5H)-diones is described, involving a one-pot, three component reaction of dimedone, arylglyoxals, and ammonium acetate in water under microwave irradiation.