No abstract

The present microreview summarizes our progresses over the last years in the chemistry of 1,2‐diaza‐1,3‐dienes. Beyond the findings reported here, the main target of this microreview is to outline some of the reactive peculiarities that make this class of compounds powerful tools in heterocyclic chemistry. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

No abstract

The preparation of tetrahydropyrazines, dihydropyrazines, pyrazines, piperazinones, and quinoxalines by 1,4-addition of 1,2-diamines to 1,2-diaza-1,3-butadienes bearing carboxylate, carboxamide, or phosphorylated groups at the terminal carbon and subsequent internal heterocyclization is described. The solvent-free reaction of carboxylated 1,2-diaza-1,3-butadienes with the same reagents affords piperazinones, while phosphorylated 1,2-diaza-1,3-butadienes yield phosphorylated pyrazines. The solid-phase reaction of polymer-bound 1,2-diaza-1,3-butadienes with 1,2-diamines produces pyrazines.

No abstract

The synthesis of new lipophilic meso-tetraarylporphyrins bearing cardanol is described; cardanol is both a dangerous pollutant and renewable, widely available, relatively low-cost natural material obtained as a byproduct of the cashew industry for the edible use of cashew kernel. Such compounds exhibited unusual chemical and physico-chemical properties.

A very simple domino reaction under solvent-free conditions of various pyridine-like heterocycles with 1,2-diaza-1,3-dienes produces in good yields imidazo[1,2-a]pyridines, imidazo[1,2-a]quinolines, and imidazo[2,1-a]isoquinolines. The advantage of this one-pot transformation lies in the use of simple pyridine-like compounds without prefunctionalization of the starting heterocycles.

A novel three-component synthesis of 5-hydrazinoalkylidene rhodanine derivatives starting from aliphatic primary amines, carbon disulfide, and 1,2-diaza-1,3-dienes is described. The reaction proceeds successfully under both solution and solid-phase conditions.