No abstract

A condensação direta de benzeno-1,2-diaminas (4-R-Ph-(NH 2 ) 2 , onde R = H, Me, Cl e NO 2 ) e 1,2-dicarbonil (R'-CO-CO-R', onde R' = Ph, 4-MeO-Ph e Me) foi realizada com excelentes rendimentos (95-100%) usando (NH 4 Cl-CH 3 OH) como sistema catalítico brando, eficiente, de boa relação custo-benefício, fácil obtenção, isento de ácido e de metal e ambientalmente amigável, a temperatura ambiente. O procedimento pode ser realizado para diversas quinoxalinas e a natureza do grupo funcional no anel aromático das 1,2-diaminas exerce uma forte influência no tempo e rendimento da reação. A eficiência da condensação pode ser regulada também pela quantidade de catalisador e tempo de reação.The direct condensation of various benzene-1,2-diamines [4-R-Ph-(NH 2 ) 2 , where R = H, Me, Cl and NO 2 ] and 1,2-dicarbonyl compounds (R'-CO-CO-R', where R' = Ph, 4-MeO-Ph and Me) has been successfully achieved mostly in excellent yields (95-100%) using (NH 4 Cl-CH 3 OH) as a mild, efficient, cost-effective, readily available, acid-free, metal-free and eco-friendly catalyst system at room temperature. The procedure can be performed for a broad scope of quinoxalines, however, the nature of the functional group on the aromatic ring of 1,2-diamine exerts a strong influence on the time and the reaction yield. The condensation efficiency could be further regulated by the amount of catalyst and reaction time.

We describe the design and synthesis of some hypothetical heptapeptides specifically to overcome the neoplastic activity of ras oncogene and their anti-cancer activities were studied. To improve the anti-cancer activity of the synthesized peptides, their structure modifications were done based on a sequential Ugi/Huisgen 1,3-Dipolar cyclization reaction. The cyclopeptides which contained triazole skeleton showed significant anti-cancer activity against cancer cells with mutated ras oncogene such as A549, PC3 and C26 cells. This study clearly shows the importance of triazole skeleton in biological activity of the peptides. It might be possible to overcome the difficulties involved in making complex peptides by employing this elegant chemistry.

This review highlights different approaches for the synthesis of cyclopeptides containing heterocyclic skeletons such as triazole, imidazole, tetrazole, oxazole and thiazole.