Thio-Ugi reactions are described as an excellent synthetic tool for the synthesis of sterically highly hindered endothiopeptides. S-Methylation and subsequent amidine formation can be carried out in an inter- as well as in an intramolecular fashion. The intramolecular approach allows the synthesis of the bottromycin ring system in a straightforward manner.

The 5-amino-(cyanoformimidoyl)-1H-imidazole has been prepared from amidine by treatment with barium hydroxide in ethanol. 2-(4-Isopropylbenzyl)-6-carbamoyl-1, 2-dihydropurine was obtained from 5-amino-4-(cyanoformimidoyl)-1H-imidazole and isopropylbenzaldehyde in dry methanol. All compounds have been fully characterized by spectroscopic data.

Borsook and Dubnoff (1, 2) and Bloch and Schoenheimer (3) have demonstrated that the amidine moiety of arginine is the precursor of the corresponding group of glycocyamine; in mammals this reaction is carried out primarily in the kidney. Fuld (4) has recently observed that the arginine-glycine transamidination reaction is reversible. By means of group transfer the high chemical potential of the...

silica sulfuric acid as an efficient and reusable heterogeneous catalyst has been used for the preparation of amidines 2 from formimidate 1 by reaction with aromatic amines at room temperature in good to excellent yields. imidate was prepared by treatment of equimolar quantities of triethyl orthoformate and diaminomaleonitrile in refluxing dioxane. all the compounds were characterized fully by ...

the aryl-(z)-n-[2-amino-1,2-dicyanovinyl]formamidine 2 cyclize in solvent-free conditions and in the presence of a base to give a 5-amino-1-aryl-4-cyanoimidazoles 3. silica sulfuric acid as an efficient and reusable heterogeneous catalyst has been used for the preparation of amidines 2 from formimidate 1 through reaction with aromatic amines at room temperature and in good to excellent yields. ...

This communication demonstrates the preparation, isolation, and full characterization of superelectrophilic salts based on amidine dications in organic solvent, as their triflate salts. These dications are highly activated toward regiospecific reaction with hydrogen gas under mild conditions in the presence of a metal catalyst (Pd/C), mimicking the behavior of the natural substrate, N(5),N(10)-...