based on a photocatalyzed oxidative decarboxylation of oxamic acids is described. The reaction includes in situ generation of an isocyanate from the oxamic acid, using an organic dye as a photocatalyst, a hypervalent iodine reagent as an oxidant and a light source, which trigger the free-radical decarboxylation. This protocol successfully avoids the isolation, purification and storage of carcinogenic
Preparation of N,N′-bis(aryl)guanidines from electron deficient amines via masked carbodiimides
作者:Mark R. Barvian、H.D. Hollis Showalter、Annette M. Doherty
DOI:10.1016/s0040-4039(97)01598-0
日期:1997.9
Preparation of N,N′-bis(aryl)guanidines by alkylation of electron deficient amines with trityl protected carbodiimides is described. Also reported is a method for the dehydration of N-trityl-N′-aryl ureas to the corresponding carbodiimides using the Burgess reagent.