Sugar carbodiimides

Sugar isothiocyanates 75 are also converted with azides and Iriphenylphosphorous into sugar carbodiimides 76." ... 

Glycolipids are similarly synthesized using DDC and HOBL Bicyclic azasugar gly-comimetics related to castanospermin are prepared from sugar carbodiimides via aminoox-azoline derivatives. ... 

Sugar carbodiimides are key intermediates in the synthesis of some glycoconjugates. ... 

J. M. Garcia Fernandez, C. O. Mellet, V. M. Diaz Perez, J. Fuentes, J. Kovacs, and I. Pinter, Aza-Wittig reaction of sugar isothiocyanates and sugar iminophosphoranes An easy entry to unsymmetrical sugar carbodiimides, Tetrahedron Lett., 38 (1997) 4161-4164. 

Reduction of uronic acids Uronic acids (UA) were converted to the corresponding neutral sugars (NS) by carbodiimide activation of the carboxyl groups followed by a reduction with NaBD4 according to the method of Kim and Carpita [5]. In order to achieve a complete reduction of the uronic acids the procedure was repeated once. 

Figure 1.95 Carboxylate-containing sugars may be modified with diamines using a carbodiimide-mediated reaction to create available amine groups for subsequent conjugation.

Thioureas are most commonly prepared from reaction of isothiocyanates with amines. Also there are some reports on reactions of anime or carbodiimides with several thionating reagents. AA -Disubstituted thioureas bearing double NH groups have been developed as sensors, and as catalysts because of their hydrogen bonding ability. A,A -Disubstituted thiourea-linked sugar chains have been prepared by the reaction of isothiocyanate with amine. 

Treatment of sugar-derived carbodiimides with dry hydrogen sulfide (H2S) in the presence of activated silica gel affords the sugar-derived thioureas (Scheme 46).127... 

Reducing sugars on treatment with dicyclohexyl carbodiimide (DCC) undergo rearrangement to form a mixture... 

Photochemical a-addition of a nitrene to 1-isocyano sugars leads to the carbodiimide which adds water yielding glycosylurea or malonic acid to form potential glycosyl-barbiturate synthons [57] (Scheme 29). 

Instead of the second equivalent of the primary amine, triethylamine can also be used. For example, reaction of the sugar carbonimidoyl dichloride 124 with cyclohexylamine and triethylamine gives a quantitative yield of the carbodiimide 125. ... 

The reaction of carbodiimides with water to give the corresponding N,N -disubstituted ureas 433 is catalyzed by acids and bases. For example, acetic acid is an effective catalyst in the formation of ureas from sugar derived carbodiimides. ... 

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