Multicomponent diversity oriented synthesis of multivalent glycomimetics containing hexafluorovaline

Sugars in Multicomponent Reactions: A Toolbox for Diversity-Oriented Synthesis

“…In 2015, Volonterio and co-workers 73 carried out the synthesis of multivalent glycomimetics of potent biological applications consisting of hexafluorovaline (hfVal) 211 – 214 via a one-pot multicomponent sequential reaction of N -glycosylcarbodiimides, N -glycosyl- N ′- tert -butylcarbodiimides, and N , N ′-diglycosylcarbodiimides 207 with 4,4,4-trifluoro-3-(trifluoromethyl)crotonic acid ( 209 ) in the presence or absence of nitrogen nucleophiles, such as glycosyl amines 208 and α-amino esters or peptides 210 in good yields (up to 83%) (Scheme 55 ). This synthetic methodology was also utilized for the synthesis of a neomycin-hexafluorovaline-sugar which is of potent biological importance.…”

Recent Advances in the Synthesis of Hydantoins: The State of the Art of a Valuable Scaffold

“…Double substitution of hydantoins can as well be obtained with the use of carbodiimides. Their reaction with α,β-unsaturated carboxylic acids or α-bromoaryl acetic acids (Scheme ) enabled Volonterio et al to prepare a large variety of 1,3,5-trisubstituted hydantoins. − The preparation of unsymmetrical carbodiimides widened the scope of possible structures, incorporating carbohydrates − or glycosylamines as substituents of the hydantoins. However, when α-azido esters were used as starting material with various isocyanates, the authors observed that the main product of the reaction was not the expected carbodiimide but the N- carbamoyl-hydantoin obtained by the reaction of two equivalents of isocyanate on the α-azido esters .…”

Multicomponent Domino Synthesis and Antibacterial Activity of Neomycin–Sugar Conjugates

“…32 The complete regioselectivity was likely achieved because the less sterically hindered primary N-substituent on the carbodiimide intermediate is much more reactive than the tertiary tert-butyl N′-substituent in the intramolecular aza-Michael step (see Scheme 1). [26][27][28][29][30][31] Encouraged by this result, we went on to use several appropriately protected glycosyl azides such as N-acetylglucosamine 1b, mannose 1c, and disaccharide maltose 1d. In all cases, the MC process worked well giving rise to the re- A. Sganappa et al…”

“…Recently, we have introduced a regiospecific MC domino process, which is efficiently executed under very mild conditions and utilizes easily accessible components such as glycosyl azides, iso(thio)cyanates, fumaric acid monoesters, and amines (Scheme 1). [26][27][28][29][30][31] Thus, glycosyl azides A react with tert-butyl isocyanate (B) in the presence of Ph 3 P (Staudinger reaction followed by aza-Wittig reaction) giving rise to the formation of carbodiimides C. The reaction can be easily followed by TLC and the resulting carbodiimide used in situ. Once carbodiimide C is formed, the temperature is lowered to 0 °C and 2,4,6trimethylpyridine (TMP), amine E, then fumaric acid monoester D are added in this sequence.…”