Iridium-catalysed condensation of alcohols and amines as a method for aminosugar synthesis

Abstract

Primary carbohydrate amines at primary and secondary carbons are alkylated by alcohols in the presence of [Cp*IrCl(2)](2). When primary carbohydrate alcohols are used as the coupling partners and in the presence of Cs(2)CO(3), amine-linked pseudodisaccharides are obtained. Secondary carbohydrate alcohols are unaffected under these conditions, which allows regioselective reactions.

Advances in One-Pot Synthesis through Borrowing Hydrogen Catalysis

“…173 Other interesting applications of Ir-based catalyst led to the N-alkylation of carbohydrate alcohols leading to N-substituted aminosugars with potential applications in the biochemical and pharmaceutical fields. 174 Similarly, Fujita et al reported that [Cp*IrCl 2 ] 2 efficiently catalyzed the coupling between different amines and monoalcohols, or even vicinal diols for the synthesis of Nheterocycles, 175,176 whereas a related Ir compound [Cp*IrI 2 ] 2 was also successfully applied in this reaction in a more benign aqueous media and without requiring the use of a base. 159 Besides, the synthesis of N-heterocycles through an intramolecular reaction of amines has also been described to take place in the presence of closely related Ir-based catalysts.…”

Mechanistic studies on the N-alkylation of amines with alcohols catalysed by iridium(i) complexes with functionalised N-heterocyclic carbene ligands

“…[11] In fact, [Cp*IrCl 2 ] 2 has been applied for the coupling amines and alcohols in the absence of base, [9f,12] the N-heterocyclization of primary amines with diols, [13] or even the N-alkylation of carbohydrate-based amines. [14] N-Heterocyclic carbenes (NHCs) have attracted considerable attention as ligands for the design of transitionmetal catalysts. The distinct stereoelectronic properties of NHCs make them efficient ancillary ligands not only for the stabilization of reactive intermediates but also for the improvement of the catalytic activity.…”

Design and synthesis of glycomimetics: Recent advances

“…Additionally, glycosylation is actively employed as a mean of improving the physicochemical properties and the membrane permeability of peptide drugs . N ‐glycosidic linkages created between a sugar and an aglycon (often a peptide) are well described in the literature, while synthetic methods for the synthesis of N ‐glycosidic bonds between two sugar units remain rare . In nature, N ‐linked glycosylation of peptides occurs through the amine group of an asparagine residue, resulting in the formation of an amide bond with a β‐linkage to the sugar moiety.…”