In recent years, N-tosylhydrazones have been increasingly used in metal-free and transition metal-catalyzed coupling reactions instead of the unstable diazo compounds [1, 2]. Carbohydrate coupling reactions are poorly known, and couplings with sugar tosylhydrazones represent a completely new area of carbohydrate chemistry. Coupling reactions of N-tosylhydrazones can be applied for the formation of carbon-carbon and carbon-heteroatom bonds, as well. Examples of C-N couplings with amines and N-heterocycles can also be found in the literature [3, 4]. Under these preliminaries we started a systematic study about 4 years ago to investigate the applicability of anhydro-aldose-tosylhydrazones 1  in coupling reactions. In this project C-O  and C-S  bonds were successfully formed under metal-free conditions and C-C bonds [8, 9] in Pd-catalyzed reactions. As a next step we started to investigate the possibility of C-N bond formation by coupling of 1 with amines and N-heterocycles. Reactions of 1 with amines were not successful, but the metal-free reactions with N-heterocycles provided the N-(β-D-glycopyranosyl)methyl-heterocycles 2 (See Figure 1). In this presentation we disclose our results.
The research was supported by the EU and co-financed by the European Regional Development Fund under the project GINOP-2.3.2-15-2016-00008, and by the National Research, Development and Innovation Office under the project FK128766.
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