Reducing disaccharides and their 1,2-dicarbonyl intermediates as building blocks for nitrogen heterocycles

Abstract

The existential importance of a sustainable economy necessitates the utilisation of plant based renewable resources such as lignin and carbohydrates. Carbohydrate utilization as industrial raw materials requires low environmental impact conversions from sugars to high value products. Here we present the conversion of reducing disaccharides into industrially relevant heterocycles of the quinoxaline-, 1,2,4-triazine-, pyrazineand pyrazolo[3,4-b]quinoxaline-type. Heterocycle formation was facilitated by chemical conversion of reducing sugars into 1,2-dicarbonyl intermediates and their subsequent cyclization with nitrogen bisnucleophiles. A range of disaccharides was converted into quinoxalines carrying a diverse glycosylation pattern on the polyhydroxy alkyl side chain. All transformations were performed without the need of protecting group chemistry.

Synthesis and Antioxidant Activity Evaluation of Some Novel Aminocarbonitrile Derivatives Incorporating Carbohydrate Moieties

“…Moreover, carbohydrates have been used as reagent in organic synthesis to obtain new organic molecules containing carbohydrate fragments. Along this line, some of the heterocycles, including pyrazines, imidazoles, quinoxalines, pyrazolo­[3,4- b ]-quinoxalines, and benzimidazoles, have been synthesized using carbohydrates as reagent. − For example, there are some reports on the use of carbohydrate-based heterocycles as corrosion inhibitor of mild steels. , …”

Cycloamination strategies for renewable N-heterocycles

“…316 In a similar way, reduced sugars proceeding via 1,2-dicarbonyl intermediates by reaction with different nitrogen sources furnish the quinoxaline, 1,2,4-triazine, pyrazine and pyrazolo [3,4-b]quinoxaline skeletons. 317 In these strategies, protection group chemistry is not needed for the in situ multi-step transformations. With respect to the synthesis of azaheterocycles via multicomponent reactions, selection of subcomponents allows control of the product distributions.…”