New Members of the Cinchona Alkaloids Family: Assembly of the Triazole Heterocycle at the 6′ Position

Abstract

The substance class of the well-known Cinchona alkaloids is widened by 6′-Amino-cinchonine and 6′-Amino-cinchonidine, novel compounds which incorporate a primary amino function in the quinolinic ring system. These key intermediates open the field for a range of fruitful chemistry. Here is described a short and direct pathway for the synthesis of triazole containing derivatives of the above-mentioned substances using the [3 + 2] Huisgen cycloaddition. For this purpose, the amines were first converted into the corresponding azides. Based on this, non-substituted and silyl-protected triazoles were synthesized as examples. Furthermore, didehydrated derivatives of quincorine and quincoridine were used as addition partners, resulting in compounds that carry the quinuclidine ring of the cinchona alkaloids at both ends. Some of these compounds were examined radiographically to investigate the position of the quinuclidine ring to the triazole. The solid-state structures of compounds 10, 11 and 28 were determined by X-ray diffraction analyses.

Huisgen 3 + n Dipolar Cycloaddition Reactions: An Accessible and Useful Tool in Modern Organic and Heterocycle Synthesis

“…This Special Issue (SI) focuses on Huisgen 3 + n dipolar cycloaddition reactions as a useful and powerful tool in the synthesis and chemistry of new heterocycle derivatives. The SI provides an update of relevant and important original contributions [1,2,[4][5][6][7][8] and reviews [3,9] pertaining to these reactions, which have brought about significant advances in the development of the field of heterocycle derivatives.…”

“…Another original contribution to the SI has focused on obtaining new synthetic members of the Cinchona alkaloid family containing triazole derivatives by using the [3 + 2] Huisgen cycloaddition of azide to dipolarophile with a triple bond [7]. The triazole moiety was synthetised from the corresponding azido-cinchonine (1,3-dipol) with trimethylsilylacetylene (dipolarophile).…”