An efficient direct approach to triazole-fused sultams has been developed. The key step of the proposed strategy is base-mediated cyclization of sulfonamide-tethered 5-iodo-1,2,3-triazoles which are readily available via an improved protocol for Cu-catalyzed 1,3-dipolar cycloaddition. The annulation of the sultam fragment to the triazole ring proceeds smoothly under transition-metal-free conditions in the presence of Cs2CO3 in dioxane at 100 °C and affords fused heterocycles in high yields up to 99%. The favorability of an SNAr-like mechanism for the cyclization was supported by DFT calculations. The applicability of the developed procedure to modification of natural compounds was demonstrated by preparation of a deoxycholic acid derivative.

Base-mediated cyclization of (5-iodo-1,2,3-triazolyl)phenols was proposed as a new synthetic strategy for the in situ generation of diazoimines via electrocyclic ring opening of the fused heterocycle. Cu-catalyzed amination of the intermediate diazoalkanes was employed to develop an efficient cascade approach to functionalized benzoxazoles.

The copper‐catalyzed azide–alkyne cycloaddition reaction was used for the preparation of a series of bis‐ and tris‐3‐ and 24‐5β‐cholanetriazolyl derivatives of phosphorus acids, which contained anion‐binding triazolium sites and hydrophobic cholane residues. The influence of the location of the triazolium moiety (in 3α‐, 3β‐position) on fluoride‐ion complexation was investigated. The anion‐binding properties of tris(triazolium) ligands were studied for a series of inorganic and organic anions and high complexation constants were observed with fluoride, hydrosulfate, and benzoate anions.

Cu- and Pd-catalyzed arylation of aminocholanes has been described for the first time. While this Cu-catalyzed protocol provides high yields in reactions of aminocholanes with iodoarenes, Pd catalysis was found to be preferable for the reactions of aminocholanes with dichloroanthraquinones. UV–vis titration of bis(cholanylamino)anthraquinones with a series of cations demonstrated their high binding affinity to Cu2+, Al3+, and Cr3+.

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