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Herein, we report a new transition‐metal‐free robust and cost‐effective method for synthesis of 1,2‐disubstituted indoles from easily available unactivated (i.e. without EWG, PPh3 or SiR3 groups) tertiary amides. Scope of synthetic applicability of the presented protocol was shown on 23 examples of 1,2‐disubstituted indoles with different substitution patterns obtained in good to excellent yields. The reported method turned out to be especially effective for synthesis of N‐arylated 2‐CF3‐indoles. Moreover, this approach can be performed in a one‐pot two‐step manner directly from commercially available secondary amines. Mechanistic studies showed that acyl transfer might be an important step in the course of the reaction. Viability of the presented approach for benzofurans and benzothiophenes synthesis was also discussed. [ABSTRACT FROM AUTHOR]

The chemical factors are tending to be the usual way to control the reaction selectivity. However, this approach is inapplicable in cases of compounds with two or more functional groups of almost the same or equal reactivity. On these occasions considering the reaction bulk physical properties can be much more beneficial. In the present work we studied one of these complicated cases, namely, the CuAAC reaction of symmetrical diazides or diynes in equimolar amounts, and developed two approaches to solve the selectivity problem between mono‐ and diaddition. Single cycloaddition in the CuAAC reaction of symmetric diazides or diynes can be achieved by: 1) precipitation of the monoaddition product, 1,2,3‐triazole, from nonpolar solvent – heptane; 2) the reaction halt after formation of monoaddition product due to increase of the viscosity in solvent‐free procedure. Thus, two new "green" one‐step methods of alkynyl‐ or azido‐functionalized 1,2,3‐triazoles synthesis were devised. Their utility was shown on 17 examples of good to excellent yields. [ABSTRACT FROM AUTHOR]

A highly efficient and environmentally benign protocol for copper‐catalyzed alkyne–azide cycloaddition (CuAAC) in industrially important alkane solvents was developed. New copper(I) complexes bearing NHC ligands decorated with bulky hexafluoroisopropylalkoxy group [(CF3)2(OR)C‐] were first introduced for the process. The complex with isopentyl group [(CF3)2(OiAm)C‐] exhibited the best catalytic activity in the reactions of diversely substituted alkyne and azide substrates in alkane solvents, such as hexane, heptane and cyclohexane. The new CuAAC protocol is easily scalable, synthetically robust, and reproducible; it utilizes low catalyst loadings and enables simple isolation of pure products free from any contaminants including residue of the catalyst and starting materials. A highly efficient and environmentally benign protocol for copper‐catalyzed alkyne–azide cycloaddition (CuAAC) in industrially important alkane solvents was developed. New (NHCF)CuI complex decorated with bulky group [(CF3)2(OiAm)C–] exhibited the best catalytic activity in the reactions of diversely substituted alkyne and azide substrates in alkane solvents. [ABSTRACT FROM AUTHOR]