The reactions of β‐azolylenamines 1 with sulfonyl azides 2 in acetonitrile furnished 1H‐4‐(azol‐5‐yl)‐1,2,3‐triazoles 3 in yields of 52–93 %. β‐Benzoylenaminones and β‐nitroenamine of type 1 also reacted with tosyl azide to form the same type of products 3, proving the generality and efficiency of the method for the synthesis of N‐unsubstituted 1,2,3‐triazoles. On the other hand, the reactions of 3‐(1‐aryl‐1,2,3‐triazol‐5‐yl)enamines with tosyl azide in the absence of a solvent afforded a mixture of (E)‐1‐dimethylamino‐2‐tosylaminoethenes 5 and N,N‐dimethyl‐N′‐tosylformamidine 6 in yields of 40–50 and 20 %, respectively. The formation of a variety of compounds from the reactions of enamines 1 with sulfonyl azides 2 is rationalized by the various possible transformations of the intermediate 5‐dimethylamino‐1,2,3‐triazolines 7.

We herein demonstrate a new approach for the synthesis of 2,4‐disubstituted pyrroles by [3+2] cycloaddition reaction of isocyanides to the activated double bond of various enamines and enaminones. This process paved the way for the synthesis a series of 2,4‐disubstituted pyrroles, which are known to be intermediates in the synthesis of biologically active compounds, in good to excellent yields from simple and commercially available starting materials. The process is carried out efficiently using a strong base, tBuOK, at low temperatures (0 °C). The described method is simple, proceeds in one step, does not require additional catalysts and hence, has a wide scope.

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This review is devoted to the recent advances in the chemistry of methylene isocyanides with C=C, C≡C, C=O, and C=N bonds. In this paper, we show a variety of [3+2] cycloaddition reactions for isocyanides, carried out both under catalytic and non‐catalytic conditions. In addition, we also focused on diastereo‐ and enantioselectivity data.

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