A novel regioselective synthesis of aryl-substituted pyrazolines and pyrazoles has been developed. Substituted phenylhydrazines react with 3-butynol in the presence of a catalytic amount of zinc triflate to give pyrazoline derivatives. The resulting products are easily oxidized in a one-pot procedure to the corresponding pyrazoles.

Indole click chemistry: The quest for better catalysts for the intermolecular hydrohydrazination to indoles leads to zinc salts. A simple one‐pot synthesis forms indoles from arylhydrazines and terminal alkynes. The pharmacologically relevant indole building blocks are selectively formed in the presence of zinc triflate (Zn(OTf)2) or ZnCl2 (see scheme).

Catalytic hydroaminations are one of the most sustainable C-N bond-forming processes as a result of 100% atom economy and the availability of substrates. Here, it is shown that the intermolecular hydroamination of terminal alkynes with anilines proceeds smoothly in the presence of catalytic amounts of zinc triflate, an easily available and inexpensive zinc salt. Amination and subsequent reduction with NaBH3CN gives a variety of secondary and tertiary amines in up to 99% yield and with over 99% Markovnikov regioselectivity. Moreover, difficult functional groups such as nitro and cyano substituents are tolerated by the homogeneous catalyst.

A transition-metal-free, simple and efficient one-pot method for the synthesis of indole-2,3-dicarboxylates and 2-arylindole-3-carboxylates is described. The corresponding products are obtained by a domino hydroamination/Fischer indole cyclization in good-to-excellent yields from easily

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