Quinoline and acridine derivatives have been prepared using a functionalized imidazolium salt as heterogeneous catalyst. Different ketones have been coupled with 2‐aminobenzaldehydes and 2‐aminoaryl ketones under solvent‐free conditions, employing 1,3‐bis(carboxymethyl)‐imidazolium chloride as a catalyst. The protocol is simple and effective for the synthesis of a variety of nitrogen containing heterocycles (> 35 examples) with moderate to excellent yields (up to 96 %), being possible to perform the reaction in preparative scale. Additionally, 3‐acetylquinolines have been transformed, under solvent‐free conditions, into quinolyl chalcone derivatives by means of the same catalyst. Thus, the catalytic system mediates both reactions effectively in a tandem procedure. Furthermore, the catalyst is easily separated from the reaction mixture and can be reused without loss of activity (up to 8 cycles) which remarks its sturdiness. The E‐factors are in the range of 14–23, both for the formation of quinolines and for the tandem reaction, which demonstrates the sustainability of the protocols described.

Amino amides, which are readily accessible from amino acids, were used in the preparation of both monoamido and diamido functionalized imidazolium salts in very straightforward protocols. Different catalytic systems formed with palladium(II) acetate and acyl functionalized imidazolium salts were tested in the Matsuda‐Heck reaction. The comparative study revealed that the presence of one carbamoyl moiety in the N‐heterocyclic carbene precursor is more beneficial during the catalytic process. Thus, better activity was observed with the catalytic system formed using 3‐benzyl‐1‐(N‐phenylcarbamoylmethyl)imidazolium chloride in a 1:1 metal/ligand ratio. Moreover, this fact was evidenced by means of UV/vis studies.

The oxidative cleavage of indoles (Witkop oxidation) involving the use of H2O2 or urea hydrogen peroxide in combination with a polar solvent has been described. Among these solvents, 1,1,1,3,3,3‐hexafluoroisopropanol (HFIP) stands out as the one affording the corresponding 2‐ketoacetanilides generally in higher yields The protocol described has also enabled the oxidation of different pyrroles and furans derivatives. Furthermore, the procedure was implemented in a larger‐scale and HFIP was distilled from the reaction mixture and reused (up to 4 cycles) without a significant detriment in the reaction outcome, which remarks its sustainability and applicability.

The straightforward synthesis of N,N-disubstituted formamides using 1,1,1,3,3,3hexafluoroispropanol (HFIP) and H 2 O 2 combination is described. The unique features of HFIP allowed the utilization of a green oxidant such as H 2 O 2 and the products, arising from an oxidation-rearrangement sequence, were obtained in good to high yields under smooth reaction conditions. INTRODUCTION

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