Iron‐Catalyzed Intramolecular Arene C(sp²)−H Amidations under Mechanochemical Conditions

Abstract

In a ball mill, FeBr3‐catalyzed intramolecular amidations lead to 3,4‐dihydro‐2(1H)‐quinolinones in good to almost quantitative yields. The reactions do not require a solvent and are easy to perform. No additional ligand is needed for the iron catalyst. Both 4‐substituted aryl and β‐substituted dioxazolones provide products with high selectivity. Mechanistically, an electrophilic spirocyclization followed by C−C migration explains the formation of rearranged products.

Divergent synthesis of nitrogen heterocyclesviaH2O-mediated hydride transfer reactions

“…1), but straightforward methods to access them are very scarce. 12 In order to develop a direct, efficient, and green method to construct this unit, acyclic amine-substituted benzaldehydes and Meldrum's acid were investigated to examine the reaction activity in this green system. To our delight, the expected transformation took place and the corresponding product 3a was obtained in 93% yield via the cascade Knoevenagel condensation/[1,5]-hydride transfer/ N -dealkylation/ N -acylation/decarboxylation process.…”

Spiers Memorial Lecture: Mechanochemistry, tribochemistry, mechanical alloying – retrospect, achievements and challenges

“…Steel can act as a catalyst because its main component is iron, and this can be expected. 273,432 At the same time, different types of steel contain different transition metals as dopants, which may act as catalysts of the mechanochemical transformations, 38,287 yet remain unknown even to the experimentalists themselves, and thus not documented.…”

Electromagnetic mill promoted mechanochemical palladium-catalyzed solid state cyanation of aryl bromides using non-toxic K4[Fe(CN)6]

“…Some elegant works on the construction of C-C, C-O, C-N bonds, etc. have been reported by Ito, [44][45][46][47][48][49][50] Bolm, [51][52][53][54][55][56] Wang, [57][58][59][60] Su, 61 Friščić [62][63][64] and other groups, [65][66][67][68] respectively. On the other hand, an electromagnetic mill (EMM) is a novel grinding device and uses small ferromagnetic particles as the grinding media in a rotating electromagnetic field.…”