An efficient heterogeneous catalytic method for the N-arylation of pyrrole and other N-heterocycles

Palladium(II) on 4 Å Molecular Sieves: A Simple and Reusable Catalyst for the Preparation of Ynones

“…In heterogeneous catalytic methods Pd(II) compounds may also have good catalytic activity, as shown in our preliminary experiments. A similar effect has already been observed during the arylation of pyrrole with aryl halides in the presence of 4A-supported copper catalysts [56]. A Pd 0 /4A catalyst is more sensitive, requires an inert atmosphere and it has pyrophoric properties, thus Pd 2+ /4A can be used easier.…”

Heterogeneous copper-catalyzed coupling of amines: a possible way for the preparation of imines

“…/4A), which has successfully been applied earlier in the preparation of propargylamines [32], as well as in the N-arylation of different heterocycles [33]. We found that benzylamine at 120°C, without solvent, under ambient atmosphere, in the presence of Cu 2?…”

“…Cu 0 /4A was prepared by the reduction of Cu 2? /4A as described in [33]; Cu 2? /4A (5 g) was reduced with 6.13 cm 3 hydrazine hydrate (80 % aqueous solution) in 50 cm 3 ethanol for 3 h at room temperature.…”

The Application of 4Å Molecular Sieves in Organic Chemical Syntheses: An Overview

“…Previously we successfully applied Cu 0 and Cu 2+ on MS 4A as efficient catalysts for the arylation of pyrrole (108) and other N-heterocycles with aryl iodides or aryl bromides 107 in the presence of Cs 2 CO 3 as base in pyrrole (or DMF in case of other heterocycles) (Scheme 34). 60 Without the application of the base or the catalyst, no reaction occurred. We examined different aryl halides 107 in the arylation reaction, and the desired products were usually formed with high yield and good to excellent conversion in the presence of Cu 0 /MS 4A under ambient atmosphere.…”