difficulties in separation of the products and catalyst recycling make this methodology less
attractive from the industrial point of view.
In the past 10 years, several efficient immobilised palladium-catalysts were developed,
primarily for C-C coupling reactions [3]. At the same time, only a few examples have been
reported for the use of supported catalysts in aminocarbonylations [4]. Moreover, most of these
reactions were carried out under CO pressure that required the use of high pressure techniques.
Alkoxycarbonylation [5] and microwave induced aminocarbonylation of aryl iodides [6] as well
as the synthesis of N-substituted phthalimides [7] were performed in the presence of Pd/C under
5-9 bar CO pressure. A polymer supported palladium-N-heterocyclic carbene complex was shown
to be a recyclable catalyst in aminocarbonylations under 6.9 bar CO [8]. A palladium catalyst,
immobilised by a bidentate phosphine ligand grafted on Merrifield resin, was reported to convert
bromoarenes to amides at 4.8 bar CO [9]. Pd nanoparticles supported on a zeolitic imidazole
framework (ZIF-8) were described as an efficient heterogeneous catalyst for the
aminocarbonylation of bromoarenes in the presence of phosphines and iodoarenes under
phosphine-free conditions using a CO pressure of 4 bar [10].
The use of higher pressures (30-40 bar) usually led to selective double carbonylation leading
to α-ketoamides. A silica-supported polytitazane–palladium (Ti–N–Pd) complex [11], Pd/C used
3
together with PPh as ligand [12] or palladium-phosphine complexes grafted onto mesoporous
silica (SBA-15) [13] were proved to be active catalysts in such reactions.
In most cases, atmospheric aminocarbonylations were performed with catalysts obtained by
the immobilisation of special, bidentate ligands on solid supports. Cai’s group reported on the
application of palladium-catalysts with bidentate phosphine [14], arsine [15] and mixed sulphur-
phosphine ligands [16] as well as monodentate selenium ligands [17] grafted on silica [15-17] or
MCM-41 [14].
Recently, Seayad disclosed results on atmospheric pressure carbonylation of aryl iodides in
the presence of palladium nanoparticles supported on a metal-organic framework [18]. At the
same time, 2 bar CO pressure had to be used for an efficient recycling of the catalyst and long
reaction time, 24 h in most cases, was necessary with aromatic amines as nucleophiles. Moreover,
it was admitted that this catalyst needed special handling because MOF-5 was moisture-sensitive,
and structural changes occurred that negatively affected the catalytic performance [10]. The
synthesis of isoindole-1,3-diones by a carbonylative cyclisation reaction was reported by Bhanage
using PdCl
2
immobilised on a supported ionic liquid phase (SILP) [19].
In our group, heterogeneous palladium catalysts were prepared using a SILP with grafted
imidazolium-tetrafluoroborate moieties for the immobilisation of palladium [20]. Under pressure,
excellent yields of α-ketoamides, formed by double carbonylation, were obtained. At the same
time, under atmospheric conditions only low conversion of the aryl iodide was observed.
In this paper our results concerning carbonylation of aryl iodides with aromatic amines,
carried out in the presence of SILP palladium catalysts, are presented. It is shown that the outcome
Page 3 of 19