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Wrocław, Poland

Olszewski T.K.,Apeiron Synthesis | Jaskolska D.E.,Apeiron Synthesis
Heteroatom Chemistry | Year: 2012

Copper and silver N-heterocyclic carbene (NHC) complexes were prepared through a simple, base-free protocol involving the decomposition of corresponding imidazol(in)ium-2-carboxylates under thermolytic conditions and a subsequent reaction of the in situ generated carbenes with copper(I) or silver(I) chloride, respectively. The desired NHC metal complexes were isolated with good yields after simple crystallization. © 2012 Wiley Periodicals, Inc.

Skowerski K.,Apeiron Synthesis | Biatecki J.,Apeiron Synthesis | Czarnocki S.J.,Apeiron Synthesis | Zukowska K.,Polish Academy of Sciences | Grela K.,University of Warsaw
Beilstein Journal of Organic Chemistry | Year: 2016

An ammonium-tagged ruthenium complex, 8, was deposited on several widely available commercial solid materials such as silica gel, alumina, cotton, filter paper, iron powder or palladium on carbon. The resulting catalysts were tested in toluene or ethyl acetate, and found to afford metathesis products in high yield and with extremely low ruthenium contamination. Depending on the support used, immobilised catalyst 8 shows also additional traits, such as the possibility of being magnetically separated or the use for metathesis and subsequent reduction of the obtained double bond in one pot. © 2016 Skowerski et al; licensee Beilstein-Institut.

Knapkiewicz P.,Wroclaw University of Technology | Skowerski K.,Apeiron Synthesis | Jaskolska D.E.,Apeiron Synthesis | Barbasiewicz M.,University of Warsaw | Olszewski T.K.,Apeiron Synthesis
Organic Process Research and Development | Year: 2012

Herein, we describe the use of continuous flow chemistry for selective, efficient and reproducible nitration of 2-isopropoxybenzaldehyde to produce the desired 2-isopropoxy-5-nitrobenzaldehyde, an important building block in the preparation of a ligand of nitro-substituted Hoveyda-Grubbs metathesis catalyst. Nitration was done with red fuming HNO 3, and this challenging and hazardous process was performed using a flow-through silicon-glass microreactor equipped with a set of temperature sensors, and with a productivity of 13 g/h, providing us with a reproducible chemical process amenable for production of sufficient quantities of 2-isopropoxy-5-nitrobenzaldehyde for ongoing large-scale synthesis of nitro-substituted Hoveyda-Grubbs metathesis catalyst. © 2012 American Chemical Society.

Szczepaniak G.,University of Warsaw | Urbaniak K.,Apeiron Synthesis | Wierzbicka C.,Apeiron Synthesis | Kosinski K.,University of Warsaw | And 2 more authors.
ChemSusChem | Year: 2015

Three isocyanides containing a tertiary nitrogen atom were investigated for use as small-molecule ruthenium scavenging agents in the workup of olefin metathesis reactions. The proposed compounds are odorless, easy to obtain, and highly effective in removing metal residues, sometimes bringing the metal content below 0.0015 ppm. The most successful of the tested compounds, II, performs very well, even with challenging polar products. The performance of these scavengers is compared and contrasted with other known techniques, such as silica gel filtration and the use of self-scavenging catalysts. As a result, a new hybrid purification method is devised, which gives better results than using either a self-scavenging catalyst or a scavenger alone. Additionally, isocyanide II is shown to be a deactivating (reaction quenching) agent for olefin metathesis and superior to ethyl vinyl ether. © 2015 The Authors.

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