Tomasz K. Olszewski

An attempt to provide an environmentally friendly solvent selection guide for olefin metathesis

A range of environmentally conservative solvents was evaluated for application in olefin metathesis. Different commercially available and most frequently applied ruthenium catalysts were employed. The data obtained can be used as a guide to facilitate replacement of environmentally detrimental chlorinated or aromatic solvents with greener reaction media in order to make applications of olefin metathesis in both industry and academia more environmentally benign and sustainable processes.

Biosourced Polymetallic Catalysts: An Efficient Means To Synthesize Underexploited Platform Molecules from Carbohydrates

Polymetallic hyperaccumulating plants growing on wastes from former mining activity were used as the starting material in the preparation of novel plant-based Lewis acid catalysts. The preparation of biosourced Lewis acid catalysts is a new way to make use of mining wastes. These catalysts were characterized by X-ray fluorescence, X-ray diffraction, inductively coupled plasma mass spectrometry, and direct infusion electrospray ionization mass spectrometry. These analyses revealed a complex composition of metal species, present mainly as polymetallic chlorides. The catalysts proved to be efficient and recyclable in a solid-state version of the Garcia Gonzalez reaction, which has been underexploited until now in efforts to use carbohydrates from biomass. This methodology was extended to various carbohydrates to obtain the corresponding polyhydroxyalkyl furans in 38-98% yield. These plant-based catalysts may be a better alternative to classical Lewis acid catalysts that were previously used for the Garcia Gonzalez reaction, such as ZnCl2 , FeCl3 , and CeCl3 , which are often unrecyclable, require aqueous treatments, or rely on metals, the current known reserves of which will be consumed in the coming decades. Moreover, the plant-based catalysts allowed novel control of the Garcia Gonzalez reaction, as two different products were obtained depending on the reaction conditions.

Adsorbed States of Phosphonate Derivatives of N-Heterocyclic Aromatic Compounds, Imidazole, Thiazole, and Pyridine on Colloidal Silver: Comparison with a Silver Electrode

Here, we report a systematic surface-enhanced Raman spectroscopy (SERS) study of the structures of phosphonate derivatives of the N-heterocyclic aromatic compounds imidazole (ImMeP ([hydroxy(1H-imidazol-5-yl)methyl]phosphonic acid) and (ImMe)(2)P (bis[hydroxy-(1H-imidazol-4-yl)-methyl]phosphinic acid)), thiazole (BAThMeP (butylaminothiazol-2-yl-methyl)phosphonic acid) and BzAThMeP (benzylaminothiazol-2-yl-methyl)phosphonic acid)), and pyridine ((PyMe)(2)P (bis[(hydroxypyridin-3-yl-methyl)]phosphinic acid)) adsorbed on nanometer-sized colloidal particles. We compared these structures to those on a roughened silver electrode surface to determine the relationship between the adsorption strength and the geometry. For example, we showed that all of these biomolecules interact with the colloidal surface through aromatic rings. However, for BzAThMeP, a preferential interaction between the benzene ring and the colloidal silver surface is observed more so than that between the thiazole ring and this substrate. The PC(OH)C fragment does not take part in the adsorption process, and the phosphonate moiety of ImMeP and (ImMe)(2)P, being removed from the surface, only assists in this process.

Aminophosphinic acids in a pyridine series : Cleavage of pyridine-2- and pyridine-4-methyl(amino)phosphinic acids in acidic solutions

The synthesis of a series of new pyridine aminomethylphosphinic acids is described. These compounds were obtained in the reaction of the corresponding pyridine aldehydes with primary amines and with ethyl phenylphosphinate, or methylphosphinate, in the presence of bromotrimethylsilane. In aqueous, strong acid solutions, pyridine aminophosphinic acids were split, forming the phenyl-, or methylphosphonic, acid and the corresponding secondary pyridyl-alkylamines. The kinetics of some observed cleavages were measured, and a mechanism of the cleavage has been proposed.

Ullmann reaction through ecocatalysis: insights from bioresource and synthetic potential

We report the elaboration of novel bio-sourced ecocatalysts for Ullmann coupling reaction. Ecocatalysis is based on the recycling of metals issued from phytoremediation or rehabilitation, and an innovative chemical valorization of the subsequent biomass in the field of catalysis. Here, we describe the efficient copper accumulation by plants via phytoextraction and rhizofiltration. These phytotechnologies were revisited to demonstrate a novel potential of these natural resources for the Green Chemistry. Taking advantage of the remarkable ability of the selected plants to accumulate Cu(II) species into their roots or leaves, these latter can be directly used for the preparation of ecocatalysts, called Eco-Cu ®. The formed Eco-Cu ® catalysts are thoroughly characterized via ICP-MS, IR study of pyridine sorption/desorption, TEM, XRD, SM and model reactions, in order to elucidate the chemical composition and catalytic activity of these new materials. Significant differences of properties and activities were observed between Eco-Cu ® and conventional Cu catalysts. Eco-Cu ® appear as highly active catalysts in Ullmann coupling reactions with lower Cu quantity compared to known copper catalysts.

Raman, Surface-Enhanced Raman, and Density Functional Theory Characterization of (Diphenylphosphoryl)(pyridin-2-, -3-, and -4-yl)methanol

This work presents near-infrared Raman spectroscopy (FT-RS) and surface-enhanced Raman scattering (SERS) studies of three pyridine-α-hydroxymethyl biphenyl phosphine oxide isomers: (diphenylphosphoryl)(pyridin-2-yl)methanol (α-Py), (diphenylphosphoryl)(pyridin-3-yl)methanol (β-Py), and (diphenylphosphoryl)(pyridin-4-yl)methanol (γ-Py) adsorbed onto colloidal and roughened in oxidation-reduction cycles silver surfaces. The molecular geometries in the equilibrium state and vibrational frequencies were calculated by density functional theory (DFT) at the B3LYP 6-311G(df,p) level of theory. The results imply that the most stable structure of the investigated molecules is a dimer created by two intermolecular hydrogen bonds between the H atom of the α-hydroxyl group (in up (HOU) or down (HOD) stereo bonds position) and the O atom of tertiary phosphine oxide (═O) of the two monomers. Comparison the FT-RS spectra with the respective SERS spectra allowed us to predict the orientation of the hydroxyphosphonate derivatives of pyridine that depends upon both the position of the substituent relative to the ring N atom (in α-, β-, and γ-position, respectively) and the type of silver substrate.

Ecocatalysis: A New Approach Toward Bioeconomy

Reconquest of biodiversity, remediation of anthropic and degraded sites, prevention of environmental health hazards, eco-innovation, green industry … Current ambitions are closely related to an interdisciplinary approach to scientific ecology able to participate in expected industrial renewal. In this chapter we will show how the unusual combination of phytotechnologies adapted to pollution and ecological rehabilitation of polluted sites, and enhancement of these processes through innovative green chemistry, can contribute to the current development of scientific, economic, and environmental priorities of eco-innovation, biomass conversion, and the transition from fossil resources to renewables.

Exploring the Isomer Dependent SERS Spectra of (diphenylphosphoryl)(pyridin-2, -3, and -4-yl)methanol Adsorbed on Gold Nanocolloids

The surface-enhanced Raman scattering (SERS) spectra of three aminophosphonate derivatives of pyridine: (diphenylphosphoryl)(pyridin-2-yl)methanol (-Pyr), (diphenylphosphoryl)(pyridin-3-yl)methanol (-Pyr), and (diphenylphosphoryl)(pyridin-4-yl)methanol (-Pyr) were measured after immobilization onto colloidal gold surface. Changes in the wavenumber, broadness, and enhancement between the corresponding Raman and SERS bands allowed to deduce orientation of the -, -, and -isomers (-, -, and -refer to the position of the substituent relative to the ring nitrogen atom) of aminophosphonate derivatives of pyridine on the gold surface. Briefly, it was demonstrated that the -Pyr and -Pyr show the same mode of adsorption, whereas the adsorption process of the -Pyr isomer differs in this regard that pyridine assists in the interaction with the gold surface.

Application of tris(trimethylsilyl) phosphite as convenient phosphorus nucleophile in the direct synthesis of tetrasubstituted α-aminophosphonic acids from ketimines

The condensation of tris(trimethylsilyl) phosphite with various ketimines leads directly to tetrasubstituted αaminophosphonic acids. The presented reaction proceeds readily at room temperature and provides labile silylated esters of tetrasubstituted α-aminophosphonic acids, as non-isolable reaction intermediates. Subsequent methanolysis of the latter provides the desired α-aminophosphonic acids bearing an fully substituted α-carbon in good overall yields as crystalline non-hygroscopic solids after simple recrystallization from a methanol-acetone mixture.nordstom