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The total area of agricultural land in Europe and Slovenia is constantly decreasing, causing the loss of a potential for food production and self-sufficiency capacity. In addition to limiting soil sealing, one of the main objectives of the EU Soil Strategy for 2030 involves recultivating degraded sites, which requires appropriate materials, in particular for fertile, top layers.Due to the complexity of the restoration process of agricultural land, the ability of the restored areas to provide full or any scope of ecosystem services as expected depends on several factors. What the opencast mines have in common is the removal of the top, fertile part of the soil in the exercising of mining rights. The availability of fertile soils with suitable properties is often one of the main limitations for appropriate recultivation. Whilst less fertile soil or even inert construction or industry residuals may be used to recultivate the lower layers, the top layers require using engineered soils with appropriate physical, biological and chemical properties. These properties depend on the purpose of the final use of sites. Apart from making sure that the engineered soils have appropriate physical, chemical and biological properties, it is also necessary that they do not contain excessive concentrations of potentially hazardous substances when it comes to agricultural use.The primary aim and objective is to develop technologies for producing fertile soils from inorganic and organic waste resulting from construction work or opencast mines and other industrial processes. The main categories of waste where the Slovenian recycling rate is lower than the EU rate are sewage sludge and non-hazardous construction and demolition waste. In this contribution, we are studying how to improve non-fertile soils with various additives of secondary origin to prepare fertile soil mixtures that enable a safe space greening or even food production.Acknowledgements: Project LIFE20 IPE/SI/000021 je co-financed by European Union.Keywords: agricultural landscape, land rehabilitation, recultivation, top soil

Pri poimenovanju in klasifikaciji tal se že vse od njenih začetkov soočamo z izzivi, ki izhajajo tako iz vpeljave tujih neznanih izrazov kot iz sprememb diagnostičnih meril in analitskih postopkov, s katerimi jih preverjamo. Pri prevajanju imen pedosistematskih enot Pedološke karte Slovenije (1 : 25.000) za namen mednarodnih publikacij in zemljevida tal Evrope, smo zasledili težave pri razumevanju akričnih tal. Akrična tla so v Pedološki karti opredeljena kot zelo kisla tla, z deležem bazičnih kationov na sorptivnem kompleksu tal manj kot 35% in sodijo med izprana tla. Merilo klasifikacije WRB za akričnost (qualifier acric) je majhna kationska izmenjalna kapaciteta glinene frakcije tal (< 24cmolc kg-1 gline) ob hkratnem efektivnem deležu bazičnih kationov pod 50%. Tla z argičnim horizontom in akričnimi lastnostmi se uvrščajo v referenčno skupino Acrisols. Izprana akrična tla so se prevajala kot Acrisols, kar ne drži po merilih klasifikacije WRB in je lahko zavajajoče, predvsem za tuje bralce, ki ne poznajo tal v Sloveniji in meril slovenske klasifikacije. V prispevku smo preučili zgodovino rabe izraza akričnost v slovenski pedološki literaturi in klasifikaciji tal ter s tem izrazom povezane diagnostične lastnosti in merila. Ugotovili smo, da je bil izraz akričnost uveden leta 1973 na podlagi legende pedološke karte FAO iz leta 1968. V različnih obdobjih so uporabljali različna merila (horizonti, lastnosti, analitske metode), ki se niso posodabljala z razvojem mednarodne klasifikacije WRB. // Historical overview of the use of the term acric in Slovenian soil classification In naming and classifying soils in Slovenia, we faced challenges from the beginning, resulting from the introduction of foreign, unfamiliar terms and changes in diagnostic criteria and analytical procedures for their verification. When translating the names of Soil Systematic Units of the Soil Map of Slovenia 1:25,000 for international publications and soil maps of Europe, misunderstandings could arise. Acric soils are defined in the Soil Map of Slovenia as very acidic soils with base saturation below 35% and belong to the Illuvial soils. The WRB classification criterion for acric properties is the low cation exchange capacity of the clay fraction of the soil (< 24cmolc kg-1 clay) with a simultaneous effective base saturation below 50%. Soils with an argic horizon and acric properties are referred to as reference group Acrisols. Illuvial acric soils have been translated as Acrisols, which is incorrect according to WRB classification criteria and is misleading, especially for foreign readers unfamiliar with soils in Slovenia and Slovenian classification criteria. In this paper, we examine the history of the use of the term acric in Slovenian pedological literature and soil classification, as well as the diagnostic properties and criteria associated with this term. We found out that the term acric was introduced in 1973 based on the legend of the FAO soil map of 1968. Different criteria (horizons, properties, analytical methods) were used in the different periods, which were not updated with the development of the international WRB classification.

The aim of our study was to clarify the use of the term “acric” in the Slovenian soil classification and its relation to the Acrisols of the World reference base for soil resources. A comprehensive review of Yugoslavian and Slovenian soil literature from 1960 to the present revealed that the term “acric” was first introduced into the classification of Yugoslav soils in 1973, based on FAO Legend (1968). “Acric” properties were most often associated with Illuvial soils (soils with argic horizons) of the Dinaric karst region. A detailed review and analysis of soil properties of 81 profiles with argic horizons from the Slovenian Soil Map database were done. Results clearly showed that soils with argic horizons are neither Acrisols nor Lixisols according to the latest WRB soil classification, as no soils with low activity clay in argic horizons have been proved so far. The base saturation and some recent measurements of effective base saturation indicate that Luvisols are the predominant Illuvial soils in Slovenia, with possible development to Alisols. Inconsistent use of the term “acric,” especially in the context of its translation to WRB reference group Acrisols, can lead to misunderstandings about the properties of such soils.

Approximately 3000 food samples from the Slovenian market and 2500 drinking (tap) water samples in the period 2011 - 2016 were evaluated for the presence of toxic elements lead (Pb) and cadmium (Cd) and the overall chronic dietary exposure was assessed for each element. The highest mean concentrations were found for Pb in products for special nutritional use - dietary supplements (0.383 mg/kg) and for Cd in fish and seafood (0.117 mg/kg). The consumption data were obtained from the national study of the household budget and from the European Food Safety Authority (EFSA) summary statistics. Chronic dietary exposure was estimated deterministically. The average Pb and Cd intakes from food and drinking (tap) water ranged for children from 0.90 to 1.021 µg/kg bw/day and 4.65 to 5.65 µg/kg bw/week, respectively, and for adults, including adolescents, from 0.40 to 0.53 µg/kg bw/day and 1.98 to 2.82 µg/kg bw/week, respectively. The high consumption of cereal-based foods and vegetables contributed most to overall Pb and Cd intake in the majority of the age groups. The exposure to Pb was generally lower and that to Cd was higher compared to the average EU values. The most exposed were children, as the health-based guidance values were exceeded for both elements, which indicates a health concern. An important contribution to Cd exposure can be attributed to grains and potatoes grown in Slovenia, where the soil contains more Cd than that in other EU countries. Further efforts to reduce Pb and Cd intake are required to minimize potential health risks.

Soil contaminated with cadmium presents a potential hazard for humans, animals and plants. The latter play a major role in the transfer of cadmium to the food chain. The uptake of cadmium and its accumulation by plants is dependent on various soil, plants and environmental factors. In order to identify soil properties with statistically significant influence on cadmium concentration in vegetables and to reduce the collection of data, time and costs, regression models can be applied. The main objective of this research was to develop regression models to predict the concentration of cadmium in 9-vegetable species: zucchini, tomato, cabbage, onion, potato, carrot, red beet, endive and chicory, based on soil properties. Soil samples were collected from 123 home gardens of the Municipality of Celje and 59 of these gardens were also included in vegetable sampling. The concentration of elements (e.g. arsenic, cadmium, copper, lead, and zinc) in the samples was determined by Inductively Coupled Plasma Mass Spectrometry. Single (for cabbage, potato, red beet and chicory) and multiple (for tomato, onion, carrot and endive) linear regression models were developed. There was no statistically significant regression model for zucchini. The most significant parameter for the influencing the cadmium concentration in vegetables was the concentration of cadmium in soil. Other important soil properties were the content of organic matter, pH-value and the concentration of manganese. It was concluded that consuming carrots, red beets, endives, onions, potatoes and chicory which are grown in gardens with Cd concentrations (mg kg −1 DW) above 2.4, 3.2, 6.3, 7.9, 8.3 and 10.9, respectively, might represent an important contribution to dietary Cd exposure.

It is difficult to imagine organic chemistry without organo-halogen compounds and the molecular halogens needed for their preparation. The halogens have very different reactivity, with iodine usually requiring some form of activation, while others are reactive and hazardous chemicals. To avoid their use, various modified reagents have been discovered (N-bromo- and N-chlorosuccinimide, Selectfluor..), but halogens are used to prepare these reagents and when they are used the atom economy is poor. A better approach, which is based on biomimetric research on oxidative halogenation in nature, consists of generating the halogenating reagent in situ under acidic conditions from a halide salt. The result of such a reaction has been halogenation with 100 % halogen atom economy. Suitable oxidants for the oxidation of halides are hydrogen peroxide and oxygen.

The dual behavior phenomenon of alcohols in iodine-catalyzed esterification under solvent-free reaction conditions (SFRCs) is described; the governing factor is the stability of the carbonium ion generated from the alcohol; high concentration reaction conditions (HCRCs) or dilute solutions are much less suitable. In the case of benzylic alcohols, loss of optical activity was noted, whereas alkyl alcohols furnished a product with retention of stereochemistry.

A H 2 O 2 –HBr system and N -bromosuccinimide in an aqueous medium were used as a ‘green’ approach to electrophilic and radical bromination. Several activated and less activated aromatic molecules, phenylsubstituted ketones and styrene were efficiently brominated ‘on water’ using both systems at ambient temperature and without an added metal or acid catalyst, whereas various non-activated toluenes were functionalized at the benzyl position in the presence of visible light as a radical activator. A comparison of reactivity and selectivity of both brominating systems reveals the H 2 O 2 –HBr system to be more reactive than NBS for benzyl bromination and for the bromination of ketones, while for electrophilic aromatic substitution of methoxy-substituted tetralone it was higher for NBS. Also, higher yields of brominated aromatics were observed when using H 2 O 2 –HBr ‘on water’. Bromination of styrene reveals that not just the structure of the brominating reagent but the reaction conditions: amount of water, organic solvent, stirring rate and interface structure, play a key role in defining the outcome of bromination (dibromination vs bromohydroxylation). In addition, mild reaction conditions, a straightforward isolation procedure, inexpensive reagents and a lower environment impact make aqueous brominating methods a possible alternative to other reported brominating protocols.

Fluorous aryl and alkyl iodine(III) dichlorides of the formulas (R(fn)(CH(2))(3))(2)C(6)H(3)ICl(2) (R(fn) = CF(3)(CF(2))(n-1); n = 8 for 3,5-disubstituted and n = 6, 8, 10 for 2,4-disubstituted) and R(fn)CH(2)ICl(2) (n = 8, 10) are prepared in 71-98% yields by reactions of Cl(2) and the corresponding fluorous iodides. These are effective reagents for the conversions of cyclooctene to trans-1,2-dichlorocyclooctene, anisole to 4-chloro- and 2-chloroanisole, 4-tert-butylphenol to 2-chloro-4-tert-butylphenol, PhCOCH(2)COPh to PhCOCHClCOPh, and PhCOCH(3) to PhCOCH(2)Cl and PhCOCHCl(2) (CH(3)CN, rt to 40 degrees C, 100-64% conversions). The chlorinated products and fluorous iodide coproducts are easily separated by organic/fluorous liquid/liquid biphase workups. The latter are obtained in 97-90% yields and reoxidized with Cl(2). Analogous chlorinations are conducted with 3-Cl(2)IC(6)H(4)COOH (16) and 4,4'-Cl(2)IC(6)H(4)C(6)H(4)ICl(2). With the former, the products and coproduct 3-IC(6)H(4)COOH (91-85% recoveries) are easily separated by organic/aqueous NaHCO(3) liquid/liquid biphase workups. The coproduct from the latter, 4,4'-IC(6)H(4)C(6)H(4)I, is insoluble in common organic solvents, allowing separation by liquid/solid phase workups (91-89% recoveries). The effect of the structure of the iodine(III) dichloride upon reactivity is analyzed in detail. The fluorous systems with R(f8) substituents are generally superior, but 16 is more reactive and gives higher selectivities.

The visible-light-induced transformation of toluenes with N-bromosuccinimide (NBS) under solvent-free reaction conditions (SFRC) was studied. The reaction took place in spite of the very restricted molecular motion; toluenes could be regioselectively converted to benzyl bromides. Selective radical-chain reactions with NBS were carried out in liquid/liquid and in solid/solid systems; furthermore, reactions could be performed in the presence of air. The radical scavenger TEMPO (=2,2,6,6-tetramethylpiperidin-1-yloxy) completely suppressed the side-chain bromination of toluenes with NBS under SFRC. Electron-withdrawing groups decreased the reactivity of the toluenes, and the Hammett reaction constant ρ+=−1.7 indicated involvement of polar radical intermediates with electrophilic character.

A micellar system was developed and applied for direct regioselective fluorination of a variety of cyclic and acyclic ketones to α-fluoroketones in water as reaction medium with Selectfluor F-TEDA-BF 4 as fluorinating reagent. The inexpensive ionic amphiphile sodium dodecyl sulfate (SDS) was found to be an excellent promoter for fluorofunctionalization of hydrophobic ketones without prior activation or use of acid catalysts.

Various alkenes (internal, terminal, aryl and alkyl substituted) and 1,2-diphenylethyne were efficiently and selectively dibrominated using 2 equivalents of 48% aqueous hydrobromic acid, with air as an oxidant and sodium nitrite as a catalyst. Despite the presence of water, only trans dibromination occurred producing anti-1,2-dibromoalkanes and (E)-1,2-dibromo-1,2-diphenylethene. A comparison of resource demand, waste production and environmental, health and safety issues of the NaNO2 catalyzed aerobic bromination with molecular bromine and other oxidative bromination methods revealed that the proposed method is not only selective and effective but has a better environmental profile.

Selective and efficient iodinations of organic compounds were achieved by an aerobic oxidative process catalyzed by sodium nitrite using potassium iodide in acidic media. Using the potasasium iodide (KI)/air/sodium nitrite (NaNO 2 ; cat.)/sulfuric acid (H 2 SO 4 ) iodinating system, activated and moderately deactivated aromatic compounds were exclusively or preferentially iodinated at the para position. In protic solvents ketones and 1,3-dicarbonyl compounds were iodofunctionalized at the a carbonyl position, while in the case of aryl methyl ketones bearing an activated aromatic ring, the regioselectivity of iodination could be directed by the solvent used. In acetonitrile (MeCN) the aromatic ring was selectively iodinated, while in aqueous rethanol (EtOH) functionalization of the methyl carbon atom took place. Alkenes were transformed to vicinal iodohydrins or vicinal iodoalkoxy derivatives following Markovnikov-type regioselectivity and anti stereoselectivity, while 1,2-diiodoalkenes with preferentially E orientation were formed from alkynes.

Several aryl substituted ketones, cyclic ketones, 1,3-diketones and a β-ketoamide were halogenated with N -halosuccinimides under solvent-free reaction conditions (SFRC) at various temperatures (20–80 °C), whereas less enolized ketones required the presence of an acid catalyst ( p -toluenesulfonic acid, PTSA). Bromination of substituted acetophenones obeys first order kinetics v = k Br [ketone] and the following correlation with the keto–enol equilibrium constant: log k Br =0.3p K E + C 1 , less enolized substrates being more reactive; the moderate positive charge developed in the rate determining step was confirmed by the Hammett correlation ( ρ =−0.5). On the other hand, in cyclic ketones an opposite relation was observed: log k Br =−0.6p K E + C 2 , indicating higher reactivity of substrates with higher enolization constant ( K E ). The important role of the nature of the solvent (MeCN, MeOH) in preorganization of the ketone–NBS–PTSA mixture prior to SFRC bromination was found.

Fluorination of fluorene (1) with caesium fluoroxysulfate (CFS), 2,6-dichloro-1-fluoropyridinium tetrafluoroborate (FP-B800) and 1-fluoro-4-hydroxy-1,4-diazoniabicyclo[2.2.2]- octane bis(tetrafluoroborate) (Accufluor NFTh) occurred only on the aromatic ring in the position ortho and para to the biphenyl central bond with the ratio 2-fluoro- (2a) vs 4-fluorofluorene (2b) 1.7-2.4:1. Regioselectivity of fluorination of both open-chain analogues - diphenylmethane (3a) and biphenyl (3b) was different and more ortho-fluorinated product was formed. Furthermore, the reaction of diphenylmethane (3a) with CFS occurred also on central carbon forming benzophenone (6) and fluorodiphenylmethane (7), while fluorination with FP-B800 and Accufluor NFTh occurred only at the aromatic ring. Similar effect of the structure of fluorinating reagent on the regioselectivity was also observed with dibenzofuran (8) and its open-chain analogues diphenyl ether (10) and biphenyl (3b), where the regioselectivity of fluorination with CFS (1- (9a):2- (9b):3- (9c) = 27:46:27) was similar to fluorination with Selectfluor. Product distribution of fluorination of fluorene (1) and dibenzofuran (8) with CFS is similar to nitration and is in accordance with the calculated HOMO electron density, which indicates the presence of the electron transfer pathway.

Iodine has been shown to be an efficient catalyst for transformations of alcohols under solvent-free conditions. In the presence of 5% of iodine, tertiary alcohols underwent dehydration forming the corresponding alkenes, while in the case of 2-phenylpropane-2-ol cyclodimerisation to 1,1,3-trimethyl-3-phenylindane took place. Secondary and primary benzyl alcohols under the same conditions gave the corresponding ethers.

Mild iodination using iodine and a 30% solution of hydrogen peroxide as oxidant was performed in water. The method proved to be efficient and selective for the introduction of iodine into dimethoxybenzenes, trimethoxybenzenes, and dimethoxy- and trimethoxy-substituted acetophenones, thus significantly contributing toward a more environmentally friendly procedure than that previously reported.

Iodine has been shown to be an efficient catalyst for the selective dihydroperoxidation of ketones with aqueous hydrogen peroxide. Ketones were directly converted to their corresponding gem-dihydroperoxides using a "green" oxidant (30% aq H(2)O(2)) and a simple catalyst (iodine) under neutral conditions in acetonitrile. The yield of hydroperoxidation of various cyclic ketones was 60-98% including androstane-3,17-dione, and acyclic ketones were converted with a similar efficiency. [reaction: see text]

The effect of steric interactions on the regioselectivity of fluorination of para alkyl substituted phenols was investigated and the strong effect of size of the alkyl substituent, the structure of the F–N reagent and the solvent on the site of fluorination was established. The course of reaction obeyed a second order rate equation, while the fluorination process required higher ΔH≠ activation than oxidation or oxidative demethylation. Solvent polarity variations had a small effect on the rate of functionalisation, while an excellent Hammett correlation with ρ+=−2.3 was determined.

Various N-F reagents reacted with hexamethylbenzene (1) forming side chain substituted alkoxides or esters in protic solvents, Ritter type side chain functionalization was observed in acetonitrile in the presence of trifluoroacetic acid, while in aqueous acetonitrile solution phenyl ring transformation took place, starting with ipso attack of water and further rearrangement of the methyl group as the main process. Rearranged 2,3,4,5,6,6-hexamethylcyclohexa-2,4-dienone (7) was transformed to 5-fluoro-2,3,5,6,6-pentamethyl-4-methylenecyclohex-2-en-1-one (8) or 5-hydroxy-2,3,5,6,6-pentamethyl-4-methylenecyclohex-2-en-1-one (9). 1,2,3,4,5,6-Hexamethyl-bicyclo[2.2.0]hexa-2,5-diene reacted with F-TEDA-BF4 in the presence of water and 7 was formed in high yield. Durene (12) followed similar ipso attack of water as 1, but on the other hand 1,2,3,4-tetramethylbenzene displayed different regioselectivity and 2,3,4,5-tetramethylphenol was formed, further transforming to 4-fluoro-2,3,4,5-tetramethylcyclohexa-2,5-dienone. The functionalizations of methylbenzenes obeyed a second-order rate equation v = d[N-F]/dt = k2[N-F][substrate], and DeltaG# values between 77 and 94 kJ/mol were determined. The presence of water did not significantly influence DeltaG# but considerably affected DeltaS# and positive values were found where methyl group migration was the dominant process (9.1 J/(mol K) for 1 and 0.5 J/(mol K) for 12). A higher reactivity of durene than mesitylene (k2(MES)/k2(DUR) = 0.23) was found, supporting the assumption that single electron transfer (SET) is the dominant process in the functionalizations of methyl-substituted benzene derivatives with F-TEDA-BF4.

The oxidative system MTO/30%H 2 O 2 /HBF 4 /fluorous alcohol is promising for the selective synthesis of biologically important antimalarial dispiro-1,2,4,5-tetraoxanes by direct acid-catalysed cyclisation of various 4-substituted cyclohexanones ( 1 , R=Me, Et, t Bu, Ph, COOEt, CF 3 ). The role of the substitutent at the 4-position was important in the selectivity of formation of tetraoxane ( 2 , TO) with respect to hexaoxonane ( 3 , HO). By the use of fluorinated alcohols and under the right reaction conditions, tetraoxanes 2 were selectively formed and synthesised in 46–86% isolated yield from 4-substituted cyclohexanones 1 .

In this study the “phase-vanishing” method for diffusioncontrolled addition of a reagent (Br2) to a reaction phase via a fluorous membrane (C8F18) is combined with an additional mode of activation (visible-light) to achieve the benzyl bromination of various alkyl-substituted aromatic compounds in a concentrated solution. Benzyl bromination of p-tert-butyltoluene proceeded in various solvents including hexane and methanol, while the reaction of the neat substrate showed a similar selectivity as in carbon tetrachloride. The effect of the

Water was found to be a convenient reaction medium for functionalization of substituted anisoles using iodine in the presence of Selectfluor F-TEDA-BF(4) or hydrogen peroxide as mediators and oxidizers. Two types of functionalization were observed: iodination or oxidation. In the iodination process, two reaction routes were established. In the case of the first route, a high iodine atom economy was achieved for selective and effective iodo functionalization with a stoichiometric ratio of substrate/iodine/(mediator/oxidizer) = 2:1:1.2. An electrophilic iodination reaction process was suggested for this route, with the oxidizer converting the liberated iodide anion to iodine. For the second reaction route, a stoichiometric ratio of substrate/iodine/(mediator/oxidizer) = 1:1:1 and a lower iodine atom economy were observed; in this case, ion radical formation in the first step of the reaction was suggested. Iodine was found to be an effective catalyst for the oxidation of a hydroxy benzyl functional group to benzaldehyde using F-TEDA-BF(4). Water is an effective medium for functionalization of anisole, p-methoxy benzyl alcohol, 1-(4-methoxyphenyl)ethanone, o-dimethoxy benzene, m-dimethoxy benzene, and p-dimethoxy benzene, whereas F-TEDA-BF(4) as a mediator/oxidizer could be replaced by hydrogen peroxide in the case of the functionalization of 1-(4-methoxyphenyl)ethanone, o-dimethoxy benzene, m-dimethoxy benzene, and p-dimethoxy benzene. Water changes the type of transformation of p-methoxy benzyl alcohol.

Selective and efficient synthesis of a,a-difluoro ketones was achieved following a protocol which includes the transformation of α-methylene ketones to the corresponding n-butylimine derivatives and their further treatment with Selectfluor F-TEDA-BF 4 in acetonitrile solution at 80 °C.

Oxidative iodination of arenes was carried out with one equivalent of KI and two equivalents of 30% hydrogen peroxide in MeOH in the presence of strong acid. Reactions of various substi- tuted anisoles, phenols and anilines, as well as mesitylene and uracil, were selective and effective with very good yields of isolated halogenated aromatic molecules. Halogenated organic molecules are important compounds in pharmaceutical and agricultural chemistry, 1 and they are important synthetic intermediates in chemical synthe- sis, especially for C-C coupling reactions. 2 The use of mo- lecular halogens for direct halogenation has drawbacks in the difficult and dangerous handling of chlorine and bro- mine, while iodine is less reactive. Nature has solved this problem by evolving haloperoxidases, enzymes that oxi- dize halide salts into reactive hypohalous derivatives. 3 Its counterpart in chemistry, named oxidative halogenation, has been utilized for iodination with a plethora of catalysts and oxidants in combination with molecular iodine or less

The 3,4-dialkylsubstituted phenols: 3,4-dimethylphenol, 5-indanol, and 5,6,7,8-tetrahydro-2naphthol were used as target molecules for fluorination with the N-fluoro-1,4diazoniabicyclo[2.2.2]octane salt analogues Selectfluor TM F-TEDA and Accufluor TM NFTh. 4Fluoro-3,4-dialkylcyclohexa-2,5-dienone derivatives, as the result of an addition-elimination process, were the main, and 2-fluoro- and 6-fluoro-3,4-dialkylphenols derivatives resulting from a substitution reaction, the minor products of the fluorination process. The type of transformation was found to be independent of the structure of starting material and reagent, while these two parameters were important for the regioselectivity of the substitution reaction. The effect of the solvent on these reactions was evaluated, second order kinetics for the fluorination with F-TEDA in MeCN was established, rate konstants k2 were measured, and thermodynamic parameters for the transition state (∆H * , ∆S * , and ∆G * ) determined. A reaction pathway postulating a SET

Soil samples (0 to 5 cm) from 30 locations in the Celje region, Slovenia, an area that has been subjected to severe industrial emissions of Pb and Zn, were analyzed for selected soil properties and subjected to a six-step sequential extraction of Pb and Zn. Phyto-available forms of heavy metals: soluble in soil solution and exchangeable from soil colloids to soil solution together accounted for 0 to 1.68% of Pb and 0 to 40.8% of total soil Zn. Most of the Pb and Zn was found to reside in less labile forms bound to carbonate (2.04 to 43.5% Pb, 3.9 to 35.1% Zn), bound to Fe and Mn oxides (0 to 16.1% Pb, 1.4 to 25.4% Zn), bound to organic matter (35.8 to 71.1% Pb, 14.8 to 56.2% Zn), and in the residual fraction (10.4 to 53.4% Pb, 14.2 to 75.3% Zn). Factor analysis and stepwise multiple regression revealed that the concentration of Pb in the proposed indicator plant, narrow leaf plantain (Plantago lanceolata) did not correlate with the measured soil properties, Pb fractionation in soil, and total soil Pb. Pla...

Selective introduction of an iodine atom at the α-carbon-yl position in various aryl alkyl ketones was effectively achieved by reaction of target molecules with elemental iodine in the presence of N-F reagents. The best results were obtained by using 1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) (SelectfluorF-TEDA-BF 4 ) as the iodination mediator and methanol as the solvent. Despite a strongly activated aromatic ring, iodomethyl derivatives were thus exclusively obtained from the corresponding hydroxy and methoxy substituted acetophenone derivatives, 3-acetylindole and 2-acetylbenzofuran, while the α-iodo derivative was the main product in the case of iodination of 1,5,6,7-tetrahydro-4H-indol-4-one and 6,7-dihydro-1-benzothiophene-4(5H)-one.

Benzene derivatives bearing at least one bulky alkyl group (i-Pr or t-Bu) were selectively and effectively iodinated using elemental iodine activated by 1-(chloromethyl)-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) (Selectfluor, F-TEDA-BF 4 ). Iodine atoms were progressively introduced at the most electron-rich and sterically less hindered position on the benzene ring. Not more than three iodine atoms could be progressively bonded to a target molecule bearing a i-Pr or t-Bu group.

The kinetics of reactions of hindered phenols (2,4,6-trimethylphenol, 2,6-di-tert-butyl-4-methylphenol and 2,4,6-tri-tert-butylphenol) with 1-fluoro-4-chloromethyl-1,4-diazoniabicyclo [2.2.2]octane bis(tetrafluoroborate) (Selectfluor™, F-TEDA-BF4) in acetonitrile in the absence or presence of various sources of external nucleophile (alcohols, water, trifluoroacetic acid) were studied. The reactions exhibited overall second-order kinetics, whereas products formation was strongly dependent on reaction conditions. Fluorination took place in neat MeCN; in the presence of water or alcohols, para quinols or para quinol ethers were formed exclusively; under acidic conditions (TFA), Ritter-type amidation was found to be the predominant process. Values for second-order rate constants k2 were found to be dependent on the structure of the target phenol and decreased with bulkiness of the substrate. Methanol slightly increased the rate, whereas water decreased it considerably. Activation enthalpies (between 72 and 78 kJ mol−1) and activation entropies (between −5 and −42 J mol−1 K−1) were obtained. Activation entropies were found to be higher for less-hindered substrates, indicating that the rate-determining steps were mainly regulated by steric factors. Grunwald–Winstein correlation of log k2 with solvent ionizing power Y revealed a relatively small correlation factor m. An electron-transfer-type process following the rate-determining formation of substrate–reagent complex was postulated as the key step of the reaction pathway. Copyright © 2001 John Wiley & Sons, Ltd.

Liquid phase fluorination of norbornene with 1-chloromethyl-4-fluoro-1,4-diazonia[2.2.2]octane bis(tetrafluoroborate)—F-TEDA resulted in the formation of two rearranged Ritter type products: 2-exo-acetamido-7-syn-fluoro norbornane and 2-exo-acetamido-7-anti-fluoro norbornane in 1:1 ratio in acetonitrile, while the presence of an external nucleophile, e.g. water or methanol resulted in formation of two additional rearranged products: 2-exo-hydroxy or methoxy -7-syn-fluoro norbornane and 2-exo-hydroxy or methoxy-7-anti-fluoro norbornane. Fluorination of cycloalkenes obeys a simple second order rate equation, relative rates close to unity were found for norbornene/cyclohexene and cyclopentene/cyclohexene pairs. Activation parameters were determined for cycloalkenes in acetonitrile–water (ΔH‡=14 kcal mol−1 and ΔS‡=−20 cal mol−1K−1 for norbornene), while the Winstein–Grunwald solvent polarity variation had negligible effect.

Kinetic studies on fluorination of α-substituted styrenes with 1-fluoro-4-hydroxy-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) (AccufluorTM NFTh) in acetonitrile or in acetonitrile in the presence of methanol or water as nucleophiles were carried out. These reactions exhibited overall second-order kinetics and formed Markovnikov type products. The corresponding second-order rate constants for fluorination of the studied substrates in the presence of methanol at 38.8 °C are: k2 = 1.1 × 10−3 M−1 s−1 for styrene (1a), 3.3 × 10−2 M−1 s−1 for α-methylstyrene (1b) and 3.4 × 10−2 M−1 s−1 for 1,1-diphenylethene (1c). The substitution of methanol as nucleophile by water had very little effect on the rate of the process. Solvent polarity variation (Grunwald–Winstein Ybenzyl) showed a similar small effect, too, indicating negligible change in the polarity of the rate-determining transition state in comparison with the reactants. Activation enthalpies (between 62 and 80 kJ mol−1) and activation entropies (between −74 and −32 J mol−1 K−1) were determined for fluorination of α-substituted styrenes with NFTh in acetonitrile in the presence of methanol and water as nucleophiles. Hammett correlation analysis of the reaction of substituted styrenes with NFTh in MeCN, MeCN–H2O and MeCN–MeOH gave reaction constants ρ+ of −1.48, −1.52 and −1.80, respectively, which support our belief in the mainly non-polar character of the rate-determining transition state of the studied reactions.

4-Fluorocyclohexa-2,5-dienone derivatives were obtained in high yield by reaction of para substituted phenols with 1-fluoro-4-chloromethyl-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoro-borate) (1a, SelectfluorTM F-TEDA-BF4) or its 4-hydroxy analogue (1b, AccufluorTM NFTh) in acetonitrile. Estrogen steroids were readily converted to 10β-fluoro-1,4-estradiene-3-one derivatives in high yields.

Aerobic oxidative iodination activated by sodium nitrite occurs effectively and selectively with 100% iodine atom economy with air as the oxidant. Silica-supported sulfuric acid was used for the activation of the catalyst and iodination. Thus, I2/NaNO2/air/silica-supported H2SO4 in acetonitrile iodinated aromatics, ketones and aldehydes effectively at ambient temperature.

Crosslinked copoly(styrene-p-nitrophenylacrylates), containing 2% (1 )o r 4% DVB (2) were converted with various diaminoalkanes (1,2-diaminoethane 3a, 1,4- diaminobutane 3b, 1,8-diaminooctane 3c) to amides. The degree of additional crosslink- ing depended on the chain length of the diaminoalkane, the molar ratio of ester function in 1 or 2 to diaminoalkane, solvent polarity (dimethylformamide, chloroform, toluene), while reaction temperature (50 or 1007C) had only a minor effect. 2 was also converted with various amines bearing additional functional groups (ethanolamine, 3-amino-1- propanol, 4-aminomethylpyridine, 2-(2-aminoethylamino)-ethanol, 2-(2-aminoeth- oxy)-ethanol, 6-aminocaproic acid, N-propylaminomorpholine, 3-N,N-diethylamino-1- propylamine) to the corresponding amides. The swelling ability of the resins depended on the crosslinking of the starting copoly(styrene-p-nitrophenylacrylate) (1, 2), the structure of the amide, the degree of additional crosslinking, and solvent polarity (chlo- roform, dimethylformamide, methanol, toluene). The accessibility of nitrogen atoms in the polymer matrix was examined by EtX functionalization of the 3-N,N-diethylamino- 1-propylamine derivative (10) and 4-aminomethylpyridine derivative (13), and more than 85% functionalization was found. q 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1699-1706, 1998

An aqueous solution of hydrogen peroxide and hydrogen bromide illuminated by a 40 W incandescent light bulb serves as a source of bromine radicals. Various substituted toluenes (H, Me, t Bu, Br, COOEt, COPh, NO 2 ) were brominated at the benzyl position. This haloperoxidase-like system for benzylic bromination does not require the presence of metal ions or an organic solvent for efficient conversion of methyl-arenes to benzyl bromides.

The reactions of caesium fluoroxysulphate in MeCN suspension at room temperature with di-benzyl, di-alkyl or benzyl-alkyl ethers resulted in oxidative cleavage of the ethers forming pairs of corresponding aldehydes and alcohols, which could be further transformed into acid fluorides under the reaction conditions used. Di-benzyl ether was thus transformed to a mixture of benzyl alcohol, benzaldehyde and benzoyl fluoride as the main products and benzyl benzoate as the a minor one, while di-n-hexyl ether resulted in a mixture of n-hexanol, hexanal, hexanoyl fluoride and hexyl hexanoate. The reaction of benzyl hexyl ether resulted in a mixture of benzaldehyde, benzoyl fluoride and hexanol as the main, and benzyl alcohol, hexanal, hexanoyl fluoride and hexyl benzoate as the minor products. A reaction mechanism including radical intermediates was proposed.