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The upcycling of waste biomass into valuable materials by resource‐efficient chemical transformations is a prime objective for sustainable chemistry. This approach is demonstrated in a straightforward light‐driven synthesis of polyols and polyurethane foams from the multi‐ton waste products of cashew nut processing. The photo‐oxygenation of cardanol from nutshell oil results in the formation of synthetically versatile hydroperoxides. The choice of the workup method (i. e., reduction, hydrogenation, epoxidation) enables access to a diverse range of alcohols with tunable alkene and OH functions. Condensation with isocyanates to give rigid polyurethane foams provides a resource‐efficient waste‐to‐value chain that benefits from the availability of cardanol and installation of OH groups from aerial O2., A tough nut to crack: The upcycling of waste biomass into valuable materials is a prime objective for sustainable chemistry. The multi‐ton waste cashew nut shell liquid is used in the light‐driven synthesis of polyols with tunable OH contents and in the subsequent preparation of rigid polyurethane foams.

A series of 1,3,4-oxadiazole-2-thiol derivatives bearing various alkyl or aryl moieties were designed, synthesized, and characterized using modern spectroscopic methods to yield 17 compounds (6a-6q) that were screened for acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes in the search for 'lead' compounds for Alzheimer's disease treatment (AD). The compounds 6q, 6p, 6k, 6o, and 6l showed inhibitory capability against AChE and BChE, with IC

The use of carbohydrate thiolates for facile, high-yielding, regio- and stereoselective nucleophilic substitution reactions of complex pentafluorophenyl-substituted porphyrinoids is reported. The title reaction has successfully been applied to calix[4]phyrin, calix[6]phyrin, and [28]hexaphyrin substrates. The novel glycoporphyrinoid products with their extraordinary structures and unique photophysical properties are soluble in aqueous solutions and can serve as platforms for applications in biomedicine, catalysis, coordination, or redox chemistry.

The use of carbohydrate thiolates for facile, high-yielding, regio- and stereoselective nucleophilic substitution reactions of complex pentafluorophenyl-substituted porphyrinoids is reported. The title reaction has successfully been applied to calix[4]phyrin, calix[6]phyrin, and [28]hexaphyrin substrates. The novel glycoporphyrinoid products with their extraordinary structures and unique photophysical properties are soluble in aqueous solutions and can serve as platforms for applications in biomedicine, catalysis, coordination, or redox chemistry.

We here present a highly efficient and high yielding procedure for the preparation of 2-vinyl tetrahydrofurans starting from α-hydroxymethyl tetrahydrofurans. Best results for this dehydration were achieved using Burgess' reagent in dioxane under microwave irradiation. A range of functional groups as well as different cyclic and bicyclic frameworks were found to be compatible with the reaction conditions. The desired products were obtained within minutes in good to high yields and excellent regioselectivity.

A flexible and efficient synthesis of the potent human topoisomerase inhibitor (5Z,9Z)-eicosa-5,9-dienoic acid was explored; the presented method represents a generally applicable approach towards demospongic acids and related natural products. Key steps of the synthesis involve chemoselective hydroboration, Corey–Fuchs alkynylation, Z-selective Lindlar reduction, tetrapropylammonium perruthenate catalyzed direct oxidation of a primary alcohol to the corresponding acid, and Arndt–Eistert homologation. Thus, the total synthesis of (5Z,9Z)-eicosa-5,9-dienoic acid was achieved in 10 steps in an overall yield of 20 %.

Eine regio- und stereoselektive inverse Prenylierung von Indol- und Tryptophan-Derivaten wird prasentiert. Alle vier moglichen Stereoisomere sind durch diese Iridium-katalysierte Reaktion zuganglich. Die Stereoselektivitat wird durch eine Kombination aus chiralem Phosphoramidit-Liganden mit einem achiralen Boran-Additiv gesteuert und kann abhangig von der Art des Borans vollstandig umgekehrt werden. Es genugt somit nur ein Enantiomer des Liganden, um alle denkbaren Stereoisomere herzustellen. Das synthetische Potential der Methode wurde in einer kurzen Synthese von Amauromin und seinen zwei naturlichen Diastereomeren demonstriert.

The cytospolides are a novel group of fungal secondary metabolites first described in 2011. Although all 17 natural derivatives share the same C-14 polyketide backbone, they exhibit a fairly broad structural diversity regarding their oxygenation and acetylation pattern as well as macrolide structure, e.g., monocyclic nonanolide core or bicyclic ring systems with a bridging THF ring. In the present work, the prospects for an extension of the structural diversity of cytospolides have been investigated. On the basis of a previously established synthesis of cytospolide D, a modified route to a truncated analogue carrying an alkyne instead of the natural n-pentyl side chain has been developed. In a bioinspired approach the so-derived cytospolide D alkyne analogue has been further converted to bicyclic and THF ring containing derivatives with a different backbone architecture. Finally, Sonogashira couplings or Huisgen-Sharpless click reactions have been used for late-stage diversifications. Thus, a set of 15 novel and structurally diverse natural product derivatives has been synthesized in a highly efficient manner.

Common photoredox catalysts Ru(bpy)3(2+) and Ru(bpz)3(2+) are rapidly converted into Ruthenium(viii)-oxide through continuous visible light irradiation in the presence of NaIO4 or H5IO6. This hitherto unreported photoassisted catalyst oxidation was utilized in the development of tandem catalytic protocols which combine a photoredox reaction with a subsequent RuO4-mediated oxidation. The new concept was demonstrated through one-pot radical cation Diels-Alder (RCDA)/1,5-diene cyclisation sequences.

This review focuses on the application of glycol cleavage reactions in the synthesis and derivatization of complex natural products. Reagent classics as well as recent developments are discussed. 1 Introduction 2 Mechanistic Aspects 3 Reagents and Examples 3.1 Periodate and Hypervalent Iodine 3.1.1 Periodic Acid and Periodates 3.1.2 Periodate on Wet Silica Gel 3.1.3 Phenyliodine Diacetate 3.1.4 Other Iodine Reagents 3.2 Lead Tetraacetate 3.3 Chromium Reagents 3.3.1 Pyridinium Chlorochromate 3.3.2 Other Chromium Reagents 3.4 Ruthenium Reagents 3.4.1 Tetra- n -propylammonium Perruthenate 3.4.2 Other Ruthenium Reagents 3.5 Manganese Reagents 3.5.1 Manganese(III) Acetate 3.5.2 Manganese Dioxide 3.5.3 Other Manganese Reagents 3.6 Miscellaneous 4 Conclusion

The synthesis of 2-nitro-4-oligoprenyl-substituted pyrrole derivatives relevant to the heronapyrroles and related natural products was investigated. Among numerous approaches, nitration of a 3-farnesyl-substituted unprotected pyrrole using AcONO2 gave the best results, albeit still with unsatisfactory yield and regioselectivity. Therefore, the synthesis of (-)-heronapyrrole C acid, an analogue of the naturally occurring antibiotic heronapyrrole C carrying a bioisosteric carboxylate in place of the nitro group, was examined. In lieu of the unsatisfactory nitration, a regioselective acylation with Cl3CCOCl was carried out (>8:1 regioselectivity, in contrast to the 1:1.3 ratio for the nitration). The trichloromethyl ketone was converted to the desired acid in a haloform reaction at the final stage of the synthesis. Further key steps of the analogue synthesis involved a position- and stereoselective Corey-Noe-Lin dihydroxylation and an organocatalytic double Shi epoxidation. A biomimetic polyepoxide cyclization cascade established the bis-THF backbone. Thus, (-)-heronapyrrole C acid was synthesized in eight steps (14.5% overall yield) from commercially available starting materials.

A new method to accomplish glycol cleavage to carboxylic (di)acids in one step using catalytic amounts of tetrapropylammonium perruthenate (TPAP) together with N-methylmorpholine N-Oxide (NMO) as the stoichiometric oxidant is presented. In addition to regenerating the active catalyst, the N-oxide stabilizes intermediary carbonyl hydrates and thereby shifts a crucial equilibrium. The mild oxidation protocol is applicable to a broad range of substrates providing the respective acids, diacids, or keto acids in high yields.

We present a simple, mild, and highly effective method for the direct conversion of primary alcohols to carboxylic acids. TPAP serves as the catalyst, and NMO·H(2)O plays a dual role, acting as the co-oxidant and as a reagent for aldehyde hydrate stabilization. This previously unknown stabilizing effect of geminal diols by N-oxides is the key for the efficiency of the overall transformation.

The trichloroacetimidate method has been utilized for the glycosylation of porphyrins. The corresponding glycoconjugates were obtained rapidly, in high yields, and excellent purity. A three-step sequence using well-matched (Lewis) acids was found to be highly effective and reliable.

The kinetics of the liquid-phase oxidation of cyclooctene by molecular oxygen catalyzed by VB2 on initial stages of process was studied. The vanadium diboride was found to activate the oxidation process in the presence of hydroperoxide in the reaction system. It was shown by FTIR investigation that cyclooctene and hydroperoxide are complexed with the same catalytic center. The reaction rate depended on cyclooctene concentration with less than first order. In the investigation system the radicals are formed as a result of proceeding of two processes—noncatalytic and catalyzed by vanadium diboride bimolecular decomposition of tert-butyl hydroperoxide. Based on the obtained data the kinetic model of the investigated process was proposed. The equation for the reaction rate was derived from this model. This equation is allowed to describe all observed kinetic dependences.

An α-deprotonation of carbonyl compounds with phosphazene bases in the presence of the internal quenching reagent, nonafluorobutane-1-sulfonyl fluoride furnishes the corresponding alkenyl nonaflates. The new general method provides high yields of alkenyl nonaflates from aldehydes and cyclic ketones. However, it is not applicable to acyclic ketones whose nonaflate derivatives undergo fast E2 elimination to give alkynes. Successful synthesis of nonaflates from aldehydes requires carefully controlled reaction conditions to avoid the subsequent elimination to alkynes. A kinetic control enables high regioselectivities in favor of least substituted nonaflate regioisomers derived from cyclic ketones and modest Z-selectivities of alkenyl nonaflates derived from aldehydes. A new efficient protocol for highly selective removal of perfluorosulfolane admixture from technical nonafluorobutane-1 -sulfonyl fluoride by basic hydrolysis is described.

A highly efficient protocol for the large-scale oxidative cyclization of 1,5-dienes is described. This convenient ruthenium(VIII)-catalyzed (0.2 mol%) cyclization reaction allows the preparation of cis-2,5-disubstituted tetrahydrofurans in high yields (up to 92%) and excellent diastereomeric ratio (>95:5 dr). This simple and reliable method is insensitive to moisture and air and can, therefore, be carried out in an open reaction vessel.

The asymmetric dihydroxylation reaction of early stage and advanced Bryostatin C-ring precursors was evaluated. For homoallylic ethers and alcohols, several AD ligands were investigated including a novel class of quinidine-alkynes.

The analysis of a candidate biosynthetic gene cluster (97 kbp) for the polyether ionophore monensin from Streptomyces cinnamonensis has revealed a modular polyketide synthase composed of eight separate multienzyme subunits housing a total of 12 extension modules, and flanked by numerous other genes for which a plausible function in monensin biosynthesis can be ascribed. Deletion of essentially all these clustered genes specifically abolished monensin production, while overexpression in S. cinnamonensis of the putative pathway-specific regulatory gene monR led to a fivefold increase in monensin production. Experimental support is presented for a recently-proposed mechanism, for oxidative cyclization of a linear polyketide intermediate, involving four enzymes, the products of monBI, monBII, monCI and monCII. In frame deletion of either of the individual genes monCII (encoding a putative cyclase) or monBII (encoding a putative novel isomerase) specifically abolished monensin production. Also, heterologous expression of monCI, encoding a flavin-linked epoxidase, in S. coelicolor was shown to significantly increase the ability of S. coelicolor to epoxidize linalool, a model substrate for the presumed linear polyketide intermediate in monensin biosynthesis.

This review focuses on the application of glycol cleavage reactions in the synthesis and derivatization of complex natural products. Reagent classics as well as recent developments are discussed. 1 Introduction 2 Mechanistic Aspects 3 Reagents and Examples 3.1 Periodate and Hypervalent Iodine 3.1.1 Periodic Acid and Periodates 3.1.2 Periodate on Wet Silica Gel 3.1.3 Phenyliodine Diacetate 3.1.4 Other Iodine Reagents 3.2 Lead Tetraacetate 3.3 Chromium Reagents 3.3.1 Pyridinium Chlorochromate 3.3.2 Other Chromium Reagents 3.4 Ruthenium Reagents 3.4.1 Tetra- n -propylammonium Perruthenate 3.4.2 Other Ruthenium Reagents 3.5 Manganese Reagents 3.5.1 Manganese(III) Acetate 3.5.2 Manganese Dioxide 3.5.3 Other Manganese Reagents 3.6 Miscellaneous 4 Conclusion

A low-temperature (-95 degrees C) protocol for intermolecular cycloadditions of furan to chiral silyloxyallyl cations in dichloromethane is described. Key precursors are open-chain, mixed a-ketoacetals, which are chiral. The resulting [4+3] cycloadducts are densely functionalized and are isolated as single enantiomers in high chemical yield. The yield of the cycloadducts increases with increasing dilution. Three and four stereogenic centres are created in one single step.

Current European Union legislation will increase the level of disposal of sewage sludge to agricultural land in the next 10 years. This increase may lead to an increase in ingestion, by grazing animals, of herbage with elevated levels of potentially toxic elements (PTEs) derived from sludge adhered to the herbage or sewage sludge-amended soil resulting in the accumulation of PTEs in body tissues, especially the liver and kidney. To assess the possible accumulation of PTEs from soils treated historically with sewage sludge, eight groups of housed weaned lambs were given either dried grass as a sole food (grass control), or diets comprising dried grass (0·9 of total diet dry matter (DM)) and soil (0·1 of total diet DM) from two experimental sites, plots within which had been treated 14 years previously with different quantities of sewage sludge. Soils from the two sites (Cassington and Royston) had contrasting physical characteristics, pH and contents of calcium. The soil from the site at Cassington was slightly acidic (pH 6·0) and had a concentration of calcium of 7·92 g/kg DM whereas the soil from the site at Royston was alkaline (pH 8·0) and had a high concentration of calcium (23·5 g/kg DM). Plots at each site had a range of concentrations of cadmium (Cd) in the soil up to three times the United Kingdom (UK) statutory limit of 3 mg Cd per kg DM. The soils from these two sites were designated control — no amendment with sewage sludge (0·69 mg Cd per kg DM), low (3·55 mg Cd per kg DM), medium (6·63 mg Cd per kg DM) and high (8·82 mg Cd per kg DM; Cassington soil only). Voluntary DM intake of diets by weaned lambs (mean 1436 glday) was not affected significantly by any dietary treatment. The concentrations of Cd in liver increased (P < 0·001) from 0·061 and 0·072 mg/kg DM (Royston and Cassington control, respectively) to 0·218 and 0·403 mg/kg DM (Royston and Cassington medium, respectively) and 0·500 mg/kg DM (Cassington high). The concentrations of Pb in liver increased (P < 0·001) from 0·733 and 0·627 mg/kg DM (Royston and Cassington control, respectively) to 118 and 1·25 mg/kg DM (Royston and Cassington medium, respectively) and 1·18 mg/kg DM (Cassington high). Similar changes were observed for concentrations of Cd and Pb in kidney. A depletion of the concentration of Cu in the liver was observed in all treatments containing soil in the diet. The rate of accumulation of Cd in the liver ranged from 0 to 0·35 μg/g daily tissue DM growth and in the kidney ranged from 0 to 0·44 μg/g daily tissue DM growth. The rate of accumulation of Pb in the liver ranged from 0 to 6·01 μg/g daily tissue DM growth and in the kidney ranged from 0 to 0·63 μg/g daily tissue DM growth. No significant accumulation of PTEs was observed in muscle tissue. It is concluded that the current UK statutory limits for the concentrations ofCd and Pb in soils treated with sewage sludge should be reviewed in the light of these results, though they require confirmation in the grazing situation.

Increasing amounts of sewage sludge will be applied to agricultural land over the next 10 years as a result of the prohibition of its disposal to the sea. The addition of potentially toxic elements (PTEs) to the soil via sewage sludge is controlled by European legislation designed to limit the accumulation of PTEs in soil which could give rise to toxicity to plants or livestock. However the possibility exists that direct ingestion of sewage sludge and soil together with grazed herbage may result in accumulation of PTEs in body tissues. To assess the extent of accumulation of PTEs by direct ingestion of soil and sewage sludge 12 groups of housed weaned lambs were given diets ad libitum comprising dried grass (900 g/kg total diet dry matter (DM)) and three different soils (100 glkg total diet DM). Soil was replaced by dried digested sewage sludge at levels ofO (level 0), 75 (level 1), 150 (level 2) and 300 g/kg soil DM (level 3). Voluntary intake of DM was markedly depressed by the inclusion of sewage sludge in the diet (on average by 24 g DM per g sewage sludge DM addition). There was no effect of sewage sludge on diet apparent digestibility. Live-weight gain was depressed (P < 0·001) by the addition of sewage sludge to the diet from 236 glday (level 0) to 141 glday (level 3). Liver and kidney weights were also reduced (P < 0·01). The apparent availability coefficients for Cd, Pb and Cu increased with increasing level of sewage sludge in the diet fP < 0·05), as did their concentrations in the liver and kidney (P < 0·01). Concentrations of Cd and Pb in liver increased from

Fractal and multifractal techniques have been applied to various types of solar data to study the fractal properties of sunspots as well as the distribution of photospheric magnetic fields and the role of random motions on the solar surface in this distribution. Other research includes the investigation of changes in the fractal dimension as an indicator for solar flares. Here we evaluate the efficacy of two methods for determining the fractal dimension of an image data set: the Differential Box Counting scheme and a new method, the Jaenisch scheme. To determine the sensitivity of the techniques to changes in image complexity, various types of constructed images are analyzed. In addition, we apply this method to solar magnetogram data from Marshall Space Flight Centers vector magnetograph.

Efficient shielding of the π face is offered by the phenyl group of the chiral auxiliary (TES=triethylsilyl) to the allyl cation generated at low temperature from 1. This protection induces high π-facial selectivity and allows high chemical yield on the capture of the cation by furan to afford the title cycloadduct 2.

The analysis of a candidate biosynthetic gene cluster (97 kbp) for the polyether ionophore monensin from Streptomyces cinnamonensis has revealed a modular polyketide synthase composed of eight separate multienzyme subunits housing a total of 12 extension modules, and flanked by numerous other genes for which a plausible function in monensin biosynthesis can be ascribed. Deletion of essentially all these clustered genes specifically abolished monensin production, while overexpression in S. cinnamonensis of the putative pathway-specific regulatory gene monR led to a fivefold increase in monensin production. Experimental support is presented for a recently-proposed mechanism, for oxidative cyclization of a linear polyketide intermediate, involving four enzymes, the products of monBI, monBII, monCI and monCII. In frame deletion of either of the individual genes monCII (encoding a putative cyclase) or monBII (encoding a putative novel isomerase) specifically abolished monensin production. Also, heterologous expression of monCI, encoding a flavin-linked epoxidase, in S. coelicolor was shown to significantly increase the ability of S. coelicolor to epoxidize linalool, a model substrate for the presumed linear polyketide intermediate in monensin biosynthesis.

Xanthomonas maltophilia was transformed with the gene encoding Vitreoscilla (bacterial) hemoglobin, vgb, and the growth of the engineered strain was compared with that of the untransformed strain using benzoic acid as the sole carbon source. In general, growth of the engineered strain was greater than that of the untransformed strain; this was true for experiments using both overnight cultures and log phase cells as inocula, but particularly for the latter. In both cases the engineered strain was also more efficient than the untransformed strain in converting benzoic acid into biomass.

Surface sensitive C1s core level photoelectron spectroscopy was used to examine the electronic properties of C(60)F(48) molecules on the C(100):H surface. An upward band bending of 0.74 eV in response to surface transfer doping by fluorofullerene molecules is measured. Two distinct molecular charge states of C(60)F(48) are identified and their relative concentration determined as a function of coverage. One corresponds to ionized molecules that participate in surface charge transfer and the other to neutral molecules that do not. The position of the lowest unoccupied molecular orbital of neutral C(60)F(48) which is the relevant acceptor level for transfer doping lies initially 0.6 eV below the valence band maximum and shifts upwards in the course of transfer doping by up to 0.43 eV due to a doping induced surface dipole. This upward shift in conjunction with the band bending determines the occupation of the acceptor level and limits the ultimately achievable hole concentration with C(60)F(48) as a surface acceptor to values close to 10(13) cm(-2) as reported in the literature.

Two general approaches in the development of light-crosslinkable resin systems with very good end-properties are summarised: (1) photoinitiation of the cationic polymerisation of epoxy resins, and (2)‘dual-functionality’ epoxies. The major known photoinitiators for epoxy cure are surveyed, and in particular various sulphonium salt types. Recent observations on sulphoxonium salts of different kinds, as new catalysts for the photo-cure of epoxy resins, are described.

The molecular weight distributions of resins produced by reaction of formaldehyde with phenols, melamine, or urea have been studied by gel permeation chromatography.

The marginality component of personality appears appropriate for men who hold integrative management positions. Research reveals an association between the Self-Other Orientation measure of margina...

The article reports on the concept of marginality as it applies to industrial organization and industrial management. The author focuses on ways in which marginality affects job satisfaction and in...

SummaryIonophoric polyethers are produced by the exquisitely stereoselective oxidative cyclization of a linear polyketide, probably via a triepoxide intermediate. We report here that deletion of either or both of the monBI and monBII genes from the monensin biosynthetic gene cluster gave strains that produced, in place of monensins A and B, a mixture of C-3-demethylmonensins and a number of minor components, including C-9-epi-monensin A. All the minor components were efficiently converted into monensins by subsequent acid treatment. These data strongly suggest that epoxide ring opening and concomitant polyether ring formation are catalyzed by the MonB enzymes, rather than by the enzyme MonCII as previously thought. Consistent with this, homology modeling shows that the structure of MonB-type enzymes closely resembles the recently determined structure of limonene-1,2-epoxide hydrolase from Rhodococcus erythropolis.

The internal reproductive systems of both sexes of Hydroperla crosbyi (Needham and Claassen) are generally similar to those of Arcynopteryx compacta (McLachl.). Sperm transfer is external, to a depression around the female genital opening formed by a 'packing action" of the male epiproct during what appears superficially to be copulation. Sperm are deposited in the depression after a spontaneous aedeagal eversion lasting 0.5-1.5 min. The aedeagus does not function as an intromittent organ. Sperm are aspirated by the female after the releaser consisting of cercal brushing or tapping by the male. This represents a previously unreported means of sperm conveyance in the Plecoptera and among the Insecta. Potential contribution of reproduction knowledge to phylogeny in the Perlodidae is discussed.