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In many reactions involving selenosulfonate or thiosulfonate, the sulfone group often leaves in form of benzenesulfinic acid or sodium benzenesulfinate. A one-pot two-step reaction of selenosulfonate with isocyanides and allyl alcohol under aqueous conditions to afford selenocarbamates and allyl sulfone compounds is reported. The sulfinic acid as the first-step side product is converted to the allyl sulfone compound by water promoted reaction with allyl alcohol. Water acts as both an oxygen source of selenocarbamates and as a promoter to drive the second step reaction. The reactions have the advantages of mild conditions, green, environment-friendly, and high atomic economy.

A study on the reactivity of NHC cobalt half-sandwich complexes [(η5-C5R15)Co(R22Im)(η2-C2H4)] (R1 = H; R2 = Me 1, iPr 2) and [(η5-C5R15)Co(R22Im)(η2-C2H3{SiMe3})] (R1 = H, R2 = Me 3, iPr 4; R1 = Me, R2 = Me 5, iPr 6) towards selected perfluoroarenes is presented (R2Im = 1,3-di(organyl)-imidazolin-2-ylidene). The reaction with hexafluorobenzene, perfluorotoluene and decafluorobiphenyl at 100 °C led to the isolation of the cobalt(II) complexes [CpCo(iPr2Im)(C6F5)] 7, [CpCo(iPr2Im)(C7F7)] 8, [CpCo(iPr2Im)(C12F9)] 9, [Cp*Co(iPr2Im)(C6F5)] 10, [Cp*Co(iPr2Im)(C7F7)] 11 and [Cp*Co(iPr2Im)(C12F9)] 12 (Cp* = η5-C5{CH3}5), Cp = η5-C5H5). The cobalt(II) fluoride [CpCo(iPr2Im)(F)] was detected as a side product of these reactions. The reaction of [CpCo(R22Im)(η2-C2H4)] (R2 = Me 1, iPr 2) with C6F6 and C7F8 at 60 °C afforded the dinuclear complexes [{CpCo(R22Im)}2(μ-η2,η2-C6F6)] (R2 = Me 13, iPr 14) and [{CpCo(R22Im)}2(μ-η2,η2-C7F8)] (R2 = Me 15, iPr 16). Furthermore, the dinuclear complexes [{CpCo(Me2Im)}2(μ-η2,η2-C10F8)] 17, [{CpCo(iPr2Im)}2(μ-η2,η2-C10F8)] 18 and mononuclear [CpCo(iPr2Im)(η2-C10F8)] 19 were isolated from the reaction of 1 and 2 with octafluoronaphthalene at room temperature. Based on the experimental data a mechanism is proposed for the C–F bond activation of perfluoroarenes with complexes [Cp(*)Co(NHC)(olefin)]. Transfer of [Cp(*)Co(NHC)] to the perfluoroarene, which is limited by the activation barrier to replace the alkene ligand, affords mononuclear cobalt complexes [Cp(*)Co(NHC)(η2-ArF)]. Ligand dismutation at higher temperatures leads to dinuclear complexes [{Cp(*)Co(NHC)}2(μ-η2,η2-ArF)], which are precursors for the formation of the cobalt(II) complexes [Cp(*)Co(NHC)(ArF)] and [Cp(*)Co(NHC)(F)]. One electron oxidative addition prevails in the C–F bond activation step using these cobalt half-sandwich complexes.

Bio-based monomers represent the future market for polymer chemistry, since the political economics of different states promote green ventures toward more sustainable materials and processes. Industrial pulp and paper processing represent a large market that could advance the use of by-products to avoid waste production and reduce pollution. Lignin represents the most available side product that can be used to produce a bio-based monomer. This review is concentrated on the possibility of using bio-based monomer derivates from pulp and the paper industry for UV-curing processing. UV-curing represents the new frontier for thermoset production, allowing a fast reaction cure, less energy demand, and the elimination of solvent. The growing demand for new monomers increases research in the environmental field to substitute for petroleum-based products. This review provides an overview of the main monomers and relative families of compounds derived from industrial processes that are suitable for UV-curing. Particular focus is given to the developments reached in the last few years concerning lignin, rosin and terpenes and the related possible applications of these in UV-curing chemistry.

This report describes an ideal cascade model of uranium enrichment that includes side feed and side product streams and flexible input options. This model is based on the original MSTAR model developed by Edward Von Halle and furnished to the International Atomic Energy Agency (IAEA) in 1996. The current version includes more flexible input and output options which allow the user to specify a variety of input combinations. This flexibility allows specification of integer numbers of stages or the stage numbers of external flows instead of assays.

The hypercoordinated silicon chlorides ClSi[(o-OC6H4)3N] (3) and ClSi[(OC6H2Me2CH2)3N] (5) were used for the synthesis of catenated derivatives (Me3Si)3SiSi[(o-OC6H4)3N] (9), (Me3Si)3SiSiMe2SiMe2Si(SiMe3)2Si[(o-OC6H4)3N] (11), and (Me3Si)3SiSi[(OC6H2Me2CH2)3N] (13) in reactions with (Me3Si)3SiK·THF (7) or (Me3Si)3SiK·[18-crown-6] (8). It was found that the nature of the (Me3Si)3SiK solvate determines the product of interaction, resulting in the formation of (Me3Si)3Si(CH2)4OSi[(OC6H2Me2CH2)3N] (12) or 13. Compounds obtained were characterized using multinuclear NMR and UV-vis spectroscopy and mass spectrometry. The molecular structures of 3, 9, and 11-13 were investigated by single-crystal X-ray analysis, featuring hypercoordinated Si atoms in a trigonal-bipyramidal coordination environment with O atoms in the equatorial plane. The structure of the side product [N(CH2C6H2Me2O)3Si]2O (6) was also studied, indicating highly tetrahedrally distorted trigonal-bipyramidal environment at the Si atoms, which was confirmed by crystal density functional theory calculations indicating the very weak Si ← N interaction. The Si···N interatomic distances span a broad range (2.23-2.78 A). The dependence of structural and NMR parameters for hypercoordinated catenated compounds from the type of the ligand was established.

During the process of catalytic conversion of CO2 to valuable chemical products, Pd used as catalysts or modifiers shows promising effect on CO2 hydrogenation. The mechanism of methanol synthesis from the hydrogenation of CO2 on the Pd(111) surface was studied using density functional theory calculations in present work. On the Pd(111) surface, CO2 firstly hydrogenates to HCOO or COOH, each of which then reacts with the surface H atom to form HCOOH. Next, HCOOH dissociates to OH and HCO that will be consecutively hydrogenated to H2CO, H3CO and H3COH. CO is the main side product of CO2 hydrogenation on the Pd(111) surface with an activation barrier of 1.09 eV. The hydrogenation of HCO species with the surface H atom to form H2CO plays as the rate determining step for CO2 hydrogenation to methanol with the barrier of 0.91 eV. Our calculated results are favorable for the understanding of the mechanism of CO2 conversion on not only Pd-based catalysts but also Pd modified catalysts. The mechanism of methanol synthesis from the hydrogenation of CO2 on the Pd(111) surface was studied using density functional theory calculations.

A zirconium/nickel-mediated one-pot synthesis of ketones is reported. In the presence of Zn or Mn, Cp2 ZrCl2 was found to dramatically accelerate the coupling and suppress side product formation via an I→SPy displacement at the same time. Unlike Zn/Pd- and Fe/Cu-mediated one-pot ketone syntheses, the new method is effective for nucleophiles bearing OR or equivalent functional groups at the α-position. A mechanism comprising a nickel catalytic cycle, a zirconium catalytic cycle, and Zr→Ni transmetalation is proposed, and Cp2 ZrCl2 and/or low-valent Zr species are suggested to play crucial dual roles.

Currently, industrial production of isocyanates, or diisocyanates in particular, has been exclusively based on phosgene processes. Phosgene is extremely toxic and large amounts of corrosive HCl are produced as a side product. In the view of environment protection and society safety, development of non-phosgene processes for isocyanates production will be highly desired, and this should be one of the most important missions for green chemistry and catalysis. In this review, efforts for development of non-phosgene method for syntheses of isocyanates, i.e., catalytic syntheses of N-substituted carbamates from nitro- or amino-compounds with CO, dimethyl carbonate (DMC), urea and even CO2 etc. as carbonyl sources, then thermal cracking of N-substituted carbamates to afford corresponding isocyanates, are summarized, and a brief prospect for non-phosgene syntheses of isocyanates is also addressed.

The energy efficiency of dividing wall column (DWC) can be further improved by the vapor recompression (VRC), but large temperature difference between overhead and bottom of the DWC hindered their combination. Meanwhile, it is difficult to choose suitable side heat exchanger position in the DWC. In this paper, we provided a direct method to design the configurations that the VRC assisted DWC at the side product stage. The Column Grand Composite Curve (CGCC) profiles were used to determine the type of phase withdrawn from the side product stage. In the CGCC profiles, if the side product stage was located in the side reboiler region, the vapor should be withdrawn from the side product stage, the SCVRC-DWC and IR-SRVRC-DWC configurations can be achieved. If the side product stage was located in the side condenser region, the liquid should be withdrawn from the side product stage, the SRVRC-DWC and the IC-SRVRC-DWC configuration can be achieved. Three separation cases with different ESI values were simulated and the results inferred that the proposed configurations had high energy efficiency when enough vapor or liquid flow can be withdrawn from the side product stage.

Reactions of ZnI2 L2 (where L=[HC(PPh2 NPh)]- ) with solutions of the Zintl phase K4 Ge9 in liquid ammonia lead to retention of the Zn-Zn bond and formation of the anion [(η4 -Ge9 )Zn-Zn(η4 -Ge9 )]6- , representing the first complex with a Zn-Zn unit carrying two cluster entities. The trimeric anion [(η4 -Ge9 )Zn{μ2 (η1 :η1 Ge9 )}Zn(η4 -Ge9 )]8- forms as a side product, indicating that oxidation reactions also take place. The reaction of Zn2 Cp*2 (Cp*=1,2,3,4,5-pentamethylcyclopentadienyl) with K4 Ge9 in ethylenediamine yielded the linear polymeric unit 1∞ {[Zn[μ2 (η4 :η1 Ge9 )]}2- with the first head-to-tail arrangement of ten-atom closo-clusters. All anions were obtained and structurally characterized as [A(2.2.2-crypt)]+ salts (A=K, Rb). Copious computational analyses at a DFT-PBE0/def2-TZVPP/PCM level of theory confirm the experimental structures and support the stability of the two hypothetical ten vertex cluster fragments closo-[Ge9 Zn]2- and (paramagnetic) [Ge9 Zn]3- .

Low concentrations of nitrogen dioxide, which arises as a side product from a range of industrial processes, can effectively be recycled through the diazotization of anilines. The studies reported herein now demonstrate that the removal of nitrogen dioxide from gas streams is even more effective when hydrophilic anilines are used as starting materials. The diazonium salts, which are obtained in this way in up to quantitative yields, can directly be employed in azo coupling reactions, thus opening up an attractive route to the industrially important group of azo compounds.

The synthesis and physicochemical properties of 2,2-difluoro-4,6-bis(2-pyridyl)-1,3-dihydro-1,3,5,2-triazaborinine (F2-Py2BTA) and 2,2-difluoro-4,6-bis(2-pyrimidinyl)-1,3-dihydro-1,3,5,2-triazaborinine (F2-Pm2BTA), prepared from their respective N-imidoylamidines, are presented. In addition, the preparation and characterization of the Lewis acid–base adduct of pyrimidine-2-carboximidamide trifluoroborane (PmAmBF3), which forms as a side product in the reaction with N-2-pyrimidylimidoyl-2-pyrimidylamidine, is also described.

Bioorthogonal chemistry holds great potential to generate difficult‐to‐access protein–protein conjugate architectures. Current applications are hampered by challenging protein expression systems, slow conjugation chemistry, use of undesirable catalysts, or often do not result in quantitative product formation. Here we present a highly efficient technology for protein functionalization with commonly used bioorthogonal motifs for Diels–Alder cycloaddition with inverse electron demand (DAinv). With the aim of precisely generating branched protein chimeras, we systematically assessed the reactivity, stability and side product formation of various bioorthogonal chemistries directly at the protein level. We demonstrate the efficiency and versatility of our conjugation platform using different functional proteins and the therapeutic antibody trastuzumab. This technology enables fast and routine access to tailored and hitherto inaccessible protein chimeras useful for a variety of scientific disciplines. We expect our work to substantially enhance antibody applications such as immunodetection and protein toxin‐based targeted cancer therapies., A highly efficient method for protein functionalization with commonly used bioorthogonal motifs for Diels–Alder cycloaddition with inverse electron demand (DAinv) is presented. This technology enables fast and routine access to tailored and hitherto inaccessible protein chimeras.

A software update solving the Bethe-Salpeter equation (BSE) is reported for the ESCF module of the TURBOMOLE program for the theoretical description of electronically excited states of atoms and molecules. A resolution-of-the-identity (RI) approximation is used for all two-electron electron-repulsion integrals that are required for solving the equation. Symmetry is utilized for the point group D2h and its subgroups, and the BSE approach can be applied in either a spin-restricted or a spin-unrestricted Kohn-Sham formalism. Triplet as well as singlet excited states of closed-shell atoms and molecules can be treated in the spin-restricted formalism. As a side product, the present software update also allows for the application of the RI approximation to the Hartree-Fock exchange contribution that occurs when a hybrid functional is used in time-dependent density-functional theory. © 2016 Wiley Periodicals, Inc.

The one-pot reaction of propiophenone with heteroaromatic, aliphatic, and unsaturated aldehydes in the presence of metal halides furnishes racemic tetrahydro-2H-pyran-2,4-diols in a highly diastereo-selective manner. The mechanism for the stereoselective product formation as well as the surprising formation of a side product was explained on the basis of DFT computations.

Factors leading to the formation of a hexahydroaporphine-like cyclizing side product were studied systematically for the first time and the ratio of this side product was controlled effectively. To understand better the electronic effect of substrates on the formation of side products, different 1-benzyloctahydroisoquinolines with substituted groups on nitrogen or benzene ring were compared. A plausible mechanism of cyclizing reaction was proposed, and key intermediates as well as transition states were analyzed using DFT calculations.

The LDA-induced coupling of 2′,3′,5′-O-protected uridine with diethyl chlorophosphate, during the synthesis of 6-phosphonouridine, is accompanied by the formation of an unexpected side product. LDA adds slowly to the C4 position of the 2′,3′,5′-O-protected uridine after the initial reaction with diethyl chlorophosphate. The presence of the phosphorochloridate facilitates the side reaction. This observation accounts for the previously reported low yield when conducting the coupling reaction for longer durations and suggests a new route for the synthesis of N-alkylated 6-phosphonocytidine analogues.

All roads lead to Rome: The biosynthesis of the leporins in Aspergillus sp. involves an unprecedented pericyclic reaction cascade. The enzyme LepI directs the periselectivity of a [4+2] cycloaddition towards a hetero-Diels-Alder reaction outcome to give the leporin molecular scaffold. The Diels-Alder side product is morphed into the leporin core structure by a LepI-catalyzed retro-Claisen rearrangement, culminating in efficient kinetic side product recycling.

Methyl adamantane-1-carboxylate and methyl (1-adamantyl)acetate react with acetonitrile in the presence of sodium hydride to give 3-(1-adamantyl)-3-oxopropanenitrile and 4-(1-adamantyl)-3-oxobutanenitrile, respectively. Reaction involving methyl (1-adamantyl)-acetate produces also 2-(1-adamantyl)-N-(E-1-cyanoprop-1-ene-2-yl)acetamide; the structure of this side product was established by X-ray diffraction analysis.

Heterocyclic azo compounds, prepared from corresponding amines in one step, are used as effective oxidants for the conversion of thiols into symmetrical disulfides in high yields. Among the studied azo compounds, 4,4′-azopyridine was found to be very efficient for the odorless conversion of alkyl halides into disulfides in the presence of thiourea. An attractive feature of this azo compound is that its obtained solid side product hydrazine is easily separated by filtration and can be recycled to its azo compound for further use.

We report the first cationic gold(i)-catalyzed one-pot reaction of amide, aldehyde and alkyne followed by cyclization, to successfully access highly substituted oxazoles derivatives in good yields., We report the first cationic gold(i)-catalyzed one-pot reaction of amide, alkyne and aldehyde followed by cyclization, to successfully access highly substituted oxazoles derivatives in good yields. A single catalyst allows the occurring of this multi-step reaction atom- and step-economically, with water as the only theoretical side product.

Acid-catalyzed formation of the peroxyacetal of cyclohexanone bis-hydroperoxide and a triterpene ketone synthesized for the first time 19β,28-epoxy-28-oxo-18α-olean-3-spiro-6′-(1′,2′,4′,5′-tetraoxacyclohexane)-3′-spirocyclohexane, the structure of which was confirmed by NMR spectroscopy and an x-ray crystal structure analysis. 19β,28-Epoxy-28-oxo-18α-olean-1-en-3-one was formed as a side product during oxidative dehydration of 28-oxoallobetulone.

Current production of diosgenin mainly depends on the acid hydrolysis of steroidal saponins from Dioscorea plants, and, in China especially, Dioscorea zingiberensis C. H. Wright (DZW) is used. The experimental results we obtained demonstrated that furostanol saponins, as the main constituents in DZW, were prone to generate 25-spirosta-3,5-diene as side product during the acid hydrolysis process, while spirostanol saponins hardly generated 25-spirosta-3,5-diene. This 25-spirosta-3,5-diene was the key reason leading to the low yield of diosgenin from DZW by acid hydrolysis. Effective conversion of furostanol saponins into spirostanol saponins can avoid the generation of 25-spirosta-3,5-diene so as to increase the yield of diosgenin, suggesting the importance of this preliminary conversion for improving the yield of diosgenin from DZW by acid hydrolysis. The conversion of furostanol saponins into spirostanol saponins can be performed by either enzymatic hydrolysis or spontaneous fermentation, whereas enzymatic hydrolysis is more controllable compared with spontaneous fermentation.

A new natural surface modified nanoclinoptilolite (NCP) was prepared and applied as an efficient catalyst for the cyclotrimerization of acetophenones to obtain 1,3,5-triarylbenzenes. The results showed that the efficiency of this catalytic system was enhanced due to the surface modification by hexadecyltrimethylammonium bromide (HDTMA-Br). This proposed protocol brings about significant economic and environmental advantages, such as operational simplicity, short reaction time, mild reaction conditions, good reaction yield, and high recyclability of the catalyst. Furthermore, the only side product of the reaction is water, which makes this methodology an environmentally friendly process.

Nano-Fe3O4 particles were used as a green and heterogeneous catalyst for Beckmann rearrangement under ultrasound irradiation and protic solvent condition in excellent yields. The advantage of this method was simple, inexpensive, easy work-up procedure, suppression of any side product.

The synthesis of new diporphyrinylamines is described. In particular, the possibility to use the Buchwald or Ullmann amination reactions to obtain these compounds is detailed. Attempts to obtain symmetrical diporphyrinylamines linked by a tertiary amine are exposed and the obtention as side-product of an unexpected unsymmetrical porphyrin dimer with a meso–β linkage is described.

Glycosylation of 3α-acetoxy-12β,25-dihydroxy-20S,24R-epoxydammarane (2) by 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosylbromide (5) in the presence of Hg(CN)2 in nitromethane at 22°C produced the acetylated 12,25-di-O-β-D-glucopyranoside of 3α,12β,25-trihydroxy-20S,24R-epoxydammarane (6) and also formed the side product 3α-acetoxy-12β-(2′,3′,4′,6′-tetra-O-acetyl-β-D-glucopyranosyloxy)-24-cyano-20S,24S-epoxydammarane (8). Condensation of 3α,12β-diacetoxy-25-hydroxy-20S,24R-epoxydammarane (3) with glycosyl donor (5) under the same conditions gave the hexaacetate of the 25-O-β-D-glucopyranoside of 3α,12β,25-trihydroxy-20S,24R-epoxydammarane and also formed a mixture of C-24-epimers (1:1) of 3α,12β-diacetoxy-24-cyano-20S,24ξ-epoxydammarane (10a,b).

Sulfuric-acid-promoted tandem reaction of phenols with acetophenones under solvent- and metal-free conditions has been developed, which afforded functional 4H-chromenes in good yields with water as the side product. Sulfuric acid appeared to serve the dual role of an efficient promoter and a suitable dehydrating agent.

C-, N-, and/or O-methylation products were generated from 11H-isoindolo[2,1-a]quinazoline-5-one upon treatment with NaH followed by iodomethane under air, and possible recrystallization from methanol. Two products were fully characterized by NMR and X-ray diffraction analysis. In accordance with the HSAB principle, this soft methylating agent (MeI) leads mainly to the C,C-dimethylated product 11,11-dimethyl-11H-isoindolo[2,1-a]quinazoline-5-one, which was previously not observed, beside the N-methylated product, in a procedure using methyl tosylate as a hard methylating agent of the same substrate in the initial absence of a base. A mechanism is finally proposed for the formation of methyl 2-(3-methyl-4-oxo-3,4-dihydroquinazolin-2-yl)benzoate as an oxidation side product.

Condensation of separately obtained C1–C9 and C10–C21 chiral blocks under Yamaguchi conditions affords the corresponding ester, an acyclic precursor of an epothilone D analogue. The reaction is accompanied by the formation of a side product of acylation of the starting alcohol by the Yamaguchi reagent.

Bei der Gewinnung von Fettsauren aus Pflanzenolen, z. B. zur Herstellung von Biopolymeren, oder bei der Biodiesel- und Seifenproduktion, fallt Glycerin als Nebenprodukt an. Bei der Biokonversion dieses Rohstoffes zu 1,3-Propandiol wird der Produktionsorganismus Clostridium diolis durch Verunreinigungen im Rohglycerin gehemmt. Als inhibierende Substanzen konnten freie Fettsauren identifiziert werden. Mithilfe eines adsorptiven Aufarbeitungsverfahrens ist es gelungen, die Fettsauren zu entfernen und die Konversionseffizienz zu 1,3-Propandiol zu erhohen. During the production of fatty acids from plant oils, e. g. for the production of biopolymers or in the biodiesel and soap production, glycerol accumulates as a side product. Using this residual material with Clostridium diolis for the production of 1,3-propanediole is not efficient, due to inhibitory effects of impurities. Fatty acids have been identified as inhibiting substances. After removal of the residual fatty acids by pretreatment with adsorbents, it has been possible to use this glycerol with high conversion efficiency towards 1,3-propanediole.

Different approaches to brominate dialkyl isothianaphthene-5,6-dicarboxylate were tried and single crystals of target molecule and side product were obtained. A planar copolymer with the trans-ethene has been prepared, which shows good solubility in common organic solvents and broad absorption with edge to 967 nm in film.

A new functionalized SBA-15 catalyst immobilized CuI was successfully prepared, and the catalytic activity was tested in the oxidative homocoupling of terminal alkynes at the absence of base, and good to excellent yields was obtained to get 1,3-diynes without any side product formation in the solution of DMSO. Moreover, the system also allowed the synthesis of unsymmetric 1,3-diynes by cross-coupling of two different terminal alkynes. Finally, the catalyst could be reused for several times without a significant loss of activity.

The synergistic effects of multiple additives (water and acetic acid) on the asymmetric Michael addition of acetone to nitrostyrene catalyzed by primary amine-thioureas (PAT) were precisely determined. Acetic acid facilitates hydrolysis of the imine intermediates, thus leading to catalytic behavior, and minimizes the formation of the double addition side product. In contrast, water slows down the reaction but minimizes catalyst deactivation, eventually leading to higher final yields.

The reactivity of two stable Si(6)R(6) clusters (4 and 5, R = 2,4,6-(i)Pr(3)C(6)H(2)) with unsymmetrical substitution patterns (including Si, SiR, and SiR(2) vertices) is reported. In order to account for the importance of such clusters as model systems for transient intermediates in the deposition of elemental silicon, we here propose the term "siliconoids" for silicon clusters with unsaturated valencies. With the hexasilaprismane 8a, a saturated-i.e., non-siliconoid-Si(6)R(6) isomer is accessible from a suitable Si(3) precursor. Thermal redistribution of the substituents converts 1,1,2-trichlorocyclotrisilane 6 into the corresponding 1,2,3-derivative 7 prior to the requisite reductive coupling step leading to 8a. On the other hand, a stable expanded Si(11)-siliconoid 9 was isolated as a minor side product of the thermal isomerization of 4 to 5, thus providing a first example of siliconoid cluster expansion in the condensed phase. In the solid-state structure, the two unsubstituted vertices of 9 strongly interact in a staggered propellane-like fashion. Oxidative cluster contraction of a siliconoid scaffold is observed upon treatment of siliconoid 5 with a large excess of iodine in refluxing toluene, thus providing access to a highly functionalized hexaiodocyclopentasilane 11 in high yield. Conversely, chlorination of the isomeric 4 with BiCl(3) as a mild source of Cl(2) results in a complex mixture of products from chlorination of the unsubstituted vertices as well as σ-bonds of the cluster framework of 4. The main product, 1,2-dichlorotricyclo[2.2.0.0(2,5)]hexasilane 12, undergoes thermal cluster contraction to give tricyclo[2.1.0.0(2,5)]pentasilane 14 with an exohedral chlorosilyl group.

We describe a practical, multigram synthesis of (2Z,6Z,10Z,14Z,18E,22E)-3,7,11,15,19,23,27-heptamethyl-2,6,10,14,18,22,26-octacosaheptaen-1-ol [(Z(4),E(2),ω)-heptaprenol, 4] using the nerol-derived sulfone 8 as the key intermediate. Sulfone 8 is prepared by the literature route and is converted in five additional steps (18% yield from 8) to (Z(4),E(2),ω)-heptaprenol 4. The use of Eu(hfc)(3) as an NMR shift reagent not only enabled confirmation of the structure and stereochemistry of 4, but further enabled the structural assignment to a major side product from a failed synthetic connection. The availability by this synthesis of (Z(4),E(2),ω)-heptaprenol 4 in gram quantities will enable preparative access to key reagents for the study of the biosynthesis of the bacterial cell envelope.

There is considerable current interest in coenzyme Q10 (CoQ10) from a medical perspective. CoQ10 has been shown to alleviate the side effects of statin drugs, for instance, and so there is a push to find naturally high producers of the compound. Sporidiobolus johnsonii (S. johnsonii) has been reported to produce CoQ10 in studies that used only standards on thin-layer chromatography (TLC) and also suggested the production of coenzyme Q9 (CoQ9). This work set out to verify CoQ9/CoQ10 production in S. johnsonii and quantify as appropriate. We show that S. johnsonii produces CoQ10 but found no evidence for CoQ9 biosynthesis. The specific production of CoQ10 was noted at 10 mg/g dry cell weight (DCW) in media supplemented with 4-hydroxybenzoic acid (HBA). This makes S. johnsonii a naturally high CoQ10 producer. New methods for extraction and purification of CoQ10 are also discussed, and identification of a closely eluting side product under normal phase isolation is reported.

Reductive amination of aromatic aldehydes using NaBH4 and isoxazole amines is carried out in a Bronsted acidic ionic liquid 1-methylimidazolium tetrafluoroborate [(HMIm)BF4]. The ionic liquid plays dual roles of solvent as well as catalyst for the efficient transformation of aromatic aldehydes to heterocyclic substituted amines in excellent yields without any undesired side product formation. The newly synthesized compounds (3, 6 and 7) were characterized by IR, 1H NMR and mass spectral techniques.

The synthesis of heterobimetallic cluster with the Al-S-M (M = Cu and Ag) structural unit has been realized for the first time by the reaction of aluminum-dithiol LAl(SH)2 (L = HC[C(Me)N(Ar)]2, Ar = 2,6-iPr2C6H3) with (MesCu)4 and (MesAg)4 (Mes = 2,4,6-Me3C6H2), respectively. The isolated clusters exhibit core structures of Al2Cu4S4 and Al4Ag8S8, respectively. During the formation of the [LAl(SAg)2]4, a side product of LAlS6 is formed. However, the reaction of LAl(SH)2 with excess of sulfur and (MesAg)4 resulted in the formation of LAlS4 as the only product soluble in organic solvents. Both of them represent rare examples of aluminum polysulfides. All compounds were characterized by spectroscopic methods and single crystal X-ray diffraction studies.

A simple and efficient protocol for CuI-catalyzed oxidative homocoupling reaction of terminal alkynes to symmetrical 1,4-disubstituted 1,3-diynes was reported. The reaction can be carried out in the open air, using NaOAc as a base in the absence of any other additives. A variety of terminal alkynes were converted to the corresponding 1.3-diynes in good to excellent yields without any side product formation. Copyright © 2010 John Wiley & Sons, Ltd.

A novel two-step route for the synthesis of RhFe3N is presented that yields the target material with a significantly improved phase purity. Except from Fe0.5Rh0.5, the absence of other side product...

An efficient nucleophilic substitution of Baylis–Hillman adducts with alcohols catalysed by 10 mol% BiCl3, affords functionalised ethers. Water was the only side product.

Efficient, scalable cobalt-catalyzed redox-neutral [4+2] annulation of readily available oximes and alkyne is reported. The developed synthetic methodology is widely applicable and tolerates various functional groups including heterocycles. A stable Cp*Co(III) neutral complex is employed as the catalyst for this redox-neutral [4+2] annulation reaction, which progresses smoothly by way of a reversible cyclometallation without any external oxidizing agent, and produces only water as the side product.

A simple, eco-sustainable method for theN-(9-fluorenylmethoxycarbonyl) (N-Fmoc) protection of various structurally amines under ultrasonic irradiation is reported. The corresponding N-Fmoc derivatives were obtained in good to excellent yields within short reaction time. The reaction proceeds without the formation of any side product. Mildness, efficiency and easier work are the main advantages of this new protocol.

Simple Bronsted acids such as p-toluenesulfonic acid monohydrate (PTS) or polymer-bound p-toluenesulfonic acid efficiently catalyze the direct nucleophilic substitution of the hydroxy group of allylic and benzylic alcohols with a large variety of carbon- and heteroatom-centered nucleophiles. Reaction conditions are mild, the process is conducted under an atmosphere of air without the need for dried solvents, and water is the only side product of the reaction.

Palladium-catalyzed carbonylative cross-coupling reaction of ethynylstibane (PhSbPh(2)) and aryl iodides (Ar-I) is described. The reaction of the stibanes and the halides under 1 atm of carbon monoxide in N,N-dimethylacetamide using a combination of 5 mol% Pd(OAc)(2) and 4 equivalents (20 mol%) of PPh(3) brought about carbonylative cross-coupling reaction to afford arylethynylketones [ArC(O)Ph] in good yields along with a small amount of directly coupled products, aryl acetylens (ArPh). Formation of the side product was completely suppressed by conducting the reaction under high CO pressure (20 atm) conditions. The present method provides a variety of carbonylated products in good yield even with electron-deficient aryl iodides which usually give inferior results due to their tendency to undergo decarbonylation in the cross-coupling reaction of ethynylstibanes and acyl halides.

A layered potassium cobalt oxide of K x CoO 2 ( x = 0.55) was prepared by solid-state reaction between KO 2 and Co 3 O 4 . We explored soft-chemical reactivities of this material in treatments with acid or bromine solutions by following compositional and structural changes by X-ray diffraction and chemical analysis. The acid treatment promoted K + /H 3 O + exchange but concurrently induced the formation of CoOOH as a side product. The compound underwent oxidative deintercalation of K + upon the action of Br 2 , which was accompanied by hydration. Reinsertion of alkali metal ions into the resulting Br 2 -treated sample could be attained by the treatment with corresponding hydroxide solutions.

The title compound, isobutyltin(IV) dichloride hydroxide N,N-dimethylformamide solvate {(iBuSnCl 2 (OH) (DMF)) 2 }, an accidental side product from the reaction of isobutyltin(IV) trichloride with moisture in N,N-dimethyl- formamide, exhibits structural features similar to those of the corresponding hydrates of monoorganotin(IV) dihal- ide hydroxides characterized by a central four-membered rhombic Sn-O ring and tin atoms with a distorted octahe- dral coordination.

Reversible modification of iron-sulfur clusters by nitric oxide acts as a genetic switch in a group of regulatory proteins. While the conversion of [Fe-S] clusters to iron-nitrosyls has been widely studied in the past, little is known about the reverse process, the repair of [Fe-S] clusters. Reported here is a system in which a mononitrosyl iron complex (MNIC), (PPN)[Fe(S(t)Bu)3(NO)] (1), is converted to a [2Fe-2S] cluster, (PPN)2[Fe2S2(SCH2CH2C(O)OMe)4] (2). This conversion requires only the addition of a cysteine analogue, 3-mercaptomethylpropionate (MMP), at room temperature without the need for any other reagents. The identity of 2 was confirmed spectroscopically, chemically, crystallographically, and analytically. Mass spectrometry and (34)S labeling studies support that the bridging sulfides in 2 derive from the added MMP, the cysteine analogue. The NO lost during the conversion of 1 to 2 is trapped in a dinitrosyl iron side product, (PPN)[Fe(SCH2CH2C(O)OMe)2(NO)2] (4). The present system implies that MNICs are likely intermediates in the repair of NO-damaged [2Fe-2S] clusters and that cysteine is a viable molecule responsible for the destabilization of MINCs and the formation of [2Fe-2S] clusters.