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Abstract Over the past years, significant effort has been dedicated to synthesizing low-shrinking formulations, however, development of dental composites with low volumetric shrinkage continues to be challenging. The purpose of this study was to synthesize a bisphenol allylic derivate (BPhADAC) and evaluate its inclusion in the formulation of a photopolymerizable dental composite resin, as a BisGMA diluent. Experimental (BisGMA/ BPhADAC) and control (BisGMA/TEGDMA) photopolymerizable composites were prepared. Double bond conversion, polymerization kinetics, volumetric shrinkage, water sorption, solubility, and flexural properties were investigated. The experimental composite showed higher degree of conversion values, less volumetric shrinkage and less water sorption than the control composite (p < 0.05). In addition, flexural strength between the materials was found to be similar. The overall properties prove that the allylic monomer BPhADAC could be potentially useful in the formulation of low-shrinking dental composite resins. Graphical abstract fx1 [ABSTRACT FROM AUTHOR]

A barium-catalyzed C-OH/P-H dehydrative cross-coupling protocol for the construction of C-P bonds was developed. This reaction was performed in an environmentally benign manner with water as the only by-product. A variety of allylic phosphorus compounds can be isolated in good to excellent yields. [ABSTRACT FROM AUTHOR]

Kappa (κ) opioid receptor selective antagonists are useful pharmacological tools in studying κ opioid receptors and have potential to be used as therapeutic agents for the treatment of a variety of diseases including mood disorders and drug addiction. Arodyn (Ac[Phe 1–3 ,Arg 4 , d -Ala 8 ]Dyn A-(1–11)NH 2 ) is a linear acetylated dynorphin A (Dyn A) analog that is a potent and selective κ opioid receptor antagonist (Bennett et al. J Med Chem 2002;45:5617–5619) and prevents stress-induced reinstatement of cocaine-seeking behavior following central administration (Carey et al. Eur J Pharmacol 2007;569:84–89). To restrict its conformational mobility, explore possible bioactive conformations and potentially increase its metabolic stability we synthesized cyclic arodyn analogs on solid phase utilizing a novel ring-closing metathesis (RCM) reaction involving allyl-protected Tyr (Tyr(All)) residues. This approach preserves the aromatic functionality and directly constrains the side chains of one or more of the Phe residues. The novel cyclic arodyn analog 4 cyclized between Tyr(All) residues incorporated in positions 2 and 3 exhibited potent κ opioid receptor antagonism in the [ 35 S]GTPγS assay (K B  = 3.2 nM) similar to arodyn. Analog 3 cyclized between Tyr(All) residues in positions 1 and 2 also exhibited nanomolar κ opioid receptor antagonist potency (K B  = 27.5 nM) in this assay. These are the first opioid peptides cyclized via RCM involving aromatic residues, and given their promising pharmacological activity represent novel lead peptides for further exploration. [ABSTRACT FROM AUTHOR]

ABSTRACT: A novel allyl compound containing liquid crystalline structure, i.e., 4,4’‐bis(4‐allyloxy benzoic acid) phenyl ester (BAOBE), was synthesized. The chemical structure of BAOBE was characterized by Fourier transform infrared (FTIR) spectroscopy and 1H NMR spectra, and the liquid crystalline properties were confirmed by polarized optical microscopy (POM). Besides, a series of modified bismaleimide (BMI) resins were prepared based on N,N′‐4,4′‐bismaleimidodiphenylmethylene (BDM), BAOBE, and O,O’‐diallyl bisphenol A (DABPA). The results of thermogravimetric analysis (TGA) indicate that the modified resins have excellent thermal stability with the highest temperatures for 5% weight loss above 438°C. The results of dynamic mechanical analysis (DMA) suggest that the glass transition temperature (Tg) of the modified resins are above 280°C. Besides, the introduction of BAOBE leads to a significant improvement in the flexural and impact properties of the modified BMI resins. Compared with the resin with only DABPA as a modifier, the highest flexural and impact strength can reach 156.2 MPa and 15.6 kJ/m2, increased by 19.2% and 90.2%, respectively. [ABSTRACT FROM AUTHOR]

An efficient methodology for the synthesis of vinyl-, allyl-, and (E)-2-boryl allylboronates from propargylic alcohols via Cu-catalyzed borylation under mild conditions is reported. In the presence of commercially available Cu(OAc)2 or Cu(acac)2 and Xantphos, the reaction affords the desired products in up to 92% yield with a broad substrate scope (43 examples). Isolation of an allenyl boronate as the reaction intermediate suggests that an insertion-elimination-type reaction, followed by borylcupration, is involved in the borylation of propargylic alcohols. [ABSTRACT FROM AUTHOR]

The rosin molecules can improve the adhesion and mechanical properties of polymers. It may be introduced either directly or via active functional groups. The focus of this work has been to develop a new method for creating such active functional groups connected to the acrylpimarate molecule by a microwave irradiation and phase-transfer catalytic reaction with allyl chloride. The synthesized monomer was then polymerized under ultraviolet (UV) irradiation. A new polymerization monomer with two functional groups (two allyl groups) has been synthesized through Diels-Alder reaction using levopimaric acid (an important component of rosin) as raw material under microwave irradiation. The yield and gas chromatography on content of the allyl acrylpimarate monomer were 92.2% and 98.6%, respectively. Due to the steric hindrance in the original rosin molecules, two major allyl acrylpimarate isomers in a 1:4 ratio were observed in the monomeric products, as confirmed by two-dimensional nuclear magnetic resonance spectroscopy (2D NMR). UV-curing reaction of the synthesized monomer confirmed that its two functional groups led to a novel polymerization pathway compared with that of the monomer bearing only one allyl group. Conversion of the monomer reached 90% by using Michlers ketone as a photoinitiator. The cured film was composed of a three-dimensional cross-linked polymer due to the bifunctional monomer, and showed good performance in terms of thermal stability, hardness, and chemical resistance. [ABSTRACT FROM AUTHOR]

Cobalt(II)-based metalloradical catalysis has been successfully applied to radical bicyclization of allyl azidoformates to construct aziridine/oxazolidinone-fused bicyclic structures. The Co(II) complex of D 2-symmetric chiral amidoporphyrin 3,5-Di t Bu-QingPhyrin has been identified as an effective metalloradical catalyst for the intramolecular radical aziridination of this type of carbonyl azides, allowing for high-yielding formation of synthetically useful chiral [3.1.0]-bicyclic aziridines with high diastereo- and enantioselectivity. [ABSTRACT FROM AUTHOR]

Allyl isothiocyanate (AITC), present in Wasabia japonica (wasabi), is an aliphatic isothiocyanate derived from the precursor sinigrin, which is a glucosinolate present in vegetables of the Brassica family. Traditionally, it has been used to treat rheumatic arthralgia, blood circulation, and pain. This study focuses on its anti-apoptotic activity through the regulation of lipopolysaccharide (LPS)-induced neuroinflammation. Furthermore, we assessed its neuroprotective efficacy, which it achieves through the upregulation of nerve growth factor (NGF) production. Pretreatment with AITC significantly inhibited inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression, decreased tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), prostaglandin E2 (PGE2), and nitric oxide (NO) production in activated microglia, and increased the nerve growth factor (NGF) and neurite outgrowth in neuroblastoma cells. AITC inhibited the nuclear factor (NF-κB-mediated transcription by modulating mitogen activated protein kinase (MAPK) signaling, particularly downregulating c-Jun N-terminal kinase (JNK) phosphorylation, which was followed by a reduction in the TNF-α expression in activated microglia. This promising effect of AITC in controlling JNK/NF-κB/TNF-α cross-linking maintains the Bcl-2 gene family and protects neuroblastoma cells from activated microglia-induced toxicity. These findings provide novel insights into the anti-neuroinflammatory effects of AITC on microglial cells, which may have clinical significance in neurodegeneration. [ABSTRACT FROM AUTHOR]

( E)-δ-Boryl-substituted anti-homoallylic alcohols are synthesized in a highly diastereo- and enantioselective manner from 1,1-di(boryl)alk-3-enes and aldehydes. Mechanistically, the reaction consists of 1) palladium-catalyzed double-bond transposition of the 1,1-di(boryl)alk-3-enes to 1,1-di(boryl)alk-2-enes, 2) chiral phosphoric acid catalyzed allylation of aldehydes, and 3) palladium-catalyzed geometrical isomerization from the Z to E isomer. As a result, the configurations of two chiral centers and one double bond are all controlled with high selectivity in a single reaction vessel. [ABSTRACT FROM AUTHOR]

The ball milling of beryllium chloride with two equivalents of the potassium salt of bis(1,3-trimethylsilyl)allyl anion, K[A'] (A' = [1,3-(SiMe3)2C3H3]), produces the tris(allyl)beryllate K[BeA'3] (1) rather than the expected neutral BeA'2. The same product is obtained from reaction in hexanes; in contrast, although a similar reaction conducted in Et2O was previously shown to produce the solvated species BeA'2(OEt2), it can produce 1 if the reaction time is extended (16 h). The tris(allyl)beryllate is fluxional in solution, and displays the strongly downfield 9Be NMR shift expected for a three-coordinate Be center (δ22.8 ppm). A single crystal X-ray structure reveals that the three allyl ligands are bound to beryllium in an arrangement with approximate C3 symmetry (Be-C (avg) = 1.805(10) Å), with the potassium cation engaging in cation-π interactions with the double bonds of the allyl ligands. Similar structures have previously been found in complexes of zinc and tin, i.e., M[M'A'3L] (M' = Zn, M = Li, Na, K; M' = Sn, M = K; L = thf). Density functional theory (DFT) calculations indicate that the observed C3-symmetric framework of the isolated anion ([BeA'3]-]-) is 20 kJ ⋅ mol-1 higher in energy than a C1 arrangement; the K+ counterion evidently plays a critical role in templating the final conformation. [ABSTRACT FROM AUTHOR]

The ball milling of beryllium chloride with two equivalents of the potassium salt of bis(1,3-trimethylsilyl)allyl anion, K[A'] (A' = [1,3-(SiMe3)2C3H3]), produces the tris(allyl)beryllate K[BeA'3] (1) rather than the expected neutral BeA'2. The same product is obtained from reaction in hexanes; in contrast, although a similar reaction conducted in Et2O was previously shown to produce the solvated species BeA'2(OEt2), it can produce 1 if the reaction time is extended (16 h). The tris(allyl)beryllate is fluxional in solution, and displays the strongly downfield 9Be NMR shift expected for a three-coordinate Be center (δ22.8 ppm). A single crystal X-ray structure reveals that the three allyl ligands are bound to beryllium in an arrangement with approximate C3 symmetry (Be-C (avg) = 1.805(10) Å), with the potassium cation engaging in cation-π interactions with the double bonds of the allyl ligands. Similar structures have previously been found in complexes of zinc and tin, i.e., M[M'A'3L] (M' = Zn, M = Li, Na, K; M' = Sn, M = K; L = thf). Density functional theory (DFT) calculations indicate that the observed C3-symmetric framework of the isolated anion ([BeA'3]-]-) is 20 kJ ⋅ mol-1 higher in energy than a C1 arrangement; the K+ counterion evidently plays a critical role in templating the final conformation. [ABSTRACT FROM AUTHOR]

The hydrocarboxylation of allyl cyanide with monodentate phosphine systems (Pd/triphenylphosphine and protic acid cocatalyst) gave branched 3-cyano-2-methylpropanoic acid chemo- and regioselectively, whereas with bidentate systems (Pd/bis[(2-diphenylphosphino)phenyl] ether and protic acid cocatalyst) it gave linear 4-cyanobutanoic acid chemo- and regioselectively. 3-Cyano-2-methylpropanoic acid and 4-cyanobutanoic acid were isolated in high yields as carboxylic acids and purified as benzyl esters. No isomerization of allyl cyanide to crotononitrile or its carbonylated derivatives was observed in any case. In parallel experiments, deuterocarboxylation under the same conditions gave the corresponding deuterated products, which were analyzed by MS and 2H NMR spectroscopy: only d0, d1, and d2 products were detected. Deuterium entered the β and γ-CN positions of the products but never the α position. [ABSTRACT FROM AUTHOR]

Polyetherethersulfones with double bonds inserted along the main polymer chain are synthesized by polycondensation. The glass transition is modulated by increasing the size of aromatic etherethersulfone rigid blocks and decreasing the ratio of flexible allyl segments which contain a double bond. Resulting copolymers have a Mn of up to 60 000 g mol−1, moderate polydispersity indices ( Đ or Ip) of 1.70 to 2.11, and are shown, by the presence of a single glass transition temperature in differential scanning calorimetry and by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, to be random. The glass transition of copolymers follows the Gordon-Taylor relationship. The thermal resistance of copolymers increases when decreasing the amount of the flexible segment and increasing the length of the rigid block. Chemical aging of films is investigated by immersion in bleach, which is commonly used to clean membranes. Films show high resistance to bleach, therefore making this approach relevant to membrane fabrication. [ABSTRACT FROM AUTHOR]

Exploiting catalytic carbonyl-olefin metathesis is an ongoing challenge in organic synthesis. Reported herein is an FeCl3-catalyzed ring-closing carbonyl-olefin metathesis. The protocol allows access to a range of carbo-/heterocyclic alkenes with good efficiency and excellent trans diastereoselectivity. The methodology presents one of the rare examples of catalytic ring-closing carbonyl-olefin metathesis. This process is proposed to take place by FeCl3-catalyzed oxetane formation followed by retro-ring-opening to deliver metathesis products. [ABSTRACT FROM AUTHOR]

The treatment of silylethynyloxyarenes with allylic pivalates in the presence of a palladium catalyst led to efficient C−H bond cleavage in both substrates and a novel annulation reaction to give 2,3-bismethylenechromanes. When ortho-allylated silylethynyloxybenzenes were used as the substrates, the same products were obtained. This result shows that site-selective intramolecular hydrovinylation is involved in the annulation reaction. The synthetic utility of the products was demonstrated by the construction of condensed polycycles. [ABSTRACT FROM AUTHOR]

Asymmetric methods for preparation of chiral alkynyl-containing compounds are in extremely high demand in many sectors of chemical research. In this work, we report the discovery of a general organocatalytic enantioselective alkynylation based on the idea of Si/F activation of the allylic C−F bond. This approach features reasonably broad substrate scope, functional group tolerance, and relatively neutral, mild, and operationally convenient reaction conditions; all of which bode well for the synthetic value of the discovered method. In particular, this method provides unique chiral skipped 1,4-ene-ynes having two kinds of versatile functional groups. [ABSTRACT FROM AUTHOR]

Branched allylic amines were prepared by Ir-catalyzed enantioselective allylic aminations with the bulky N-nucleophiles HN(Boc)2 and HNBn2. The products were transformed into N-protected amino aldehydes, which were either reduced or coupled diastereoselectively with organometallic compounds to give vicinal amino alcohols. A formal synthesis of the neurokinin receptor antagonist (+)-L-733060 was carried out as an application. [ABSTRACT FROM AUTHOR]

Allylic substitution reactions provide a valuable tool for the functionalization of CH acidic pronucleophiles. Often, control over the stereocenter generated at the nucleophilic reactant is still a challenge. The majority of studies that address this issue employ metal complexes with a low metal oxidation state (e.g. Pd0) to form allyl complexes through oxidative addition. In this article we describe the use of heterobimetallic PtII/PdII complexes, which probably activate the olefinic substrates through an SN2′ pathway. The reaction of α-cyanoacetates delivers linear allylation products with exclusive regioselectivity and high E/ Z-selectivity for the new C=C double bond. Although the enantioselectivities attained are moderate, they are significantly higher than with related mono-PdII or -PtII catalysts or the corresponding bis-PdII complex, which indicates cooperation of the different metals. Control experiments suggest simultaneous activation of both reaction partners. [ABSTRACT FROM AUTHOR]

Allyl, dimethylallyl, crotyl, and prenyl ethers of various aromatic ortho-hydroxy carbonyl compounds undergo a tandem sequence of Claisen rearrangement, carbonyl olefination, and cyclization upon microwave irradiation in the presence of a stabilized ylide. The products are multiply substituted 6- or 8-allylated or prenylated coumarins (2H-chromen- 2-ones). [ABSTRACT FROM AUTHOR]

2D structurally related iron(ii) coordination networks {[Fe(hbtz)2(RCN)2](ClO4)2}∞ featuring, besides tetrazol-2-yl rings in the first coordination sphere, also axially coordinated propionitrile or allyl cyanide molecules (R = C3H5–, 1; R = C2H5–, 2) were synthesized. Thermally induced spin crossover (SCO) in 1 takes place in two poorly resolved stages (T11/2↓ = T11/2↑ = 198 K, T21/2↓ = 170 K, T21/2↑ = 171 K) whereas in 2 complete and relatively gradual one step SCO (T1/2↓ = T1/2↑ = 160 K) occurs. Diversification of the SCO properties of the complexes originates from the ability of coordinated allyl cyanide in 1 to undergo conformational alterations, which is not observed for propionitrile molecules in 2. SCO in 1 is accompanied by a non-monotonic change of the contribution of allyl cyanide conformers which is related to reconstruction of the network of intermolecular contacts established between polymeric layers. The coordination network 1 exhibits extraordinary elasticity and in the second stage SCO, accompanied by conformational changes of allyl cyanide, triggers a crystallographic phase transition which leads to the formation of a superstructure. What is important, the formation of the superstructure is not caused by long range ordering of HS and LS iron(ii) ions. The structural alteration is associated with corrugation of the polymeric skeleton and disappearance of nitrile disorder. Irradiation of a single crystal of 1 at 15 K with laser light (520 nm) allowed producing a novel low temperature HS phase of 1 in which, contrary to the high temperature HS phase, disordering of anion and allyl cyanide molecules is not observed and the corrugated nature of the polymeric layer, characteristic of the LS phase, is preserved. [ABSTRACT FROM AUTHOR]

2D structurally related iron(ii) coordination networks {[Fe(hbtz)2(RCN)2](ClO4)2}∞ featuring, besides tetrazol-2-yl rings in the first coordination sphere, also axially coordinated propionitrile or allyl cyanide molecules (R = C3H5–, 1; R = C2H5–, 2) were synthesized. Thermally induced spin crossover (SCO) in 1 takes place in two poorly resolved stages (T11/2↓ = T11/2↑ = 198 K, T21/2↓ = 170 K, T21/2↑ = 171 K) whereas in 2 complete and relatively gradual one step SCO (T1/2↓ = T1/2↑ = 160 K) occurs. Diversification of the SCO properties of the complexes originates from the ability of coordinated allyl cyanide in 1 to undergo conformational alterations, which is not observed for propionitrile molecules in 2. SCO in 1 is accompanied by a non-monotonic change of the contribution of allyl cyanide conformers which is related to reconstruction of the network of intermolecular contacts established between polymeric layers. The coordination network 1 exhibits extraordinary elasticity and in the second stage SCO, accompanied by conformational changes of allyl cyanide, triggers a crystallographic phase transition which leads to the formation of a superstructure. What is important, the formation of the superstructure is not caused by long range ordering of HS and LS iron(ii) ions. The structural alteration is associated with corrugation of the polymeric skeleton and disappearance of nitrile disorder. Irradiation of a single crystal of 1 at 15 K with laser light (520 nm) allowed producing a novel low temperature HS phase of 1 in which, contrary to the high temperature HS phase, disordering of anion and allyl cyanide molecules is not observed and the corrugated nature of the polymeric layer, characteristic of the LS phase, is preserved. [ABSTRACT FROM AUTHOR]

Allyl- and propargyl-phosphorylcholines were efficiently synthesized and fully characterized. The molecular structure of allyl-phosphorylcholine was studied by single-crystal X-ray diffraction for the first time. [ABSTRACT FROM PUBLISHER]

Allylsilanes underwent sila- ene reaction with sulfur dioxide in the presence of Lewis acid catalysts. The obtained Vogel’s silyl sulfinates were found to act as sulfinyl transfer agents in reactions with aryl, heteroaryl, alkyl, and allyl Grignard reagents proceeding with the expulsion of the trialkylsilyloxy group to give allyl sulfoxides in up to 83% yield. The nucleophilic attack of Grignard reagents was accelerated in toluene and in the presence of LiCl or ZnCl 2 as Lewis acidic additives. The developed method allows the transformation of allylsilanes into allyl sulfoxides. [ABSTRACT FROM AUTHOR]

Control of 1,2- and 1,4-addition of substituted phenols to allylic oxides is achieved by intercepting palladium π-allyl complexes. The interconversion of palladium complexes results in the total synthesis of MK 7607, cyathiformine B type, streptol, and a new cyclitol. [ABSTRACT FROM AUTHOR]

Two allyl-containing bifunctional benzoxazines ( o AP-hda and o AP-dds) were synthesized from o -allylphenol, formaldehyde, and two diamines [1,6-hexamethylenediamine (HDA) and 4,4′-diaminodiphenyl sulfone (DDS)]. The chemical structures of o AP-hda and o AP-dds were confirmed by 1 H and 13 C nuclear magnetic resonance (NMR) spectroscopy and Fourier transform infrared (FTIR) spectroscopy. The reactivity of HDA is higher than that of DDS in the synthetic reaction of benzoxazines, and the polymerization temperature of o AP-hda is lower than that of o AP-dds. The structure changes from benzoxazines to their corresponding polybenzoxazines [Poly( o AP-hda) and Poly( o AP-dds)] were studied by FTIR and solid state 13 C NMR. The dynamic mechanical properties and thermal stabilities of Poly( o AP-hda) and Poly( o AP-dds) were studied by dynamic mechanical analysis and thermogravimetry, respectively. The storage moduli in the glassy state are 1.44 and 3.18 GPa for Poly( o AP-hda) and Poly( o AP-dds), respectively, and the glass transition temperatures are 87 and 193 °C, respectively. The thermal stability of Poly( o AP-dds) is much higher than that of Poly( o AP-hda). [ABSTRACT FROM AUTHOR]

We report here the results obtained in the study of organocatalytic asymmetric Diels–Alder reactions to optimize the synthesis of stereo defined allyltin derivatives using ( Z )-2-(1-cyclohexenyl)-1-ethenyl(trineophyl)stannane ( 1 ) as diene and substituted dienophiles in the presence of (4R,5R)-α,α,α′,α′-tetraphenyl-1,3-dioxolane-4,5-dimethanol (TADDOL, I ) and analogs (4R,5R)-α,α,α′,α′-tetra(1-naphtyl)-1,3-dioxolane-4,5-dimethanol ( II ) and (4R,5R)-α,α,α′,α′-tetra(9-phenantryl)1,3-dioxolane-4,5-dimethanol ( III ) as chiral catalysts to enhance stereoselectivity through hydrogen bond activation of the dienophile. Catalyst II provided excellent results and ultrasonic radiation at low temperature showed the shorter reaction times. [ABSTRACT FROM AUTHOR]

Gas-phase carbon-carbon bond forming reactions, catalyzed by group 10 metal acetate cations [(phen)M(O2CCH3)]+ (where M = Ni, Pd or Pt) formed via electrospray ionization of metal acetate complexes [(phen)M(O2CCH3)2], were examined using an ion trap mass spectrometer and density functional theory (DFT) calculations. In step 1 of the catalytic cycle, collision induced dissociation (CID) of [(phen)M(O2CCH3)]+ yields the organometallic complex, [(phen)M(CH3)]+, via decarboxylation. [(phen)M(CH3)]+ reacts with allyl acetate via three competing reactions, with reactivity orders (% reaction efficiencies) established via kinetic modeling. In step 2a, allylic alkylation occurs to give 1-butene and reform metal acetate, [(phen)M(O2CCH3)]+, with Ni (36%) > Pd (28%) > Pt (2%). Adduct formation, [(phen)M(C6H11O2)]+, occurs with Pt (24%) > Pd (21%) > Ni(11%). The major losses upon CID on the adduct, [(phen)M(C6H11O2)]+, are 1-butene for M = Ni and Pd and methane for Pt. Loss of methane only occurs for Pt (10%) to give [(phen)Pt(C5H7O2)]+. The sequences of steps 1 and 2a close a catalytic cycle for decarboxylative carbon-carbon bond coupling. DFT calculations suggest that carbon-carbon bond formation occurs via alkene insertion as the initial step for all three metals, without involving higher oxidation states for the metal centers. [ABSTRACT FROM AUTHOR]

Total synthesis of anticonvulsant amino acid, lacosamide, is reported. The key step is stereospecific allyl cyanate-to-isocyanate rearrangement, which proceeds with chirality transfer. The enantiopure starting material for the rearrangement step was accessed from ethyl I-lactate. [ABSTRACT FROM AUTHOR]

Rapid and efficient deallylation of allyl phenyl ethers by molecular iodine (20 mol%) in polyethylene glycol-400 at 60 °C has been reported. This method has short reaction time, readily available catalyst, and reuse of reaction medium with good yield. The utility of this methodology has been extended to flavone synthesis. [Supplementary materials are available for this article. Go to the publisher's online edition ofSynthetic Communications®for the following free supplemental resource(s): Full experimental and spectral details.] [ABSTRACT FROM AUTHOR]

The iodine-induced of 2′-hydroxychalcones provides a simple, highly efficient approach to various hydroxy flavones and analogues. This process is run under mild conditions, tolerates various functional groups, and provides hydroxy flavones in good to excellent yield. The allyl-protected acetophenones and benzaldehydes were smoothly deallylated under similar conditions. [ABSTRACT FROM AUTHOR]

The first chemical synthesis of the 3-deazaspongosine nucleoside is described, starting from commercially available 4-amino-2,6-dichloropyridine. The key step is the introduction of required functional groups at the 2 and 6 positions of the 4-amino-3-nitropyridine without any conflict in the synthesis of nucleobase. Regioselective nucleophilic substitution with allyl alkoxide at the 2 position of 4-amino-2,6-dimethoxypyridine, followed by sequential deallylation and chlorination led to the desired 2-chloro derivative. Ring closure of the 3,4-diaminopyridine and stereoselective glycosylation of the imidazo[4,5- c]pyridine with tetraacetate-protected ribofuranose gave only the N9-β-isomer. A final nucleophilic displacement of the 6-chloride by hydrazine followed by reduction with Raney Nickel gave the desired 3-deazaspongosine. [ABSTRACT FROM AUTHOR]

Quantum chemical calculations using DFT and ab initio methods were carried out on the structures of the title compounds. The nature of the bonding was investigated with an energy decomposition analysis. The calculations predict that the planar C2 v allyl structures of the neutral and charged heavier group-14 homologues [H2 E- E(H)- EH2]-, ·,+ ( E = Si - Sn) are no minima on the potential energy surface. Energy minima for allyl-type structures of the latter systems possess Cs symmetry and pyramidal EH2 groups. The energetically lowest lying form of [H2 E- E(H)- EH2]-, ·,+ ( E = Si - Sn) has a cyclic structure for the neutral molecules and the anion and a quasi-cyclic equilibrium arrangement for the cations. In contrast, the cyclic isomers of the carbon molecules [H2C-C(H)-CH2]-, ·,+ are significantly higher in energy than the allyl structures. Energy decomposition analyses show that the lower stability of the planar C2 v allyl structures of [H2 E- E(H)- EH2]-, ·,+ ( E = Si - Sn) does not come from weak π conjugation. The relative contribution of π conjugation in the latter species is even higher than in the allyl system of carbon. The cyclic form of [H2 E- E(H)- EH2]-, ·,+ ( E = Si - Sn) is lower in energy than the allyl form, because the σ bonding in the former structures is much stronger than in the latter. This overcompensates the higher Pauli repulsion in the cyclic form. In the carbon systems, the Pauli repulsion of the cyclic structures is very strong, because the bonds are much shorter than in the heavier homologues. Consequently, the stronger Pauli repulsion in the cyclic isomers is not compensated by the stronger attraction compared with the allyl system. [ABSTRACT FROM AUTHOR]

Abstract: Several novel 3-allyl-2-(substituted imino)-4-phenyl-3H-thiazole derivatives were synthesized by the reaction of allyl-thioureas and 2-bromoacetophenone. We also report the synthesis of bis-allyl-3H thiazoles using the reaction of various isothiocyanates and 1,3-phenylenediamine. The structures of all compounds were characterized by spectral and elemental analysis. Most of the synthesized compounds exhibited efficient antibacterial activities against Salmonella enterica, Micrococcus luteus, Bacillus subtilis and Pseudomonas aeruginosa. [Copyright &y& Elsevier]

Abstract: As part of our research program dedicated to the design and synthesis of new iminosugars as pharmacological chaperones for the treatment of lysosomal storage disorders, we developed a rapid and efficient methodology for the access to functionalized and non-functionalized 1-C-alkylated derivatives in the d-xylo and l-arabino series. These compounds, as gluco and galacto mimics, were designed to be potent inhibitors of, respectively, β-glucocerebrosidase, involved in Gaucher disease, and β-galactocerebrosidase, responsible for Krabbe disease. The key step of the synthesis is the diastereoselective addition of allyltrimethylsilane to the d-xylo or l-arabino N-benzyloxycarbonyl protected glycopyranosylamine. This protective group allows the direct functionalization of the obtained iminosugars using metathesis or oxidation reactions. For determination of the absolute configuration of dihydroxylation reaction products the in situ dimolybdenum methodology of electronic circular dichroism spectroscopy was successfully used. [Copyright &y& Elsevier]

The mechanism of the palladium-catalyzed synthesis of allylic silanes and boronates from allylic alcohols was investigated. ¹H, 29Si, 19F, and 11B NMR spectroscopy was used to reveal key intermediates and byproducts of the silylation reaction. The tetrafluoroborate counterion of the palladium catalyst is proposed to play an important role in both catalyst activation as well as the transmetalation step. We propose that BF3 is generated in both processes and is responsible for the activation of the substrate hydroxyl group. An (η³-allyl)palladium complex has been identified as the catalyst resting state, and the formation of (η³-allyl)palladium complexes directly from allylic alcohols has been studied. Kinetic analysis provides evidence that the turnover limiting step is the transmetalation, and insights into notable similarities between the borylation and the silylation reaction mechanisms enabled us to considerably improve the stereoselectivity of the borylation. [ABSTRACT FROM AUTHOR]

Chiral ion pairs play a key role in modern enantioselective synthesis, though little is known about their properties. We have now used the special features of unsymmetrically substituted allyl derivatives to obtain unprecedented insight into ion pair dynamics. By employing chiral high-performance liquid chromatography, it was possible to follow the time-dependent concentrations of all four isomeric esters (two regioisomeric pairs of enantiomers) and all four isomeric alcohols generated during the hydrolysis of enantiopure 1-(4-chlorophenyl)-3-phenylallyl and 3-(4-chlorophenyl)-1-phenylallyl 4-nitrobenzoates. Combination of these results with the directly measured rate constant for the reaction of the laser-flash photolytically generated 1-(4-chlorophenyl)-3-phenylallyl cation with water provided a complete mechanistic scheme for allyl carboxylate solvolysis. It is demonstrated that solvolysis and internal return can be explained by the same intermediates. The correlation equation log k = sN(N + E) was used to elucidate the variable importance of external and internal return in the solvolysis reactions. This information will be crucial for the interpretation of the ultrafast dynamics of ion pairs generated by femtosecond laser pulses. [ABSTRACT FROM AUTHOR]

A novel method where 3,3′-allyl dithioethers have been prepared from 3-mercapto-2-mercaptomethylprop-1-ene and two mol equivalent of alkyl halide in the presence of two mol equivalent of sodium hydride has been developed. Using this method, bisepoxide, 2,2′-(2-methylenepropane-1,3-diyl)bis(sulfanediyl)bis(methylene)dioxirane (8) has been synthesized from epichlorohydrin, whereas potassium carbonate was unable to deliver this product. These 3,3′-allyl dithioethers can be utilized either as monomers, or with further chemical reactions transformed into more complex monomers, for photoplastic polymer networks. Difunctional monomers with various polymerizable end groups and containing 3,3´-allyl dithioethers in the centre of the chain, have been prepared using two different alkylation methods. These allyl dithioethers can be polymerized directly, or with further chemical reactions transformed into more complex monomers, for photoplastic polymer networks, illustrated by one example. [ABSTRACT FROM AUTHOR]

A palladium-catalyzed coupling of allylic carbonates with trimethylsilylisocyanate to provide allylic isocyanates is reported. Amines are added in a second step to yield allylic ureas in this one-pot procedure. Use of a bidentate phosphine ligand with a large bite angle was found to be important in this transformation. The scope of allylic carbonates has been examined, as well as amines compatible with these reaction conditions. [ABSTRACT FROM AUTHOR]

In search for novel heterocyclization processes, the intramolecular Pd-mediated allylic alkylation of homoallyl hydroxyl�amines is described. Depending on both the reaction conditions and the substrates, cis- or trans-3-substituted-5-vinyl isoxazolidines are preferentially obtained. The corresponding starting materials for the cyclization step are readily obtained through cross-metathesis of the easily accessible unsubstituted homoallyl hydroxylamines. [ABSTRACT FROM AUTHOR]

Rhodium-catalyzed regio- and enantioselective coupling of tetrazoles with allenes are reported. Asymmetric construction of tertiary and quaternary allylic C–N bonds were achieved using a Rh(i)/JoSPOphos catalyst. This method permits the atom-economic synthesis of various valuable N2-allylic tetrazoles. [ABSTRACT FROM AUTHOR]

The article discusses a research concerning the chemical reaction of selenium dihalides with allyl benzyl ether. Details about the reaction of selenium dihalides with vinyl ethers are noted, highlighting the Markovnikov adducts in high yield the reaction corresponds. Also provided is information on the procedure in carrying out the reactions, which involved carbon tetrachloride or chloroform at room temperature.

An efficient method for Pd-catalyzed stereospecific allyl–aryl coupling of allylic alcohols with arylboronic acids has been described. The reactions proceeded smoothly in the presence of Pd2(dba)3·CHCl3 and racemic BINAP under mild and neutral conditions, affording allyl–aryl coupling products in moderate to high yields with excellent stereospecificities. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to a study that describes the reaction of diacetylene with allyl bromide to yield a compound capable of explosive decomposition.

The article focuses on the synthesis of the 1-allyl-3,5-dimethyl-1H-pyrazole-4-carbaldehyde (I) and propane-1,3-diselenol (II) in the presence of Me3SiCl catalyst. It says that the preparation of propane-1,3-diselenol (II) was performed by reductive cleavage of the Selenium bond in polytrimrthylene diselenide in the N2H4·H2O—KOH. It states that the reaction accompanied with heat evolution was completed in five minutes.

The oxidation reactions are effectively and economically performed under mild conditions. [ABSTRACT FROM AUTHOR]

The article presents the process of catalysis with 1,3-Dipolar Cycloadditions of 4-Acetoxy Allenoates and access to 2,3 Dihydropyrazoles, 2,3-Dihydroisoxazoles, and Indolizines

Zn-promoted double allylation and propargylation of imidates with allyl- and propargyl bromides provides the title compounds in good yields. [ABSTRACT FROM AUTHOR]

N-Boc- or N-Cbz-protected α-amino sulfones are allylated with allyl acetate derivatives. [ABSTRACT FROM AUTHOR]

Various dialkyl substituted allyl boronates are condensed with aromatic and aliphatic aldehydes. [ABSTRACT FROM AUTHOR]