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One new oxovanadium(IV) phosphate material, [H2en]4[V7P8O35(OH)6(H2O)]·3H2O was prepared utilizing a one step, mild hydrothermal route involving ethylenediamine as the reducing agent. The compound was structurally characterized by single crystal and powder X-ray diffraction methods and found to crystallize in the monoclinic space group C2/c. The temperature dependence of the magnetic susceptibility of was measured and found to be paramagnetic down to 2 K. The compound was further characterized by IR and UV–Vis spectroscopies.

We report an efficient methodology for the direct oxidative esterification of primary alcohols to diether-esters using pyridinium chlorochromate (PCC). Numerous studies were carried out to probe the reaction mechanism and at the same time optimize the reaction conditions. The reaction could be conducted with 1 equivalent of PCC and 1 equivalent of BF3·OEt2. Indications based on literature precedent were that the reaction may proceed via a sequential alcohol oxidation to the aldehyde followed by a putative Cr or boron catalyzed Claisen–Tishchenko-type reaction. Using this efficient methodology, we synthesized a family of novel diether-esters in very good yields; some of these molecules were subsequently tested against both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). In addition, we also disclose a new synthetic strategy for the synthesis of lactam macrocycles with potential biological activity. This methodology included the regioselective borylation of the ester substrate and a subsequent Suzuki–Miyaura coupling to obtain the desired lactam macrocycle.

A strategy toward the biomimetic synthesis of morusalbanol A pentamethyl ether is described. The synthesis is based on a hydrogen-bond-assisted Diels–Alder cycloaddition between a dehydroprenyl diene and a chalcone dienophile. Selective cleavage of the ortho-methyl ether of the resulting cycloadduct allows rotation of the C3–C21 bond and subsequent intramolecular cyclization affords the pentamethyl ether of (±)-morusalbanol A. As with the natural product, morusalbanol A, a number of key proton and carbon signals are absent in the NMR spectra of the title product.

Single crystals of La0.516(3)Na0.484(3)MoO4, Ce0.512(2)Na0.488(2)MoO4, Pr0.502(2)Na0.498(2)MoO4, Nd0.501(2)Na0.499(2)MoO4, Sm0.509(2)Na0.491(2)MoO4, and Eu0.603(2)Na0.397(2)MoO4 were grown for the first time out of an alkali metal halide eutectic flux. All compounds crystallize in the tetragonal space group I41/a. UV/Vis measurements show the presence of an absorption edge for all compounds except Eu0.603(2)Na0.397(2)MoO4. The temperature dependence of the magnetic susceptibility was measured for all compounds and found to be paramagnetic across the entire 2–300 K temperature range measured.

Chiral 3-amino-3-aryloxindoles are important biologically active compounds. Using a catalytic modular approach, 31 new 3-amino-3-aryl-2-oxindoles were prepared by a simple Rh-catalysed addition of arylboronic acids to isatin-derived N-Boc-protected ketimines (Boc = tert-butoxycarbonyl). A low catalyst loading of 3 mol-% was used, and the reaction showed a wide scope with high functional-group compatibility, and gave good yields. We report the first catalytic enantioselective reactions with this substrate. Deprotection of the Boc group was easily accomplished in good yields.

Substituted oxocene derivatives have been synthesized by Lewis acid catalyzed reactions of e-hydroxyalkene and substituted aromatic aldehydes. The Cu(OTf)2-bis-phosphine catalyzed reaction typically provides substituted dihydropyran derivatives through an olefin migration followed by a Prins cyclization. The corresponding reaction catalyzed by TMSOTf or BF3·OEt2 provided eight-membered cyclic ethers (oxocenes), selectively. This methodology provides convenient access to a variety of 2,4,8-trisubstituted oxocenes in good yields and excellent diastereoselectivities.

1-Aminotetraline, 1-aminoindane, and benzocycloalkanol structures are privileged scaffolds demonstrating broad ranging pharmacological properties. In this review recent advances in the synthesis of molecules containing these scaffolds via metal catalyzed intramolecular aryl additions to activated groups like: imines, ketones, and aldehydes are discussed.

The key step of the title synthesis is Pd-catalyzed C—N coupling of o-bromoaldimines with o-bromoanilines.

Five new lanthanide molybdenum oxides containing mixed valent Mo(IV/V) rutile-like chains, Ln5Mo2O12 Ln = Eu, Tb, Dy, Ho, and Er, were prepared utilizing a high-temperature molten salt flux synthesis involving an in situ reduction utilizing metallic reducing agents. All five compounds were structurally characterized by single-crystal and powder X-ray diffraction methods and were found to crystallize in the monoclinic space group C2/m. The molybdates all contain rare infinite chains consisting of MoO2O4/2 edge-sharing octahedra. The chains exhibit alternating long and short separations between octahedra caused by the presence of Mo–Mo bonds to form Mo2O10 units containing one unpaired electron. The temperature dependence of the magnetic susceptibility of these compounds was measured, and antiferromagnetic ordering was observed in all cases.

We report the development of a tertiary amine-containing β-turn peptide that catalyzes the atroposelective bromination of pharmaceutically relevant 3-arylquinazolin-4(3H)-ones (quinazolinones) with high levels of enantioinduction over a broad substrate scope. The structure of the free catalyst and the peptide–substrate complex were explored using X-ray crystallography and 2D-NOESY experiments. Quinazolinone rotational barriers about the chiral anilide axis were also studied using density functional theory calculations and are discussed in light of the high enantioselectivities observed. Mechanistic studies also suggest that the initial bromination event is stereodetermining, and the major monobromide intermediate is an atropisomerically stable, mono-ortho-substituted isomer. The observation of stereoisomerically stable monobromides stimulated the conversion of the tribromide products to other atropisomerically defined products of interest. For example, (1) a dehalogenation Suzuki–Miyaura cross-coupling se...

Single crystals of Ba3Na0.32Nb6O12(Si2O7)2 were grown for the first time. The use of an alkali/alkaline earth eutectic flux facilitated the crystal growth. Ba3Na0.32Nb6O12(Si2O7)2, a mixed valent Nb(V)/Nb(IV) compound, crystallizes in the noncentrosymmetric hexagonal space group P-62m with a = 8.9998(10) A and c = 7.8119(17) A. The temperature dependence of the magnetic susceptibility was measured and found to be paramagnetic across the entire 2–300 K temperature range measured. Although noncentrosymmetric, Ba3Na0.32Nb6O12(Si2O7)2 was not found to be second harmonic generation active. Ba3Na0.32Nb6O12(Si2O7)2 was further characterized by IR and UV/Vis spectroscopies.

The use of a KCl/CsCl alkali eutectic flux under reducing conditions facilitated the crystal growth of the mixed valent Mo(V)/Mo(VI) compound La20Mo12O63Cl4. La20Mo12O63Cl4 crystallizes in the noncentrosymmetric hexagonal space group P-62m with a = 10.2241(2) A and c = 15.0768(4) A, which represents a new structure type exhibiting a three-dimensional crystal structure containing three different molybdenum coordination environments, MoO5 square pyramids, MoO6 trigonal prisms, and MoO5 trigonal bipyramids. The temperature dependence of the magnetic susceptibility was measured and La20Mo12O63Cl4 was found to be paramagnetic across the entire 2–300 K temperature range measured. Although noncentrosymmetric, La20Mo12O63Cl4 was not found to be second harmonic generation active. La20Mo12O63Cl4 was further characterized by UV/Vis spectroscopy.

A diastereoselective approach to deoxypropionate derivatives through Pd/C-catalyzed hydrogenolysis of enantioenriched ketene heterodimers is described. Catalytic hydrogenolysis of the Z-isomer of ketene heterodimers facilitates access to anti-deoxypropionate derivatives (10 examples with dr 7:1 to >20:1). Transfer of chirality from the Z-ketene heterodimer to an acid product was good to excellent in most cases (78–99% ee for 12 examples).

The photothermally induced title reaction is catalyzed by a pendant iron carbonyl moiety and provides diastereomerically pure spirotricyclic products in high yields.

The efficient metal-catalyzed intramolecular cyclization of amidoarylboronic acid aldehydes (I), (III), (V) is the key step in the simple three step synthesis of a library of chiral isoquinolinone derivatives with aryl (II), pyridyl (IV), and thiophene (VI) cores.

1,2,3-Triazoles find applications in several major technological areas, and especially in drug discovery. The click-chemistry approaches based on Huisgen’s cycloaddition reaction are particularly attractive and have received enormous attention over the last decade and a half, due to their utility in preparing compounds with diverse applications, from drugs to linkers for bioconjugation.

Several cinchona-derived catalysts are synthesized and successful applied to the enantioselective reduction of ketomines.

Several amino acids and dipeptides are coupled in good overall yields to furnish chinchonidine derivatives.

Herein we report the first application of Rh(I)–phosphane and phosphane–phosphite catalysts in the enantioselective catalytic arylation of ethyl glyoxylate with organoboron reagents, providing access to ethyl mandelate derivatives in high yield (up to 99%) and moderate to very good enantioselectivities (up to 75% ee). Commercial phosphane ligands, such as (R)-MonoPhos and (R)-Phanephos were tested, as well as non-commercial (R,R)-TADDOL-derived phosphane–phosphite ligands. Those ligands containing bulky substituents in the ortho-and para-positions of the chiral phosphite moiety were found to be the most selective.

Adsorbed water is present on nearly all surfaces exposed to the ambient and can greatly influence tribological properties such as adhesion, friction and wear. This paper reviews how the effects of the surface chemistry, such as oxidised or terminated by different functional groups, greatly influences the water adsorption isotherm thickness as well as the structure of adsorbed water. The thickness and activity of the adsorbed water greatly affect the wear between different material surfaces. Sufficient adsorbed water could induce a detrimental effect such as galvanic corrosion between dissimilar metals or a beneficial effect strengthening soda lime glass.

It is found that the tetrapeptide (PET) efficiently promotes the dynamic kinetic resolution of various oxazolones like (I) giving α-amino acid esters with up to 94% e.e..

The development of title compound (I), one of the most potent and selective orexin 2 antagonists (2-SORA) reported to date, is described including SAR study.

An efficient protocol for the double symmetrical arylation using aryl bromides, one-pot or sequential arylation using two different aryl bromides or monoarylation of difluorobenzothiadiazole is developed.

Title compound (I) is converted to a series of α-amino acids (III) using two catalytic systems.

This describes the synthesis of pseudopeptide organocatalysts and their application in the asymmetric aldol reaction to yield compounds (III).

Mild oxidation of zwitterionic azolium alkoxides (I) and (III) under anhydrous conditions leads to new stable spirocyclic ketals (II) and (IV).

The arylation of ethyl glyoxalate in the presence of chiral Rh(I)-NHC catalysts provides ethyl mandelate derivatives with very low enantioselectivities.

Novel bis(imidazole-2-thion-4-yl)- phosphanes (2a–d) were synthesized via lithiation of the precursor imidazole-2-thiones followed by the phosphanylation reaction. Oxidation of bis(imidazole-2-thion-4-yl)phosphane 2b–d with elemental sulfur and selenium led selectively and in good yields to the P-thio (3b–d) and P-seleno (4c) derivatives of bis(imidazole-2-thion-4-yl)phosphanes, respectively. The treatment of 2a,c with phosphorus trichloride gives the corresponding P-chloro derivatives 5a,c. These compounds were unambiguously characterized by elemental analyses, spectroscopic and spectrometric methods, in addition by single-crystal X-ray structure analysis in the case of 2d. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 00:1–7, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21043

Heating of Fe complexes of type (I) followed by demetalation allows a stereoselective access to spirocyclic lactams like (IV) - (VI).

For the first time, we report the application of [RuCl2(η6-p-cymene)]2 in the arylation of N-activated aldimines with boronic acids and its derivatives to afford chiral amines, which are important intermediates in the syntheses of key bioactive compounds. The behavior of the chiral ligands, the imine substrates, and the organoboron reagents were studied. Very good enantioselectivities were obtained.

Various catalysts are investigated and it is found that modification of the structure by introducing a second stereogenic center improves the yields and the enantioselectivities.

Several N-prolinylanthranilic acid derivatives can be used as bifunctional organocatalysts in the direct asymmetric aldol reaction of cyclohexanone with aromatic aldehydes.

The production of chiral amines by means of catalytic asymmetric synthesis is a current challenge in the field of drug discovery and is discussed in this review. The use of cheap, easily handled, and low toxic organoboron reagents, such as boronic acids and derivatives, and easily prepared imine substrates, such as diphenylphosphinoyl, N-Boc, N-tosylaryl, N-nosylaryl, or dimethylsulfamoyl imines, together with rhodium and palladium catalysts give the corresponding chiral amine products in excellent yields and enantioselectivities. A diverse range of chiral ligands, such as phosphines, phosphites, phosphoramidites, P,O-ligands, olefins, NHCs, and N,N-ligands can be used with this method, showing, therefore, its versatility. The application of aliphatic imine substrates and with the use of different palladium complexes show, on the other hand, the versatility of the method described.

The reaction allows an efficient access to a number of β-alkylated and arylated vinylogous esters.

A range of ephedrine-like ligands is prepared varying mainly the N-benzyl moiety of original ephedrine.

Reaction of (2,2′-[o-phenylenebis(methylenethio)]bis[ethanamine])copper(II) in alcoholic base with formaldehyde and nitroethane yields the macrocycle (8-methyl-8-nitro-6,10-diaza-3,13-dithia-1,15,16,17,18,19-dehydrobicyclo[13.4.0]nonadecane)copper (II), which incorporates an ortho-xylene unit as part of a 15-membered macrocyclic ring with cis-N2S2 donors which also carry pendent nitro and methyl groups. Zinc-acid reduction of the complex permits isolation of a potentially quinquedentate N3S2-donor ligand.