μ-Bromido-dibromido-μ-hydroxido-bis­[(4S)-2-halo-6-(4-isopropyl-4,5-dihydro­oxazol-2-yl)pyridine]dicopper(II) (halo: Cl/Br = 3:1)

The crystal structure of the title complex, [Cu2Br3(OH)(C11H13Br0.5Cl1.5N2O)2], consists of two (2-halo-6-oxazolin­yl)pyridine·CuBr units bridged by a Br atom and a hydroxide group. The CuII atoms are five-coordinate with an (N,N)BrCu(Br)(OH) distorted tetra­gonal–pyramidal core, and relatively short contacts to the bridging atoms (Cu—μ-OH and Cu—μ-Br). There are two symmetry-independent half-mol­ecules in the asymmetric unit, which differ only in the arrangement of the isopropyl group. The mol­ecules are located on a twofold rotation axes

Preparation data of the bromodomains BRD3(1), BRD3(2), BRD4(1), and BRPF1B and crystallization of BRD4(1)-inhibitor complexes

AbstractThis article presents detailed purification procedures for the bromodomains BRD3(1), BRD3(2), BRD4(1), and BRPF1B. In addition we provide crystallization protocols for apo BRD4(1) and BRD4(1) in complex with numerous inhibitors. The protocols described here were successfully applied to obtain affinity data by isothermal titration calorimetry (ITC) and by differential scanning fluorimetry (DSF) as well as structural characterizations of BRD4(1) inhibitor complexes (PDB codes: PDB: 4LYI, PDB: 4LZS, PDB: 4LYW, PDB: 4LZR, PDB: 4LYS, PDB: 5D24, PDB: 5D25, PDB: 5D26, PDB: 5D3H, PDB: 5D3J, PDB: 5D3L, PDB: 5D3N, PDB: 5D3P, PDB: 5D3R, PDB: 5D3S, PDB: 5D3T). These data have been reported previously and are discussed in more detail elsewhere [1,2]

The Effect of Chemical Doping and Hydrostatic Pressure on Tc of Y1-yCayBa2Cu3Ox Single Crystals

We performed susceptibility measurements on Y1-yCayBa2Cu3Ox single crystals under high He pressure. For each Ca content various samples with different oxygen contents have been prepared to probe the influence of Ca on Tc(x), dTc/dp(x) and Tc,max. Starting from the parabolic Tc(nh) behavior we calculated nh values from Tc and Tc,max for each sample. It is shown that in the overdoped region dTc/dp can be described by a pressure induced charge transfer with dnh/dp = 3.7E-3 [1/GPa] and a dTc,max/dp value of 0.8 K/GPa, irrespective of the Ca content. In the underdoped region additional pressure effects lead to a peak in dTc/dp at approximately 0.11 holes/CuO2 plane. However, with increasing Ca content this peak is strongly depressed. This is explained in terms of an increasing disorder in the CuO chain system due to doping. Deviations in dTc/dp at very low nh values can be assigned to the ortho II ordering in the CuO chain system.Comment: 13 pages with 6 figures, accepted for publication in Physica

Uranium mobility in organic matter-rich sediments: A review of geological and geochemical processes

Uranium (U) is of enormous global importance because of its use in energy generation, albeit with potential environmental legacies. While naturally occurring U is widespread in the Earth's crust at concentrations of ~1 to 3 ppm, higher concentrations can be found, includingwithin organicmatter (OM)-rich sediments, leading to economic extraction opportunities. The primary determinants of U behaviour in ore systems are pH, Eh, U oxidation state (U(IV), U(VI)) and the abundance of CO3 2– ions. The concentration/availability and interrelationships among such determinants vary, and the solubility and mobility of ions (e.g. OH-, CO3 2–, PO4 3-, SiO4 4-, SO4 2-) that compete for U (primarily as U(VI)) will also influence the mobility of U. In addition, the presence of OM can influence U mobility and fate by the degree of OMsorption to mineral surfaces (e.g. Fe- and Si- oxides and hydroxides). Within solid-phase OM, microbes can influence U oxidation state and U stability through direct enzymatic reduction, biosorption, biomineralisation and bioaccumulation. The biogenic UO2 product is, however, reported to be readily susceptible to reoxidation and therefore more likely remobilised over longer time periods. Thus several areas of uncertainty remain with respect to factors contributing to U accumulation, stability and/or (re)mobilisation. To address these uncertainties, this paper reviews U dynamics at both geological and molecular scales. Here we identify U-OMbond values that are in agreement, relatively strong, independent from ionic strength and which may facilitate either U mobilisation or immobilisation, depending on environmental conditions. We also examine knowledge gaps in the literature, with U-OM solubility data generally lacking in comparison to data for U sorption and dissolution, and little information available on multi-component relationships, such as UOM-V (V as vanadate). Furthermore, the capability ofOMto influence the oxidation state of U at near surface conditions remains unclear, as it can be postulated that electron shuttling by OM may contribute to changes in U redox state otherwise mediated by bacteria. Geochemical modelling of the environmental mobility of U will require incorporation of data from multi-corporation studies, as well as from studies of U-OM microbial interactions, all of which are considered in this review

Organophotoredox/Ni-Cocatalyzed Allylation of Allenes: Regio-, and Diastereoselective Access to Homoallylic Alcohols

A dual organophotoredox/nickel-catalyzed reductive coupling of allenes with aldehydes has been developed for the rapid assembly of anti-homoallylic alcohols with high levels of regioselectivities (>20:1), and diastereoselectivities (up to >20:1) and yields (up to 91%). The allylation was realized through a crucial π-allylnickel intermediate which was obtained via insertion of allenes with a Ni−H intermediate. Moreover, γ,γ-disubstituted homoallylic alcohols with a quaternary stereocenter can also be prepared by this protocol

Chemo‑, Regio‑, and Enantioselective Rhodium-Catalyzed Allylation of Triazoles with Internal Alkynes and Terminal Allenes

The rhodium-catalyzed asymmetric <i>N</i>¹-selective and regioselective coupling of triazole derivatives with internal alkynes and terminal allenes gives access to secondary and tertiary allylic triazoles in very good enantioselectivities. For this process, three new members of the JosPOphos ligand family have been prepared and employed in catalysis. The optimized reaction conditions enable the coupling of triazoles with internal alkynes as well as with allenes, displaying a high tolerance for functional groups. A gram scale reaction provided <i>N</i>¹-allyltriazole, which was subjected to various transformations highlighting synthetic utility

Rhodium-Catalyzed Dynamic Kinetic Resolution of Racemic Internal Allenes towards Chiral Allylated Triazoles and Tetrazoles

A general Rh-catalyzed addition reaction of nitrogen containing heterocycles to internal allenes is reported. Starting from racemic internal allenes a dynamic kinetic resolution (DKR) provides N-allylated triazoles and tetrazoles. Simultaneous control of N1/Nx-position selectivity, enantioselectivity and olefin geometry gives access to important building blocks of target-oriented synthesis. The synthetic utility is demonstrated by a gram-scale reaction and a broad substrate scope tolerating multiple functional groups. Deuterium labeling experiments and experiments with enantioenriched allenes as starting material support a plausible reaction mechanism