D-Fructose-based spiro-fused PHOX ligands: synthesis and application in enantioselective allylic alkylation

Phosphinooxazoline (PHOX) ligands are an important class of ligands in asymmetric catalysis. We synthesized ten novel D-fructose-derived spiro-fused PHOX ligands with different steric and electronic demand. The application of two of them was tested in asymmetric allylic alkylation. The ligands are prepared in two steps from readily available 1,2-O-isopropylidene protected β-D-fructopyranoses by the BF3·OEt2-promoted Ritter reaction with 2-bromobenzonitrile to construct the oxazoline moiety followed by Ullmann coupling of the resulting aryl bromides with diphenylphosphine. Both steps proceeded mostly in good to high yields (57–86% for the Ritter reaction and 35–89% for the Ullmann coupling). The Ritter reaction gave two anomers, which could be separated by column chromatography. The prepared ligands showed promising results (er of up to 84:16) in Tsuji–Trost reactions with diphenylallyl acetate as model substrate

Computing the LS factor for the Revised Universal Soil Loss Equation through array-based slope processing of digital elevation data using a C++ executable

Until the mid-1990s, a major limitation of using the Universal Soil Loss Equation and Revised Universal Soil Loss Equation erosion models at regional landscape scales was the difficulty in estimating LS factor (slope length and steepness) values suitable for use in geographic information systems applications. A series of ArcInfo™ Arc Macro Language scripts was subsequently created that enabled the production of either USLE- or RUSLE-based LS factor raster grids using a digital elevation model input data set. These scripts have functioned exceptionally well for both single- and multiple-watershed applications within targeted study areas. However, due to the nature and complexity of flowpath processing necessary to compute cumulative slope length, the scripts have not taken advantage of available computing resources to the extent possible. It was determined that the speed of the computer runs could be significantly increased without sacrificing accuracy in the final results by performing the majority of the elevation data processing in a two-dimensional array framework outside the ArcInfo environment. This paper describes the evolution of a major portion of the original RUSLE-based AML processing code to an array-based executable program using ANSI C++™ software. Examples of the relevant command-line arguments are provided and comparative results from several AML-vs.-executable time trials are also presented. In wide-ranging areas of the United States where it has been tested, the new RUSLE-based executable has produced LS-factor values that mimic those generated by the original AML as well as the RUSLE Handbook estimates. Anticipated uses of the executable program include water quality assessment, landscape ecology, land-use change detection studies, and decision support activities. This research has now given users the option of either running the executable file alone to process a single watershed reporting unit or running a supporting AML shell program that calls upon the executable file as necessary to perform automated processing for a user-specified number of watersheds

In vitro transcription of herpes simplex virus ANG DNA by E-coli RNA polymerase.

HSV-1 ANG DNA and a defective genome of the same virus were transcribed with E. coli RNA polymerase under various salt conditions. The extent of transcription was assayed by hybridizing the cRNA to the Hind III, Hpa I and Hind II restriction fragments of the DNA templates using the blot technique of E. Southern. The transcripts proved to contain sequences homologous to all DNA fragments. A similar ratio of hybridized cRNA and the amount of fragment DNA was observed in all cases. The results suggest that both, the wt and the defective HSV ANG genome were completely transcribed

Synthesis and crystal structure of a self-assembled, octanuclear oxo-tantalum(V) derivative containing the first example of a transition metal M8(mu-O)12 cage

By reduction with CoCp*(2) in THF or toluene, the tantalum(V) chlorocarbamato complex TaCl2(O2CNEt2)(3), 1, gives high yields of the tantalum(III) N,N-diethylcarbamate, Ta(O2CNEt2)(3), 2. On the other hand, good yields of the octanuclear mu-oxo-N,N-diethylcarbamato cage compound Ta-8(mu-O)(12)(O2CNEt2)(16), 3, were secured by reaction of 1 with sodium in THF. Compound 3 has been characterized by analytical and spectroscopic methods and by X-ray diffractometry. Crystal data for C80H160N16O44Ta8: M = 3497.84, triclinic, space group P (1) over bar (no. 2), (1) over bar a = 15.440(3) Angstrom, b = 15.710(1).Angstrom, c = 16.090(2) Angstrom, alpha = 101.53(4)degrees, beta = 107.51(5)degrees, gamma = 118.79(3)degrees, V = 2971.4(3) Angstrom(3), Z = 1, D-c = 1.955: Mg/m(3), mu = 7.416 mm(-1), F(000) = 1688, R1 = 0.0350, wR2 = 0.0798, T = 213 K. The eight tantalum atoms are located at the vertexes of a cube whose edges are occupied by 12 bridging oxo groups; Hexacoordination at tantalum is completed by bridging and terminal N,N-diethylcarbamato ligands. Both THF and the carbon dioxide fragments of the carbamato groups are involved in the formation of the mu-oxo cage oxides

Effects of Ginger and Expectations on Symptoms of Nausea in a Balanced Placebo Design

OBJECTIVE: Ginger effects on (experimental) nausea have been described, but also strong placebo effects and sex differences when nausea is involved. The "balanced placebo design" has been proposed to allow better separation of drug and placebo effects. METHODS: Sixty-four healthy participants (32 women) were randomly assigned to receive an antiemetic ginger preparation or placebo, and half of each group was told to have received drug or placebo. They were exposed to 5×2 min body rotations to induce nausea. Subjective symptoms and behavioral (rotation tolerance, head movements) and physiological measures (electrogastrogram, cortisol) were recorded. Groups were balanced for sex of participants and experimenters. RESULTS: Ginger and the information given did not affect any outcome measure, and previous sex differences could not be confirmed. Adding the experimenters revealed a significant four-factorial interaction on behavioral but not on subjective or physiological measures Men who received placebo responded to placebo information when provided by the male experimenter, and to ginger information when provided by the female experimenter. This effect was not significant in women. CONCLUSION: The effects of an antiemetic drug and provided information interact with psychosocial variables of participants and experimenters in reports of nausea

Effects of ginger and expectations on symptoms of nausea in a balanced placebo design.

OBJECTIVE: Ginger effects on (experimental) nausea have been described, but also strong placebo effects and sex differences when nausea is involved. The "balanced placebo design" has been proposed to allow better separation of drug and placebo effects. METHODS: Sixty-four healthy participants (32 women) were randomly assigned to receive an antiemetic ginger preparation or placebo, and half of each group was told to have received drug or placebo. They were exposed to 5×2 min body rotations to induce nausea. Subjective symptoms and behavioral (rotation tolerance, head movements) and physiological measures (electrogastrogram, cortisol) were recorded. Groups were balanced for sex of participants and experimenters. RESULTS: Ginger and the information given did not affect any outcome measure, and previous sex differences could not be confirmed. Adding the experimenters revealed a significant four-factorial interaction on behavioral but not on subjective or physiological measures Men who received placebo responded to placebo information when provided by the male experimenter, and to ginger information when provided by the female experimenter. This effect was not significant in women. CONCLUSION: The effects of an antiemetic drug and provided information interact with psychosocial variables of participants and experimenters in reports of nausea