Scope and limitation of organocuprates, and copper or nickel catalyst-modified Grignard reagents for installation of an alkyl group onto cis-4-cyclopentene-1,3-diol monoacetate

Alkylation of the title compound 1 was investigated with two types of reagents. One is a copper reagent derived from R(T)MgX (X = Cl, Br) and CuX (X = CN, I) and the other is R(T)MgX in the presence of a copper or a nickel catalyst. First, butylation was studied with BuCu(CN)(MgX), Bu(2)Cu(CN)(MgX)(2), BuMgX/CuCN (10 mol %), BuCu (derived from BuMgCl and CuI), and BuMgCl/CuI (10 mol %) in THF or Et(2)O. We found that trans 1,4-isomer 2a and/or trans 1,2-isomer 3a were produced exclusively with these reagents and that the stoichiometry of BuMgX/CuX and the choice of solvent were critical to attain high regioselectivity and efficient yield. Reaction with Bu(2)Cu(CN)(MgCl)(2) and BuMgCl/CuX (X = CN, I; 10 mol %) both in THF produced 2a with 93-94% regioselectivity in 87-92% yields. On the other hand, BuCu(CN)(MgX) in THF, Bu(2)Cu(CN)(MgX)(2) in Et(2)O, and BuMgX/CuCN (10 mol %) in Et(2)O furnished 3a in good yields with >90% selectively, irrespective of X of BuMgX. In the nickel-catalyzed butylation of 1 with BuMgCl, NiCl(2)(dppp) among NiCl(2)(tpp)(2), NiCl(2)(dppf), and NiCl(2)(dppp) furnished the best result to produce 2a. The CuCN-based protocol was then applied to other alkyl Grignard reagents, which include Me, Et, (CH(2))(3)Ph, c-C(6)H(11), (CH(2))(6)OMOM, (CH(2))(9)CH=CH(2), and CH(2)Ph as the alkyl group (R(T)). In addition, the Mitsunobu inversion of 2a and 3a afforded the corresponding cis isomers stereoselectively with AcOH as an acid at -78 degrees C in toluene for 2a and with 4-(NO(2))C(6)H(4)COOH in THF at r.t. for 3a. No racemization during the alkylation was confirmed by the reaction using (1R,3S)-1 (>99% ee) to produce (1S,4S)-2a and (1S,2S)-3a, respectively.     

Electrophoresis and orientation of multiple wall carbon nanotubes in polymer solution

This paper contains an in-depth analysis of the electrophoresis of multi-wall carbon nanotubes (MWNTs) in liquid epoxy where electrophoresis experiments under DC and AC fields were carried out for five different types of multi-wall carbon nanotubes (MWNTs). DC electrophoresis and particle image velocimetry were used to determine the electrophoretic particle mobility and zeta potential, where the MWNTs with the largest outer diameter and length led to the highest mobility values. The orientation and agglomeration of MWNTs into “striation” lines under AC electrophoresis were investigated by analysing the hue, saturation and intensity of the transmitted polarised light under microscope, following a schedule of step-wise applied voltage in the range of 0 to 100 V. Plots of hue and saturation as a function of the applied voltage were used to assess the degree of orientation and density of orientated MWNT structures, respectively, and to determine an optimum AC electric field value for the orientation of a specific MWNT type by electrophoresis.     

A Facile Synthesis of 5‐Phenyl‐Dibenzo[b,g][1,8]Napthyridines

The Vilsmeier Haack heterocyclization of 2‐aryl amino‐4‐phenyl quinolines quinoline yielded the hitherto unknown 5‐phenyl‐dibenzo[b,g][1,8]naphthyridines in quantitative yield. The synthesis of aryl amines was achieved by the action of anilines on 2‐chloro‐4‐phenyl quinoline, which in turn was sourced through the combes reaction of benzoyl acetanilides.     

Development and validation of a highly sensitive LC-MS/MS method for simultaneous quantitation of acetyl-CoA and malonyl-CoA in animal tissues

A highly sensitive and specific LC‐MS/MS method was developed for simultaneous estimation of acetyl co‐enzyme A (ACoA) and malonyl co‐enzyme A (MCoA) in surrogate matrix using n‐propionyl co‐enzyme A as an internal standard (IS). LC‐MS/MS was operated under the multiple reaction‐monitoring mode using the electrospray ionization technique. Simple acidification followed by dilution using an assay buffer process was used to extract ACoA, MCoA and IS from surrogate matrix and tissue samples. The total run time was 3 min and the elution of both analytes (ACoA, MCoA) and IS occurred at 1.28 min; this was achieved with a mobile phase consisting of 5 mM ammonium formate (pH 7.5)–acetonitrile (30:70, v/v) delivered at a flow rate of 1 mL/min on a monolithic RP‐18e column. A linear response function was established for the range of concentrations 1.09–2187 and 1.09–2193 ng/mL for ACoA and MCoA, respectively. The intra‐ and inter‐day precision values for ACoA and MCoA met the acceptance as per FDA guidelines. ACoA and MCoA were stable in a battery of stability studies viz. bench‐top, auto‐sampler and long‐term. The developed assay was used to quantitate ACoA and MCoA levels in various tissues of rat. Copyright © 2011 John Wiley & Sons, Ltd.     

Spin-Transfer-Torque driven magneto-logic OR, AND and NOT gates

We show that current induced magneto-logic gates like AND, OR and NOT can be designed with the simple architecture involving a single nano spin-valve pillar, as an extension of our recent work on spin-torque-driven magneto-logic universal gates, NAND and NOR. Here the logical operation is induced by spin-polarized currents which also form the logical inputs. The operation is facilitated by the simultaneous presence of a constant controlling magnetic field, in the absence of which the same element operates as a magnetoresistive memory element. We construct the relevant phase space diagrams for the free layer magnetization dynamics in the monodomain approximation and show the rationale and functioning of the proposed gates. The flipping time for the logical states of these non-universal gates is estimated to be within nano seconds, just like their universal counter parts.     

New geometries associated with the nonlinear Schrödinger equation

We apply our recent formalism establishing new connections between the geometry of moving space curves and soliton equations, to the nonlinear Schr?dinger equation (NLS). We show that any given solution of the NLS gets associated with three distinct space curve evolutions. The tangent vector of the first of these curves, the binormal vector of the second and the normal vector of the third, are shown to satisfy the integrable Landau-Lifshitz (LL) equation = ×, ( = 1). These connections enable us to find the three surfaces swept out by the moving curves associated with the NLS. As an example, surfaces corresponding to a stationary envelope soliton solution of the NLS are obtained. Received 5 December 2001 Published online 2 October 2002 RID="a" ID="a"e-mail: radha@imsc.ernet.in     

Suppression of plasma turbulence during optimized shear configurations in JET

Correlation of density turbulence suppression and reduced plasma transport is observed in the internal transport barrier (ITB) region of JET tokamak discharges with optimized magnetic shear. The suppression occurs in two stages. First, low frequency turbulence and ion transport are reduced across the plasma core by a toroidal velocity shear generated by intense auxiliary heating. Then with the ITB formation, high frequency turbulence and electron transport are reduced locally within the steep pressure gradient region of the ITB.     

Derivation,Functionalization of (S)-Goniothalamin from Goniothalamus wightii and Their Derivative Targets SARS-CoV-2 MPro,SPro, and RdRp: A Pharmacological Perspective

The tracing of an alternative drug, Phytochemicals is a promising approach to the viral threats that have emerged over the past two years. Across the world, herbal medicine is a better solution against anti-viral diseases during pandemic periods. Goniothalamus wightii is an herbal plant, which has diverse bioactive compounds with anticancer, antioxidant, and anti-viral properties. The aim of the study was to isolate the compound by chromatography studies and functionalization by FT-IR, LC-MS, and NMR (C-NMR, H-NMR). As a result, the current work focuses on whether (S)-Goniathalamin and its analogue could act as natural anti-viral molecules for multiple target proteins viz., M^Pro, RdRp, and S^Pro, which are required for SARS-CoV-2 infection. Overall, 954 compounds were examined and the molecular-docking studies were performed on the maestro platform of Schrodinger software. Molecular-dynamics simulation studies were performed on two complex major compounds to confirm their affinity across 150 simulations. This research suggests that plant-based drugs have high levels of antiviral properties against coronavirus. However, more research is needed to verify its antiviral properties.     

On the kinematics of 2+1-dimensional motions of a fibre-reinforced fluid. Integrable connections

Evolution of foliations of the plane is shown, under a conditionof constant divergence, to be linked to the scattering problemfor the integrable modified Korteweg–de Vries hierarchy.This result is applied to a set of kinematic relations whicharise in the theory of ideal fibre-reinforced fluids. In particular,it is established that the fibres, which are convected withthe fluid, constitute generalized tractrices.